In this paper, new radio access scheme that combines Amplify-and-Forward (AF) relaying protocol and non-orthogonal multiple access (NOMA) system is introduced. In particular, different scenarios for fixed power allocation scheme is investigated. In addition, the outage probability of both weak and strong user is derived and provided in closed-form expressions. Such outage is investigated in high SNR scenario and comparison performance between these NOMA scenarios is introduced. Numerical simulations are offered to clarify the outage performance of the considered scheme if varying several parameters in the existing schemes to verify the derived formulas.
Enabling relay selection in non-orthogonal multiple access networks: direct a...TELKOMNIKA JOURNAL
In this paper, we consider downlink non-orthogonal multiple access (NOMA) in which the relay selection (RS) scheme is enabled for cooperative networks. In particular, we investigate impact of the number of relays on system performance in term of outage probability. The main factors affecting on cooperative NOMA performance are fixed power allocations coefficients and the number of relay. This paper also indicate performance gap of the outage probabilities among two users the context of NOMA. To exhibit the exactness of derived formula, we match related results between simulation and analytical methods. Numerical results confirms that cooperative NOMA networks benefit from increasing the number of relay.
Tractable computation in outage performance analysis of relay selection NOMATELKOMNIKA JOURNAL
In recent years, using full-duplex (FD) transmission model provides enhanced bandwidth efficiency and improved performance for non-orthogonal multiple access (NOMA) system. However, lack of papers have investigated FD relay together with relay selection issue to improve performance of NOMA system. The problems in power allocation for two NOMA users satisfying fairness as well as relay selection strategy are studied in this paper. By considering the outage performance of proposed scheme with its vital result, general NOMA wireless networks can be developed for future networks due to its improved performance. Simulation results show that the relaying selection scheme can achieve a significant performance improvement by increasing required quantity of relay.
Hybrid decode-amplify and forward protocol of FD EH relaying network: outage ...TELKOMNIKA JOURNAL
Nowadays, many research papers focus on the WPCN problem and how to improve its
efficiency. In this research, we propose and investigate Hybrid Decode-Amplify and Forward Protocol
(HDAF) of the Full-Duplex (FD) Energy Harvesting (EH) Relaying Network with the Time Switching (TS)
protocol. In the beginning stage, we present the HDAF mode, which can be work like a
Decode-and-Amplify (DF) or Amplify-and-Forward (AF) modes based on the best of its performance in the
FD EH relaying network. Furthermore, the closed-form expression of the outage probability (OT) is
analyzed and derived in connection with the primary system parameters. Besides, the comparison of
the system performance in the AF, DF, and HDAF is proposed and investigated. Finally, all the results are
convinced by the Monte Carlo simulation for all cases.
This document analyzes site selection diversity transmission (SSDT) for 3GPP WCDMA forward link and compares it to hard handover (HHO) and soft handover (SHO). It finds that SSDT can provide performance gains over HHO and SHO, but these gains may be reduced by feedback bit errors. The performance of each method is modeled and analyzed mathematically to derive bit error probability expressions as a function of signal-to-noise ratio. Feedback bit errors are also accounted for in the SSDT analysis.
This document summarizes a research paper that proposes using Discrete Logarithmic Method (DLM) to reduce Peak-to-Average Power Ratio (PAPR) in Multi-Carrier Code Division Multiple Access (MC-CDMA) wireless systems. It describes how DLM, previously used in cryptography, can be applied to encode binary data as triplets for transmission. The encoding reduces PAPR without increasing bit error rate. It then outlines the MC-CDMA transmitter and receiver block diagrams, explaining how binary to DLM encoding is used before transmission and DLM to binary decoding is used upon reception. Simulation results showed over 5dB reduction in PAPR.
Study on outage performance gap of two destinations on CR-NOMA networkTELKOMNIKA JOURNAL
This document studies the outage performance of two secondary destinations in a cognitive radio non-orthogonal multiple access (CR-NOMA) network. It presents a system model of a downlink dual-hop CR-NOMA network consisting of a primary destination, secondary source, relay, and two secondary destinations. It derives the exact outage probability expressions for the secondary users by obtaining the signal-to-interference-plus noise ratio and signal-to-noise ratio for each transmission. The results show that the performance gap between the two secondary users can be obtained due to different power allocation factors assigned to each user.
This document proposes a physical-layer network coding (PNC) scheme to improve throughput in wireless networks. PNC takes advantage of the broadcast nature of wireless transmissions by allowing signals from multiple nodes to be combined at the physical layer through modulation and demodulation. It demonstrates PNC for a three-node wireless linear network. With PNC, the three nodes can exchange information in two time slots, improving throughput by 100% over traditional scheduling and 50% over straightforward network coding. PNC mapping provides a way to perform network coding operations on electromagnetic signals directly at the physical layer by mapping their combination to binary additions.
Ber performance analysis of mimo systems using equalizationAlexander Decker
The document discusses equalization techniques for analyzing bit error rate (BER) performance in multiple-input multiple-output (MIMO) systems. It analyzes different equalization techniques like zero forcing (ZF), minimum mean squared error (MMSE), ZF with successive interference cancellation (ZF-SIC), MMSE with SIC (MMSE-SIC), maximum likelihood (ML) and sphere decoding. Simulation results show that successive interference methods outperform ZF and MMSE, but have higher complexity. ML provides better performance than others, while sphere decoding gives the best performance but highest complexity compared to ML.
Enabling relay selection in non-orthogonal multiple access networks: direct a...TELKOMNIKA JOURNAL
In this paper, we consider downlink non-orthogonal multiple access (NOMA) in which the relay selection (RS) scheme is enabled for cooperative networks. In particular, we investigate impact of the number of relays on system performance in term of outage probability. The main factors affecting on cooperative NOMA performance are fixed power allocations coefficients and the number of relay. This paper also indicate performance gap of the outage probabilities among two users the context of NOMA. To exhibit the exactness of derived formula, we match related results between simulation and analytical methods. Numerical results confirms that cooperative NOMA networks benefit from increasing the number of relay.
Tractable computation in outage performance analysis of relay selection NOMATELKOMNIKA JOURNAL
In recent years, using full-duplex (FD) transmission model provides enhanced bandwidth efficiency and improved performance for non-orthogonal multiple access (NOMA) system. However, lack of papers have investigated FD relay together with relay selection issue to improve performance of NOMA system. The problems in power allocation for two NOMA users satisfying fairness as well as relay selection strategy are studied in this paper. By considering the outage performance of proposed scheme with its vital result, general NOMA wireless networks can be developed for future networks due to its improved performance. Simulation results show that the relaying selection scheme can achieve a significant performance improvement by increasing required quantity of relay.
Hybrid decode-amplify and forward protocol of FD EH relaying network: outage ...TELKOMNIKA JOURNAL
Nowadays, many research papers focus on the WPCN problem and how to improve its
efficiency. In this research, we propose and investigate Hybrid Decode-Amplify and Forward Protocol
(HDAF) of the Full-Duplex (FD) Energy Harvesting (EH) Relaying Network with the Time Switching (TS)
protocol. In the beginning stage, we present the HDAF mode, which can be work like a
Decode-and-Amplify (DF) or Amplify-and-Forward (AF) modes based on the best of its performance in the
FD EH relaying network. Furthermore, the closed-form expression of the outage probability (OT) is
analyzed and derived in connection with the primary system parameters. Besides, the comparison of
the system performance in the AF, DF, and HDAF is proposed and investigated. Finally, all the results are
convinced by the Monte Carlo simulation for all cases.
This document analyzes site selection diversity transmission (SSDT) for 3GPP WCDMA forward link and compares it to hard handover (HHO) and soft handover (SHO). It finds that SSDT can provide performance gains over HHO and SHO, but these gains may be reduced by feedback bit errors. The performance of each method is modeled and analyzed mathematically to derive bit error probability expressions as a function of signal-to-noise ratio. Feedback bit errors are also accounted for in the SSDT analysis.
This document summarizes a research paper that proposes using Discrete Logarithmic Method (DLM) to reduce Peak-to-Average Power Ratio (PAPR) in Multi-Carrier Code Division Multiple Access (MC-CDMA) wireless systems. It describes how DLM, previously used in cryptography, can be applied to encode binary data as triplets for transmission. The encoding reduces PAPR without increasing bit error rate. It then outlines the MC-CDMA transmitter and receiver block diagrams, explaining how binary to DLM encoding is used before transmission and DLM to binary decoding is used upon reception. Simulation results showed over 5dB reduction in PAPR.
Study on outage performance gap of two destinations on CR-NOMA networkTELKOMNIKA JOURNAL
This document studies the outage performance of two secondary destinations in a cognitive radio non-orthogonal multiple access (CR-NOMA) network. It presents a system model of a downlink dual-hop CR-NOMA network consisting of a primary destination, secondary source, relay, and two secondary destinations. It derives the exact outage probability expressions for the secondary users by obtaining the signal-to-interference-plus noise ratio and signal-to-noise ratio for each transmission. The results show that the performance gap between the two secondary users can be obtained due to different power allocation factors assigned to each user.
This document proposes a physical-layer network coding (PNC) scheme to improve throughput in wireless networks. PNC takes advantage of the broadcast nature of wireless transmissions by allowing signals from multiple nodes to be combined at the physical layer through modulation and demodulation. It demonstrates PNC for a three-node wireless linear network. With PNC, the three nodes can exchange information in two time slots, improving throughput by 100% over traditional scheduling and 50% over straightforward network coding. PNC mapping provides a way to perform network coding operations on electromagnetic signals directly at the physical layer by mapping their combination to binary additions.
Ber performance analysis of mimo systems using equalizationAlexander Decker
The document discusses equalization techniques for analyzing bit error rate (BER) performance in multiple-input multiple-output (MIMO) systems. It analyzes different equalization techniques like zero forcing (ZF), minimum mean squared error (MMSE), ZF with successive interference cancellation (ZF-SIC), MMSE with SIC (MMSE-SIC), maximum likelihood (ML) and sphere decoding. Simulation results show that successive interference methods outperform ZF and MMSE, but have higher complexity. ML provides better performance than others, while sphere decoding gives the best performance but highest complexity compared to ML.
Outage performance of downlink NOMA-aided small cell network with wireless po...journalBEEI
This article considers the outage performance of the downlink transmission for a small cell network in a heterogeneous network. Due to mobility and distribution of users, it is necessary to study massive connections and high energy efficiency for such kind of systems. To be an enabler of energy harvesting, a power beacon is helpful to support the base station to send signals to distant users, and wireless power transfer (WPT) is exploited to guarantee the data packets transmission from the power beacon to the base station. To provide massive connections, we propose a novel non-orthogonal multiple access (NOMA) technique combined with WPT to enhance outage performance and latency reduction. Furthermore, we derive outage probability (OP) to characterize the system performance. Simulation results are verified to match well between theoretical and analytical methods, and main parameters are determined to understand how they affect the proposed scheme.
Outage probability analysis of EH NOMA system network over Rayleigh fading ch...journalBEEI
Non-orthogonal multiple access (NOMA) with advantages such as superior spectral efficiency has been considered as a promising multiple access technique for the fifth-generation (5G) mobile networks. In this research, we propose energy harvesting (EH) NOMA system relaying network over Rayleigh fading channel using selection combining at the receiver. Firstly, we investigate the system performance in terms of the closed-form expression of the outage probability (OP). Here we compare the OP of two destination users of the proposed system. Finally, all the results is convinced by the Monte Carlo simulation. From the results, we can confirm that all the analytical and simulation results are the same in connection with the primary system parameters.
This document discusses multiple access protocols for shared communication channels. It begins by explaining how data is framed and transmitted over shared links at the data link layer. It then covers three main categories of multiple access protocols: random access, controlled access, and channelization. Random access protocols like ALOHA and slotted ALOHA are described, as well as controlled access methods using reservation, polling, and token passing. Finally, channelization protocols for dividing access using frequency, time, or code (FDMA, TDMA, CDMA) are introduced. Examples are provided to illustrate load calculations and sequencing.
System performance evaluation of fixed and adaptive resource allocation of 3 ...Alexander Decker
This document discusses and compares fixed and adaptive (dynamic) resource allocation strategies for 3GPP LTE downlink interfaces. It finds that an adaptive subcarrier allocation based on user channel quality information performs better than fixed allocation by optimizing the allocation of network resources. The key points are:
1) Fixed allocation dedicates specific subcarriers to each user, even if they are not being used, wasting resources. Adaptive allocation uses channel quality information to allocate subcarriers dynamically based on user needs.
2) Simulation results show that adaptive allocation, which allocates more subcarriers to users with better channel conditions, optimizes resource use compared to fixed allocation.
3) The objective of adaptive allocation is to find a
Adaptive relaying protocol for wireless energy harvesting and information pro...journalBEEI
In order to satisfy the increasing data rate demands, the research in the fifth-generation (5G) wireless networks is ongoing, both in academia and industry. In this research, we propose and investigate adaptive relaying protocol (ARP) For wireless energy harvesting (EH) and information processing in NOMA systems. Firstly, we investigate and derive the closed-form and integral-form expressions of the outage probability (OP) of the model system. Then, all the results are convinced by the Monte Carlo simulation. The research results show that all the analytical and simulation results are the same in connection with the primary system parameters. This research can provide a recommendation for NOMA system network.
The document reports on an experimental study of the hidden node problem in IEEE 802.11 wireless networks. The experiments show that:
1) Transmission ranges and carrier sensing ranges differ from NS2 simulator defaults, dropping more gradually with distance.
2) Using RTS/CTS does not solve the hidden node problem and reduces throughput due to overhead.
3) "Re-routing instability" seen in simulations occurs in real networks, degrading throughput.
4) There is an "optimal offered load" that maximizes end-to-end throughput in multi-hop flows.
This document proposes a physical-layer network coding (PNC) scheme to improve capacity in wireless networks. PNC takes advantage of the broadcast nature of wireless transmissions by allowing signals from multiple nodes to be combined at the receiver using network coding principles. Specifically:
- PNC coordinates transmissions so that signals from different nodes arrive simultaneously at the relay node, where they are combined using modulation mapping that performs network coding operations in the physical layer.
- This allows the relay node to transmit a single coded signal, requiring fewer time slots than schemes that avoid or separate interfering signals.
- In a basic three-node example network, PNC allows information exchange between the two outer nodes in two time slots, compared
Performance analysis for power-splitting energy harvesting based two-way full...TELKOMNIKA JOURNAL
Energy harvesting relay network is considered as the promising solution for a wireless
communication network in our time. In this research, we present and demonstrate the system performance
of the energy harvesting based two-way full-duplex relaying network over Nakagami-m fading
environment. Firstly, we propose the analytical expressions of the achievable throughput and outage
probability of the proposed system. In the second step, the effect of various system parameters on
the system performance is presented and investigated. In the final step, the analytical results are also
demonstrated by Monte-Carlo simulation. The numerical results demonstrated and convinced
the analytical and the simulation results are agreed with each other.
1) The document describes the downlink physical channels of LTE including the DL-SCH, PBCH, PDSCH, PDCCH, PCFICH, and PHICH.
2) It discusses design constraints for LTE including keeping the cyclic prefix smaller than the symbol length and larger than the delay spread to avoid overhead and interference. The subcarrier spacing must also be large enough to overcome Doppler shifts from UE motion.
3) The placement of reference signals is described, needing to be spaced at least every 0.5ms in time to track fast channels and every 6 subcarriers (45kHz) in frequency to resolve variations.
Enhancing Downlink Performance in Wireless Networks by Simultaneous Multiple ...ambitlick
This document discusses enhancing the downlink performance of wireless networks through simultaneous multiple packet transmission (MPT). MPT allows an access point to simultaneously transmit two packets to two distinct users, effectively doubling throughput. The paper formalizes scheduling packets for transmission as a maximum matching problem in a graph. It also presents a fast approximation algorithm for finding a matching and analyzes how MPT can increase maximum arrival rates and reduce packet delays.
This document summarizes the results of a simulation study measuring the performance of different medium access control configurations in a wireless local area network. It finds that enabling the point coordination function reduces delay and increases throughput by reducing collisions. Having more stations participate in the contention-free period when PCF is enabled further reduces delay. Fragmentation increases delay due to the additional processing needed to fragment and reassemble frames. Enabling PCF on all stations had the lowest delay, while only enabling it on two stations and using fragmentation had the highest delay.
This document analyzes peak-to-average power ratio (PAPR) reduction techniques for single carrier frequency division multiple access (SC-FDMA) signals used in 3GPP Long Term Evolution (LTE) networks. It proposes applying a combination of clipping and pulse shaping using a root raised cosine (RRC) filter to an SC-FDMA signal with interleaved frequency division multiple access (IFDMA) subcarrier mapping. Simulation results show this hybrid technique reduces PAPR compared to using RRC filtering alone, with greater reduction at higher RRC roll-off factors and larger block sizes. The PAPR reduction improves power efficiency for mobile devices.
This document describes the design and analysis of a single-ended inductively degenerated interstage matched common-source cascode CMOS low noise amplifier (LNA). The LNA is implemented using a 90nm CMOS process. It employs a cascode topology with single-ended source degeneration using an inductor to achieve high gain. An interstage inductor between the common source and common gate stages is used to further increase the overall gain. Simulation results show the LNA has a noise figure of 1.986dB at 2.4GHz, a voltage gain of 19.1dB, and operates with low noise and high gain as required for applications such as wireless communications.
The document discusses the key requirements for 4G networks including high bandwidth, long distance, low power consumption, and high speed mobility. It then examines the characteristics of different duplexing techniques used in today's networks, specifically Frequency Division Duplex (FDD) and Time Division Duplex (TDD). The challenges of TDD including cross-slot interference and outdated channel information are also outlined, along with potential solutions like synchronization and sectorization. In conclusion, TDD allows for asymmetric traffic allocation and higher bit-rates using unpaired spectrum bands compared to FDD.
1. The target MSC sends a paging request to the target mobile station through base stations. 2. If the mobile station responds, it is authenticated and ciphering is enabled for security. 3. Radio resources are assigned and the connection is established between the mobile station and MSC to complete the call setup through the base station.
The performance of turbo codes for wireless communication systemschakravarthy Gopi
This document describes and compares two algorithms for decoding turbo codes: the Soft-Output Viterbi Algorithm (SOVA) and the Logarithmic Maximum A Posteriori (Log-MAP) algorithm. It provides simulations results that show the Log-MAP algorithm achieves 0.4 dB better bit error rate performance than SOVA for turbo codes with a constraint length of 3 over an additive white Gaussian noise channel. The document is arranged into sections that describe the channel model, each decoding algorithm, iterative decoding principles, and simulation results comparing the two algorithms' performance for different block lengths.
Evaluation of STBC and Convolutional Code Performance for Wireless Communicat...theijes
Under rich dissipating environment, Multiple Input Multiple Output (MIMO) scheme have better performance in term of reliability and increasing the throughput. Space Time Block Code (STBC) can reduce the Bit Error Rate (BER) with suitable data rate. In order to raise the amount of throughput more, high modulation order is used but it degrade the performance. To address this problem, a Convolutional Code (CC) can be support such system with various code rate to deal with different circumstances. This research is proposed a system with serial concatenation of STBC and CC with various modulation levels. Such system is tested with Rayleigh flat and selective fading channel by Matlab package R2015b with a list of modulation order and changing the code of each STBC and CC. The results show that such system can cover a range of Signal to Noise Ratio (SNR) from 0 to 21 dB of SNR for selective fading channel and -2 to 19 dBfor flat fading channel for a targeted BER of 10-4 with a various modulation index and code rate which lead to a flexible system to change the throughput depending on user conditions.
The document discusses different types of switched networks, including circuit-switched networks, datagram networks, and virtual-circuit networks. It provides examples of how each type can be used and their characteristics. The document also describes the structure of switches used in different network types, including crossbar switches, multistage switches, time-slot interchange switches, and banyan switches. Key aspects like resource reservation, routing, addressing, and delays are compared between the different network types.
Dcf learn and performance analysis of 802.11 b wireless networkIJCNCJournal
Though WLAN wireless network has been widely deployed as the main split-flow deployment of the
communication network, little study emphasizes its performance as WLAN protocols were only designed for
the public communicating conveniently with each other. Actually that too much wireless access points
assembling together will cause self-interference to the whole WLAN network. This paper investigates the
distributed coordination function (DCF) learn and the performance study of 802.11b networks. Firstly, our
study illustrates the performance of its MAC layer and its fairness issues related to DCF. Next we propose
the details which should be paid attention to in deploying network services. Then, performance analyses
are evaluated by simulation and real test for a dense wireless network. Our main goal is to give proposals
to network operators how to design a WLAN network more standardized and orderly.
The document discusses bandwidth utilization techniques including multiplexing and spreading. Multiplexing allows simultaneous transmission of multiple signals across a single data link by dividing the bandwidth into channels. Efficiency is achieved through multiplexing while privacy and anti-jamming is achieved through spreading techniques that add redundancy such as frequency hopping spread spectrum and direct sequence spread spectrum. The document provides examples and figures to illustrate concepts such as frequency-division multiplexing, time-division multiplexing, and digital signal hierarchies.
Security performance analysis for power domain NOMA employing in cognitive ra...journalBEEI
The power domain non-orthogonal multiple access (NOMA) technique introduces one of the fundamental characteristics and it exhibits the possibility of users to decode the messages of the other paired users on the same resources. In cognitive radio inspired NOMA (CR-NOMA), the base station (BS) has to serve untrusted users or users with different security clearance. This phenomenon raises a security threat particularly in such CR-NOMA. This paper develops a tractable analysis framework to evaluate the security performance of cooperative non-orthogonal multiple access (NOMA) in cognitive networks, where relay is able to serve two far NOMA users in the presence of external eavesdropper. In particular, we study the secrecy outage probability in a two-user NOMA system. This situation happens in practical the BS is pairing a legitimate user with another untrusted user. Main reason is that the non-uniform distribution in terms of trusted and untrusted users in the cell. By performing numerical results demonstrate the performance improvements of the proposed NOMA scheme in comparison to that of several situations in terms of different parameters. Furthermore, the security performance of NOMA is shown to verify the derived expressions.
Comparison study on secrecy probability of AF-NOMA and AF-OMA networksTELKOMNIKA JOURNAL
1) The document compares the secrecy probability performance of amplify-and-forward non-orthogonal multiple access (AF-NOMA) networks and amplify-and-forward orthogonal multiple access (AF-OMA) networks in the presence of an eavesdropper.
2) It derives an upper bound expression for the strictly positive secrecy capacity (SPSC) of the AF-NOMA network, which represents the probability that the instantaneous secrecy rates are positive.
3) The analysis shows that the SPSC of NOMA is significantly lower than OMA due to the channel characterization of NOMA, but it can be improved by optimizing the power allocation coefficients.
Outage performance of downlink NOMA-aided small cell network with wireless po...journalBEEI
This article considers the outage performance of the downlink transmission for a small cell network in a heterogeneous network. Due to mobility and distribution of users, it is necessary to study massive connections and high energy efficiency for such kind of systems. To be an enabler of energy harvesting, a power beacon is helpful to support the base station to send signals to distant users, and wireless power transfer (WPT) is exploited to guarantee the data packets transmission from the power beacon to the base station. To provide massive connections, we propose a novel non-orthogonal multiple access (NOMA) technique combined with WPT to enhance outage performance and latency reduction. Furthermore, we derive outage probability (OP) to characterize the system performance. Simulation results are verified to match well between theoretical and analytical methods, and main parameters are determined to understand how they affect the proposed scheme.
Outage probability analysis of EH NOMA system network over Rayleigh fading ch...journalBEEI
Non-orthogonal multiple access (NOMA) with advantages such as superior spectral efficiency has been considered as a promising multiple access technique for the fifth-generation (5G) mobile networks. In this research, we propose energy harvesting (EH) NOMA system relaying network over Rayleigh fading channel using selection combining at the receiver. Firstly, we investigate the system performance in terms of the closed-form expression of the outage probability (OP). Here we compare the OP of two destination users of the proposed system. Finally, all the results is convinced by the Monte Carlo simulation. From the results, we can confirm that all the analytical and simulation results are the same in connection with the primary system parameters.
This document discusses multiple access protocols for shared communication channels. It begins by explaining how data is framed and transmitted over shared links at the data link layer. It then covers three main categories of multiple access protocols: random access, controlled access, and channelization. Random access protocols like ALOHA and slotted ALOHA are described, as well as controlled access methods using reservation, polling, and token passing. Finally, channelization protocols for dividing access using frequency, time, or code (FDMA, TDMA, CDMA) are introduced. Examples are provided to illustrate load calculations and sequencing.
System performance evaluation of fixed and adaptive resource allocation of 3 ...Alexander Decker
This document discusses and compares fixed and adaptive (dynamic) resource allocation strategies for 3GPP LTE downlink interfaces. It finds that an adaptive subcarrier allocation based on user channel quality information performs better than fixed allocation by optimizing the allocation of network resources. The key points are:
1) Fixed allocation dedicates specific subcarriers to each user, even if they are not being used, wasting resources. Adaptive allocation uses channel quality information to allocate subcarriers dynamically based on user needs.
2) Simulation results show that adaptive allocation, which allocates more subcarriers to users with better channel conditions, optimizes resource use compared to fixed allocation.
3) The objective of adaptive allocation is to find a
Adaptive relaying protocol for wireless energy harvesting and information pro...journalBEEI
In order to satisfy the increasing data rate demands, the research in the fifth-generation (5G) wireless networks is ongoing, both in academia and industry. In this research, we propose and investigate adaptive relaying protocol (ARP) For wireless energy harvesting (EH) and information processing in NOMA systems. Firstly, we investigate and derive the closed-form and integral-form expressions of the outage probability (OP) of the model system. Then, all the results are convinced by the Monte Carlo simulation. The research results show that all the analytical and simulation results are the same in connection with the primary system parameters. This research can provide a recommendation for NOMA system network.
The document reports on an experimental study of the hidden node problem in IEEE 802.11 wireless networks. The experiments show that:
1) Transmission ranges and carrier sensing ranges differ from NS2 simulator defaults, dropping more gradually with distance.
2) Using RTS/CTS does not solve the hidden node problem and reduces throughput due to overhead.
3) "Re-routing instability" seen in simulations occurs in real networks, degrading throughput.
4) There is an "optimal offered load" that maximizes end-to-end throughput in multi-hop flows.
This document proposes a physical-layer network coding (PNC) scheme to improve capacity in wireless networks. PNC takes advantage of the broadcast nature of wireless transmissions by allowing signals from multiple nodes to be combined at the receiver using network coding principles. Specifically:
- PNC coordinates transmissions so that signals from different nodes arrive simultaneously at the relay node, where they are combined using modulation mapping that performs network coding operations in the physical layer.
- This allows the relay node to transmit a single coded signal, requiring fewer time slots than schemes that avoid or separate interfering signals.
- In a basic three-node example network, PNC allows information exchange between the two outer nodes in two time slots, compared
Performance analysis for power-splitting energy harvesting based two-way full...TELKOMNIKA JOURNAL
Energy harvesting relay network is considered as the promising solution for a wireless
communication network in our time. In this research, we present and demonstrate the system performance
of the energy harvesting based two-way full-duplex relaying network over Nakagami-m fading
environment. Firstly, we propose the analytical expressions of the achievable throughput and outage
probability of the proposed system. In the second step, the effect of various system parameters on
the system performance is presented and investigated. In the final step, the analytical results are also
demonstrated by Monte-Carlo simulation. The numerical results demonstrated and convinced
the analytical and the simulation results are agreed with each other.
1) The document describes the downlink physical channels of LTE including the DL-SCH, PBCH, PDSCH, PDCCH, PCFICH, and PHICH.
2) It discusses design constraints for LTE including keeping the cyclic prefix smaller than the symbol length and larger than the delay spread to avoid overhead and interference. The subcarrier spacing must also be large enough to overcome Doppler shifts from UE motion.
3) The placement of reference signals is described, needing to be spaced at least every 0.5ms in time to track fast channels and every 6 subcarriers (45kHz) in frequency to resolve variations.
Enhancing Downlink Performance in Wireless Networks by Simultaneous Multiple ...ambitlick
This document discusses enhancing the downlink performance of wireless networks through simultaneous multiple packet transmission (MPT). MPT allows an access point to simultaneously transmit two packets to two distinct users, effectively doubling throughput. The paper formalizes scheduling packets for transmission as a maximum matching problem in a graph. It also presents a fast approximation algorithm for finding a matching and analyzes how MPT can increase maximum arrival rates and reduce packet delays.
This document summarizes the results of a simulation study measuring the performance of different medium access control configurations in a wireless local area network. It finds that enabling the point coordination function reduces delay and increases throughput by reducing collisions. Having more stations participate in the contention-free period when PCF is enabled further reduces delay. Fragmentation increases delay due to the additional processing needed to fragment and reassemble frames. Enabling PCF on all stations had the lowest delay, while only enabling it on two stations and using fragmentation had the highest delay.
This document analyzes peak-to-average power ratio (PAPR) reduction techniques for single carrier frequency division multiple access (SC-FDMA) signals used in 3GPP Long Term Evolution (LTE) networks. It proposes applying a combination of clipping and pulse shaping using a root raised cosine (RRC) filter to an SC-FDMA signal with interleaved frequency division multiple access (IFDMA) subcarrier mapping. Simulation results show this hybrid technique reduces PAPR compared to using RRC filtering alone, with greater reduction at higher RRC roll-off factors and larger block sizes. The PAPR reduction improves power efficiency for mobile devices.
This document describes the design and analysis of a single-ended inductively degenerated interstage matched common-source cascode CMOS low noise amplifier (LNA). The LNA is implemented using a 90nm CMOS process. It employs a cascode topology with single-ended source degeneration using an inductor to achieve high gain. An interstage inductor between the common source and common gate stages is used to further increase the overall gain. Simulation results show the LNA has a noise figure of 1.986dB at 2.4GHz, a voltage gain of 19.1dB, and operates with low noise and high gain as required for applications such as wireless communications.
The document discusses the key requirements for 4G networks including high bandwidth, long distance, low power consumption, and high speed mobility. It then examines the characteristics of different duplexing techniques used in today's networks, specifically Frequency Division Duplex (FDD) and Time Division Duplex (TDD). The challenges of TDD including cross-slot interference and outdated channel information are also outlined, along with potential solutions like synchronization and sectorization. In conclusion, TDD allows for asymmetric traffic allocation and higher bit-rates using unpaired spectrum bands compared to FDD.
1. The target MSC sends a paging request to the target mobile station through base stations. 2. If the mobile station responds, it is authenticated and ciphering is enabled for security. 3. Radio resources are assigned and the connection is established between the mobile station and MSC to complete the call setup through the base station.
The performance of turbo codes for wireless communication systemschakravarthy Gopi
This document describes and compares two algorithms for decoding turbo codes: the Soft-Output Viterbi Algorithm (SOVA) and the Logarithmic Maximum A Posteriori (Log-MAP) algorithm. It provides simulations results that show the Log-MAP algorithm achieves 0.4 dB better bit error rate performance than SOVA for turbo codes with a constraint length of 3 over an additive white Gaussian noise channel. The document is arranged into sections that describe the channel model, each decoding algorithm, iterative decoding principles, and simulation results comparing the two algorithms' performance for different block lengths.
Evaluation of STBC and Convolutional Code Performance for Wireless Communicat...theijes
Under rich dissipating environment, Multiple Input Multiple Output (MIMO) scheme have better performance in term of reliability and increasing the throughput. Space Time Block Code (STBC) can reduce the Bit Error Rate (BER) with suitable data rate. In order to raise the amount of throughput more, high modulation order is used but it degrade the performance. To address this problem, a Convolutional Code (CC) can be support such system with various code rate to deal with different circumstances. This research is proposed a system with serial concatenation of STBC and CC with various modulation levels. Such system is tested with Rayleigh flat and selective fading channel by Matlab package R2015b with a list of modulation order and changing the code of each STBC and CC. The results show that such system can cover a range of Signal to Noise Ratio (SNR) from 0 to 21 dB of SNR for selective fading channel and -2 to 19 dBfor flat fading channel for a targeted BER of 10-4 with a various modulation index and code rate which lead to a flexible system to change the throughput depending on user conditions.
The document discusses different types of switched networks, including circuit-switched networks, datagram networks, and virtual-circuit networks. It provides examples of how each type can be used and their characteristics. The document also describes the structure of switches used in different network types, including crossbar switches, multistage switches, time-slot interchange switches, and banyan switches. Key aspects like resource reservation, routing, addressing, and delays are compared between the different network types.
Dcf learn and performance analysis of 802.11 b wireless networkIJCNCJournal
Though WLAN wireless network has been widely deployed as the main split-flow deployment of the
communication network, little study emphasizes its performance as WLAN protocols were only designed for
the public communicating conveniently with each other. Actually that too much wireless access points
assembling together will cause self-interference to the whole WLAN network. This paper investigates the
distributed coordination function (DCF) learn and the performance study of 802.11b networks. Firstly, our
study illustrates the performance of its MAC layer and its fairness issues related to DCF. Next we propose
the details which should be paid attention to in deploying network services. Then, performance analyses
are evaluated by simulation and real test for a dense wireless network. Our main goal is to give proposals
to network operators how to design a WLAN network more standardized and orderly.
The document discusses bandwidth utilization techniques including multiplexing and spreading. Multiplexing allows simultaneous transmission of multiple signals across a single data link by dividing the bandwidth into channels. Efficiency is achieved through multiplexing while privacy and anti-jamming is achieved through spreading techniques that add redundancy such as frequency hopping spread spectrum and direct sequence spread spectrum. The document provides examples and figures to illustrate concepts such as frequency-division multiplexing, time-division multiplexing, and digital signal hierarchies.
Security performance analysis for power domain NOMA employing in cognitive ra...journalBEEI
The power domain non-orthogonal multiple access (NOMA) technique introduces one of the fundamental characteristics and it exhibits the possibility of users to decode the messages of the other paired users on the same resources. In cognitive radio inspired NOMA (CR-NOMA), the base station (BS) has to serve untrusted users or users with different security clearance. This phenomenon raises a security threat particularly in such CR-NOMA. This paper develops a tractable analysis framework to evaluate the security performance of cooperative non-orthogonal multiple access (NOMA) in cognitive networks, where relay is able to serve two far NOMA users in the presence of external eavesdropper. In particular, we study the secrecy outage probability in a two-user NOMA system. This situation happens in practical the BS is pairing a legitimate user with another untrusted user. Main reason is that the non-uniform distribution in terms of trusted and untrusted users in the cell. By performing numerical results demonstrate the performance improvements of the proposed NOMA scheme in comparison to that of several situations in terms of different parameters. Furthermore, the security performance of NOMA is shown to verify the derived expressions.
Comparison study on secrecy probability of AF-NOMA and AF-OMA networksTELKOMNIKA JOURNAL
1) The document compares the secrecy probability performance of amplify-and-forward non-orthogonal multiple access (AF-NOMA) networks and amplify-and-forward orthogonal multiple access (AF-OMA) networks in the presence of an eavesdropper.
2) It derives an upper bound expression for the strictly positive secrecy capacity (SPSC) of the AF-NOMA network, which represents the probability that the instantaneous secrecy rates are positive.
3) The analysis shows that the SPSC of NOMA is significantly lower than OMA due to the channel characterization of NOMA, but it can be improved by optimizing the power allocation coefficients.
Outage performance analysis of non-orthogonal multiple access systems with RF...IJECEIAES
Non-orthogonal multiple access (NOMA) has drawn enormous attention from the research community as a promising technology for future wireless communications with increasing demands of capacity and throughput. Especially, in the light of fifth-generation (5G) communication where multiple internet-of-things (IoT) devices are connected, the application of NOMA to indoor wireless networks has become more interesting to study. In view of this, we investigate the NOMA technique in energy harvesting (EH) half-duplex (HD) decode-and-forward (DF) power-splitting relaying (PSR) networks over indoor scenarios which are characterized by log-normal fading channels. The system performance of such networks is evaluated in terms of outage probability (OP) and total throughput for delay-limited transmission mode whose expressions are derived herein. In general, we can see in details how different system parameters affect such networks thanks to the results from Monte Carlo simulations. For illustrating the accuracy of our analytical results, we plot them along with the theoretical ones for comparison.
Joint Fixed Power Allocation and Partial Relay Selection Schemes for Cooperat...TELKOMNIKA JOURNAL
In the future wireless systems, non-orthogonal multiple-access (NOMA) with partial relay selection scheme is considered as developing research topic. In this paper, dual-hop relaying systems is deployed for NOMA, in which the signals are communicated with the assistance of decode-and-forward (DF) scheme. This paper presents exact expressions for outage probability over independent Rayleigh fading channels, and two partial relay selection schemes are provided. Using analytical result and Monte-Carlo method, we introduce forwarding strategy selection for fixed user allocation and exactness of derived formula is checked. The presented simulations confirm the the advantage of such proposed NOMA, and the effectiveness of the proposed forwarding strategy.
Joint impacts of relaying scheme and wireless power transfer in multiple acce...journalBEEI
This paper considers ergodic capacity of energy harvesting (EH) based cellular networks. Such a network employs non-orthogonal multiple access (NOMA) together with relaying scheme to serve two far users. In this system model, relay is facilitated power splitting (PS) protocol to implement energy harvesting (EH). To examine capacity, expressions of signal to noise ratio (SNR) need be computed to achieve capacity. Power allocation factors are different for two users in such system and hence performance gap happens to distinguish requirements for separated users. It can be confirmed that the proposed paradigm exhibits maximal achievable capacity in some scenarios of setting parameters. To confirm exactness of the analytical expressions and show advantages of the proposed EH-NOMA, simulation results are performed in terms of ergodic capacity.
Implement of multiple access technique by wireless power transfer and relayin...journalBEEI
In this paper, we investigate non-orthogonal multiple access (NOMA) network relying on wireless power transfer to prolong lifetime. The base station (BS) sends common signals to the relay with two functions (energy harvesting (EH) and signal processing) to further serve two NOMA users in downlink. Performance gap exists since different power allocation factor assigned from power splitting protocol adopted at the relay and such relay employs both amplify-and-forward (AF) and decode-and-forward schemes. To provide performance metrics, we prove formulas of the outage probability which is a function of transmit signal to noise ratio. Simulation results indicate specific parameters to adjust system performance of two user in the considered EH-NOMA system. This finding is important recommendation to design EH-NOMA which shows particular outage performance at required target rates.
Performance enhancement of wireless sensor network by using non-orthogonal mu...nooriasukmaningtyas
In this paper, we investigate a relaying wireless sensor network (WSN) with
the non-orthogonal multiple access (NOMA) and sensor node selection
schemes over rayleigh fading. Precisely, the system consists of two sensor
clusters, a sink node, and an amplify-and-forward (AF) relay. These sensors
applying the NOMA and sensor node selection schemes transmit the sensing
data from the sensor clusters via the relay to the sink. We derived the
expressions of outage probability and throughput for two sensor nodes. We
also provide numerical results to examine the behavior of the system. Finally,
we verify the validity of our analysis by using the monte-carlo simulation.
Cooperative underlay cognitive radio assisted NOMA: secondary network improve...TELKOMNIKA JOURNAL
In this paper, a downlink scenario of a non-orthogonal multiple access (NOMA) scheme with power constraint via spectrum sensing is considered. Such network provides improved outage performance and new scheme of NOMA-based cognitive radio (CR-NOMA) network are introduced. The different power allocation factors are examined subject to performance gap among these secondary NOMA users. To evaluate system performance, the exact outage probability expressions of secondary users are derived. Finally, the dissimilar performance problem in term of secondary users is illustrated via simulation, in which a power allocation scheme and the threshold rates are considered as main impacts of varying system performance. The simulation results show that the performance of CR-NOMA network can be improved significantly.
Exploiting Outage Performance of Wireless Powered NOMATELKOMNIKA JOURNAL
Considering a dual-hop energy-harvesting (EH) non-orthogonal multiple access (NOMA) relaying system, this paper consider novel relaying protocols based on time power switching-based relaying (TPSR) architecture for amplify-and-forward modes. We introduce novel system model relaying network with impacts of energy harvesting fractions and derive analytical expressions for outage probability for the information transmission link. It confirmed that right selection of power allocation for NOMA to obtain optimal performance. Theoretical results show that, in comparison with the conventional solutions, the proposed model can achieve optimal throughput efficiency for sufficiently small threshold SNR with condition of controlling time switching fractions and power splitting fractions appropriately in TPSR protocol. We also explore impacts of transmission distances in each hop, transmission rate, the other key parameters of TPSR to outage performance for different channel models. Simulation results are presented to corroborate the proposed methodology.
Hybrid Time-power Switching Protocol of Energy Harvesting Bidirectional Relay...TELKOMNIKA JOURNAL
In this paper, we investigate system performance in term of throughput and ergodic capacity of the hybrid time-power switching protocol of energy harvesting bidirectional relaying network. In the first stage, the analytical expression of the system throughput and ergodic capacity of the model system is proposed and derived. In this analysis, both delay-limited and delay-tolerant transmission modes are presented and considered. After that, the effect of various system parameters on the proposed system is investigated and demonstrated by Monte-Carlo simulation. Finally, the results show that the analytical mathematical and simulated results match for all possible parameter values for both schemes.
Average Channel Capacity of Amplify-and-forward MIMO/FSO Systems Over Atmosph...IJECEIAES
In amplify-and-forward (AF) relay channel, when the direct link between source and destination terminals is deeply faded, the signal from the source terminal to the destination terminal propagates through the relay terminals, each of which relays a signal received from the previous terminal to the next terminal in series. This paper, we theoretically analyze the performance of multiple-input multiple-output (MIMO) AF free-space optical (FSO) systems. The AF-MIMO/FSO average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) is derived taking into account the atmospheric turbulence effects on the MIMO/FSO channel. They are modeled by log-normal and the gamma-gamma distributions for the cases of weak-to-strong turbulence conditions. We extract closed form mathematical expression for the evaluation of the ACC and we quantitatively discuss the influence of turbulence strength, link distance, different number of relay stations and different MIMO configurations on it.
Secure outage probability of cognitive radio network relying non-orthogonal m...journalBEEI
This paper studies the secondary network relying relay selection to transmit signal from the secondary source (base station) to two destinations. Especially, two destinations are required non-orthogonal multiple access (NOMA) scheme and it benefits to implementation of the Internet of Things (IoT) systems. However, eavesdropper over-hears signal related link from selected relay to destination. This paper measure secure performance via metric, namely secure outage probability (SOP). In particular, signal to noise ratio (SNR) criterion is used to evalute SOP to provide reliable transmission to the terminal node. Main results indicates that the considered scheme provides performance gap among two signals at destination. The exactness of derived expressions is confirmed via numerical simulation.
Outage and throughput performance of cognitive radio based power domain based...TELKOMNIKA JOURNAL
This paper considers power domain based multiple access (PDMA) in cognitive radio network to serve numerous users who intend to multiple access to core network. In particular, we investigate the effect of signal combination scheme equipped at PDMA end-users as existence of direct link and relay link. This system model using relay scheme provides performance improvement on the outage probability of two PDMA end-users. We first propose a simple scheme of fixed power allocation to PDMA users who exhibit performance gap and fairness. Inspired by PDMA strategy, we then find signal to noise ratio (SNR) to detect separated signal for each user. In addition, the exact expressions of outage probability are derived in assumption that receiver can cancel out the interference completely with successive interference cancellation (SIC). By exploiting theoretical and simulation results, both considered combination schemes (Maximal Ratio Combining (MRC) and Selection Combining (SC) can achieve improved performance of two PDMA users significantly.
Wireless power transfer enabled NOMA relay systems: two SIC modes and perform...TELKOMNIKA JOURNAL
In this study, we deploy design and performance analysis in new system model using a relaying
model, energy harvesting, and non-orthogonal multi-access (NOMA) network. It is called such topology as
wireless powered NOMA relaying (WPNR). In the proposed model, NOMA will be investigated in two
cases including single successive interference cancellation (SIC) and dual SIC. Moreover,
the simultaneous wireless information and power transfer (SWIPT) technology can be employed to feed
energy to relays who intend to serve far NOMA users. In particular, exact outage probability expressions
are provided to performance evaluation. The results from the simulations are used to demonstrate
the outage performance of the proposed model in comparison with the current models and to verify correct
of derived expressions.
Physical layer security in DF full-duplex relaying network: performance analysisnooriasukmaningtyas
In this letter, the system performance of the DF full-duplex (FD) relaying
communication network is investigated with physical layer security (PLS). In
this system model, the source (S) and the destination (D) communicate via a
helping relay (R) in the presence of the eavesdropper (E). From the system
model, we derive the closed-form expressions for intercept probability (IP)
and secrecy outage probability (SOP). For verifying the correctness of the
analytical analysis, the Monte Carlo simulation is conducted. In addition, the
influence of the main system parameter on the system performance is
investigated. Finally, the results show that the analytical and the simulation
values agree well with each other.
Enabling full-duplex in multiple access technique for 5G wireless networks ov...TELKOMNIKA JOURNAL
This document analyzes the performance of a two-user non-orthogonal multiple access (NOMA) network where one user is served directly by the base station and the other is served via an unmanned aerial vehicle (UAV) relay operating in full-duplex mode. It derives the exact outage probabilities of the two users under Rician fading channels. The analysis provides guidelines for designing UAV-enabled wireless networks using NOMA techniques. Key results include the outage probabilities accounting for interference at both the UAV relay and users under different self-interference conditions at the relay.
Its exploring the technique for spatially successive interference cancellation and superposition of transmission for upcoming radio communication 5G technology.
Performance of cluster-based cognitive multihop networks under joint impact o...TELKOMNIKA JOURNAL
In this paper, we evaluate outage probability (OP) of a cluster-based multi-hop protocol operating
on an underlay cognitive radio (CR) mode. The primary network consists of multiple independent
transmit/receive pairs, and the primary transmitters seriously cause co-channel interference (CCI) to the
secondary receivers. To improve the outage performance for the secondary network under the joint impact
of the CCI and hardware imperfection, we employ the best relay selection at each hop. Moreover, the
destination is equipped with multiple antennas and uses the selection combining (SC) technique to
enhance the reliability of the data transmission at the last hop. For performance evaluation, we first derive
an exact formula of OP for the primary network which is used to calculate the transmit power of the
secondary transmitters. Next, an exact closed-form expression of the end-to-end OP for the secondary
network is derived over Rayleigh fading channels. We then perform Monte-Carlo simulations to validate
the derivations. The results present that the CCI caused by the primary operations significantly impacts on
the outage performance of the secondary network.
COOPERATIVE COMMUNICATIONS COMBINATION DIVERSITY TECHNIQUES AND OPTIMAL POWER...ijaceeejournal
The main task of this article is to focus on the performance of cooperative MIMO relaying in terms of data rate and Power. Furthermore, compare these performances when using Maximum Ratio Combining (MRC) and equal gain combining (EGC).The average SNR improvement of MRC is typically about 5 dB better than with EGC and direct link.The preciseness of the derived closed form expression of optimum power allocation of the DF-based relaying system is demonstrated by simulation results.
Intercept probability analysis in DF time switching full-duplex relaying netw...TELKOMNIKA JOURNAL
In this research, we propose and investigate intercept probability analysis in DF time switching relaying full-duplex with impact of Co-channel interference at the eavesdropper. In the beginning stage, we present the DF time switching relaying full-duplex with the Impact of Co-channel interference at the eavesdropper. Furthermore, the closed-form expression of the intercept probability (IP) is analyzed and derived in connection with the primary system parameters. Finally, the Monte Carlo simulation is performed for verifying the correctness of the analytical section. From the research results, a novel solution and some recommendations can be proposed for the communication network in the near future.
Similar to Exact Outage Performance Analysis of Amplify-and-forward-aware Cooperative NOMA (20)
Amazon products reviews classification based on machine learning, deep learni...TELKOMNIKA JOURNAL
In recent times, the trend of online shopping through e-commerce stores and websites has grown to a huge extent. Whenever a product is purchased on an e-commerce platform, people leave their reviews about the product. These reviews are very helpful for the store owners and the product’s manufacturers for the betterment of their work process as well as product quality. An automated system is proposed in this work that operates on two datasets D1 and D2 obtained from Amazon. After certain preprocessing steps, N-gram and word embedding-based features are extracted using term frequency-inverse document frequency (TF-IDF), bag of words (BoW) and global vectors (GloVe), and Word2vec, respectively. Four machine learning (ML) models support vector machines (SVM), logistic regression (RF), logistic regression (LR), multinomial Naïve Bayes (MNB), two deep learning (DL) models convolutional neural network (CNN), long-short term memory (LSTM), and standalone bidirectional encoder representations (BERT) are used to classify reviews as either positive or negative. The results obtained by the standard ML, DL models and BERT are evaluated using certain performance evaluation measures. BERT turns out to be the best-performing model in the case of D1 with an accuracy of 90% on features derived by word embedding models while the CNN provides the best accuracy of 97% upon word embedding features in the case of D2. The proposed model shows better overall performance on D2 as compared to D1.
Design, simulation, and analysis of microstrip patch antenna for wireless app...TELKOMNIKA JOURNAL
In this study, a microstrip patch antenna that works at 3.6 GHz was built and tested to see how well it works. In this work, Rogers RT/Duroid 5880 has been used as the substrate material, with a dielectric permittivity of 2.2 and a thickness of 0.3451 mm; it serves as the base for the examined antenna. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. The goal of this study was to get a more extensive transmission capacity, a lower voltage standing wave ratio (VSWR), and a lower return loss, but the main goal was to get a higher gain, directivity, and efficiency. After simulation, the return loss, gain, directivity, bandwidth, and efficiency of the supplied antenna are found to be -17.626 dB, 9.671 dBi, 9.924 dBi, 0.2 GHz, and 97.45%, respectively. Besides, the recreation uncovered that the transfer speed side-lobe level at phi was much better than those of the earlier works, at -28.8 dB, respectively. Thus, it makes a solid contender for remote innovation and more robust communication.
Design and simulation an optimal enhanced PI controller for congestion avoida...TELKOMNIKA JOURNAL
This document describes using a snake optimization algorithm to tune the gains of an enhanced proportional-integral controller for congestion avoidance in a TCP/AQM system. The controller aims to maintain a stable and desired queue size without noise or transmission problems. A linearized model of the TCP/AQM system is presented. An enhanced PI controller combining nonlinear gain and original PI gains is proposed. The snake optimization algorithm is then used to tune the parameters of the enhanced PI controller to achieve optimal system performance and response. Simulation results are discussed showing the proposed controller provides a stable and robust behavior for congestion control.
Improving the detection of intrusion in vehicular ad-hoc networks with modifi...TELKOMNIKA JOURNAL
Vehicular ad-hoc networks (VANETs) are wireless-equipped vehicles that form networks along the road. The security of this network has been a major challenge. The identity-based cryptosystem (IBC) previously used to secure the networks suffers from membership authentication security features. This paper focuses on improving the detection of intruders in VANETs with a modified identity-based cryptosystem (MIBC). The MIBC is developed using a non-singular elliptic curve with Lagrange interpolation. The public key of vehicles and roadside units on the network are derived from number plates and location identification numbers, respectively. Pseudo-identities are used to mask the real identity of users to preserve their privacy. The membership authentication mechanism ensures that only valid and authenticated members of the network are allowed to join the network. The performance of the MIBC is evaluated using intrusion detection ratio (IDR) and computation time (CT) and then validated with the existing IBC. The result obtained shows that the MIBC recorded an IDR of 99.3% against 94.3% obtained for the existing identity-based cryptosystem (EIBC) for 140 unregistered vehicles attempting to intrude on the network. The MIBC shows lower CT values of 1.17 ms against 1.70 ms for EIBC. The MIBC can be used to improve the security of VANETs.
Conceptual model of internet banking adoption with perceived risk and trust f...TELKOMNIKA JOURNAL
Understanding the primary factors of internet banking (IB) acceptance is critical for both banks and users; nevertheless, our knowledge of the role of users’ perceived risk and trust in IB adoption is limited. As a result, we develop a conceptual model by incorporating perceived risk and trust into the technology acceptance model (TAM) theory toward the IB. The proper research emphasized that the most essential component in explaining IB adoption behavior is behavioral intention to use IB adoption. TAM is helpful for figuring out how elements that affect IB adoption are connected to one another. According to previous literature on IB and the use of such technology in Iraq, one has to choose a theoretical foundation that may justify the acceptance of IB from the customer’s perspective. The conceptual model was therefore constructed using the TAM as a foundation. Furthermore, perceived risk and trust were added to the TAM dimensions as external factors. The key objective of this work was to extend the TAM to construct a conceptual model for IB adoption and to get sufficient theoretical support from the existing literature for the essential elements and their relationships in order to unearth new insights about factors responsible for IB adoption.
Efficient combined fuzzy logic and LMS algorithm for smart antennaTELKOMNIKA JOURNAL
The smart antennas are broadly used in wireless communication. The least mean square (LMS) algorithm is a procedure that is concerned in controlling the smart antenna pattern to accommodate specified requirements such as steering the beam toward the desired signal, in addition to placing the deep nulls in the direction of unwanted signals. The conventional LMS (C-LMS) has some drawbacks like slow convergence speed besides high steady state fluctuation error. To overcome these shortcomings, the present paper adopts an adaptive fuzzy control step size least mean square (FC-LMS) algorithm to adjust its step size. Computer simulation outcomes illustrate that the given model has fast convergence rate as well as low mean square error steady state.
Design and implementation of a LoRa-based system for warning of forest fireTELKOMNIKA JOURNAL
This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network that records environmental parameters such as temperature, humidity, wind speed, and carbon dioxide (CO2) concentration in the air, as well as taking infrared photos.The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected, processed, and uploaded to a cloud database at the gateway. An Android smartphone application that allows anyone to easily view the recorded data has been developed. When a fire is detected, the system will sound a siren and send a warning message to the responsible personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam, have been conducted to verify and evaluate the operation of the system.
Wavelet-based sensing technique in cognitive radio networkTELKOMNIKA JOURNAL
Cognitive radio is a smart radio that can change its transmitter parameter based on interaction with the environment in which it operates. The demand for frequency spectrum is growing due to a big data issue as many Internet of Things (IoT) devices are in the network. Based on previous research, most frequency spectrum was used, but some spectrums were not used, called spectrum hole. Energy detection is one of the spectrum sensing methods that has been frequently used since it is easy to use and does not require license users to have any prior signal understanding. But this technique is incapable of detecting at low signal-to-noise ratio (SNR) levels. Therefore, the wavelet-based sensing is proposed to overcome this issue and detect spectrum holes. The main objective of this work is to evaluate the performance of wavelet-based sensing and compare it with the energy detection technique. The findings show that the percentage of detection in wavelet-based sensing is 83% higher than energy detection performance. This result indicates that the wavelet-based sensing has higher precision in detection and the interference towards primary user can be decreased.
A novel compact dual-band bandstop filter with enhanced rejection bandsTELKOMNIKA JOURNAL
In this paper, we present the design of a new wide dual-band bandstop filter (DBBSF) using nonuniform transmission lines. The method used to design this filter is to replace conventional uniform transmission lines with nonuniform lines governed by a truncated Fourier series. Based on how impedances are profiled in the proposed DBBSF structure, the fractional bandwidths of the two 10 dB-down rejection bands are widened to 39.72% and 52.63%, respectively, and the physical size has been reduced compared to that of the filter with the uniform transmission lines. The results of the electromagnetic (EM) simulation support the obtained analytical response and show an improved frequency behavior.
Deep learning approach to DDoS attack with imbalanced data at the application...TELKOMNIKA JOURNAL
A distributed denial of service (DDoS) attack is where one or more computers attack or target a server computer, by flooding internet traffic to the server. As a result, the server cannot be accessed by legitimate users. A result of this attack causes enormous losses for a company because it can reduce the level of user trust, and reduce the company’s reputation to lose customers due to downtime. One of the services at the application layer that can be accessed by users is a web-based lightweight directory access protocol (LDAP) service that can provide safe and easy services to access directory applications. We used a deep learning approach to detect DDoS attacks on the CICDDoS 2019 dataset on a complex computer network at the application layer to get fast and accurate results for dealing with unbalanced data. Based on the results obtained, it is observed that DDoS attack detection using a deep learning approach on imbalanced data performs better when implemented using synthetic minority oversampling technique (SMOTE) method for binary classes. On the other hand, the proposed deep learning approach performs better for detecting DDoS attacks in multiclass when implemented using the adaptive synthetic (ADASYN) method.
The appearance of uncertainties and disturbances often effects the characteristics of either linear or nonlinear systems. Plus, the stabilization process may be deteriorated thus incurring a catastrophic effect to the system performance. As such, this manuscript addresses the concept of matching condition for the systems that are suffering from miss-match uncertainties and exogeneous disturbances. The perturbation towards the system at hand is assumed to be known and unbounded. To reach this outcome, uncertainties and their classifications are reviewed thoroughly. The structural matching condition is proposed and tabulated in the proposition 1. Two types of mathematical expressions are presented to distinguish the system with matched uncertainty and the system with miss-matched uncertainty. Lastly, two-dimensional numerical expressions are provided to practice the proposed proposition. The outcome shows that matching condition has the ability to change the system to a design-friendly model for asymptotic stabilization.
Implementation of FinFET technology based low power 4×4 Wallace tree multipli...TELKOMNIKA JOURNAL
Many systems, including digital signal processors, finite impulse response (FIR) filters, application-specific integrated circuits, and microprocessors, use multipliers. The demand for low power multipliers is gradually rising day by day in the current technological trend. In this study, we describe a 4×4 Wallace multiplier based on a carry select adder (CSA) that uses less power and has a better power delay product than existing multipliers. HSPICE tool at 16 nm technology is used to simulate the results. In comparison to the traditional CSA-based multiplier, which has a power consumption of 1.7 µW and power delay product (PDP) of 57.3 fJ, the results demonstrate that the Wallace multiplier design employing CSA with first zero finding logic (FZF) logic has the lowest power consumption of 1.4 µW and PDP of 27.5 fJ.
Evaluation of the weighted-overlap add model with massive MIMO in a 5G systemTELKOMNIKA JOURNAL
The flaw in 5G orthogonal frequency division multiplexing (OFDM) becomes apparent in high-speed situations. Because the doppler effect causes frequency shifts, the orthogonality of OFDM subcarriers is broken, lowering both their bit error rate (BER) and throughput output. As part of this research, we use a novel design that combines massive multiple input multiple output (MIMO) and weighted overlap and add (WOLA) to improve the performance of 5G systems. To determine which design is superior, throughput and BER are calculated for both the proposed design and OFDM. The results of the improved system show a massive improvement in performance ver the conventional system and significant improvements with massive MIMO, including the best throughput and BER. When compared to conventional systems, the improved system has a throughput that is around 22% higher and the best performance in terms of BER, but it still has around 25% less error than OFDM.
Reflector antenna design in different frequencies using frequency selective s...TELKOMNIKA JOURNAL
In this study, it is aimed to obtain two different asymmetric radiation patterns obtained from antennas in the shape of the cross-section of a parabolic reflector (fan blade type antennas) and antennas with cosecant-square radiation characteristics at two different frequencies from a single antenna. For this purpose, firstly, a fan blade type antenna design will be made, and then the reflective surface of this antenna will be completed to the shape of the reflective surface of the antenna with the cosecant-square radiation characteristic with the frequency selective surface designed to provide the characteristics suitable for the purpose. The frequency selective surface designed and it provides the perfect transmission as possible at 4 GHz operating frequency, while it will act as a band-quenching filter for electromagnetic waves at 5 GHz operating frequency and will be a reflective surface. Thanks to this frequency selective surface to be used as a reflective surface in the antenna, a fan blade type radiation characteristic at 4 GHz operating frequency will be obtained, while a cosecant-square radiation characteristic at 5 GHz operating frequency will be obtained.
Reagentless iron detection in water based on unclad fiber optical sensorTELKOMNIKA JOURNAL
A simple and low-cost fiber based optical sensor for iron detection is demonstrated in this paper. The sensor head consist of an unclad optical fiber with the unclad length of 1 cm and it has a straight structure. Results obtained shows a linear relationship between the output light intensity and iron concentration, illustrating the functionality of this iron optical sensor. Based on the experimental results, the sensitivity and linearity are achieved at 0.0328/ppm and 0.9824 respectively at the wavelength of 690 nm. With the same wavelength, other performance parameters are also studied. Resolution and limit of detection (LOD) are found to be 0.3049 ppm and 0.0755 ppm correspondingly. This iron sensor is advantageous in that it does not require any reagent for detection, enabling it to be simpler and cost-effective in the implementation of the iron sensing.
Impact of CuS counter electrode calcination temperature on quantum dot sensit...TELKOMNIKA JOURNAL
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
A progressive learning for structural tolerance online sequential extreme lea...TELKOMNIKA JOURNAL
This article discusses the progressive learning for structural tolerance online sequential extreme learning machine (PSTOS-ELM). PSTOS-ELM can save robust accuracy while updating the new data and the new class data on the online training situation. The robustness accuracy arises from using the householder block exact QR decomposition recursive least squares (HBQRD-RLS) of the PSTOS-ELM. This method is suitable for applications that have data streaming and often have new class data. Our experiment compares the PSTOS-ELM accuracy and accuracy robustness while data is updating with the batch-extreme learning machine (ELM) and structural tolerance online sequential extreme learning machine (STOS-ELM) that both must retrain the data in a new class data case. The experimental results show that PSTOS-ELM has accuracy and robustness comparable to ELM and STOS-ELM while also can update new class data immediately.
Electroencephalography-based brain-computer interface using neural networksTELKOMNIKA JOURNAL
This study aimed to develop a brain-computer interface that can control an electric wheelchair using electroencephalography (EEG) signals. First, we used the Mind Wave Mobile 2 device to capture raw EEG signals from the surface of the scalp. The signals were transformed into the frequency domain using fast Fourier transform (FFT) and filtered to monitor changes in attention and relaxation. Next, we performed time and frequency domain analyses to identify features for five eye gestures: opened, closed, blink per second, double blink, and lookup. The base state was the opened-eyes gesture, and we compared the features of the remaining four action gestures to the base state to identify potential gestures. We then built a multilayer neural network to classify these features into five signals that control the wheelchair’s movement. Finally, we designed an experimental wheelchair system to test the effectiveness of the proposed approach. The results demonstrate that the EEG classification was highly accurate and computationally efficient. Moreover, the average performance of the brain-controlled wheelchair system was over 75% across different individuals, which suggests the feasibility of this approach.
Adaptive segmentation algorithm based on level set model in medical imagingTELKOMNIKA JOURNAL
For image segmentation, level set models are frequently employed. It offer best solution to overcome the main limitations of deformable parametric models. However, the challenge when applying those models in medical images stills deal with removing blurs in image edges which directly affects the edge indicator function, leads to not adaptively segmenting images and causes a wrong analysis of pathologies wich prevents to conclude a correct diagnosis. To overcome such issues, an effective process is suggested by simultaneously modelling and solving systems’ two-dimensional partial differential equations (PDE). The first PDE equation allows restoration using Euler’s equation similar to an anisotropic smoothing based on a regularized Perona and Malik filter that eliminates noise while preserving edge information in accordance with detected contours in the second equation that segments the image based on the first equation solutions. This approach allows developing a new algorithm which overcome the studied model drawbacks. Results of the proposed method give clear segments that can be applied to any application. Experiments on many medical images in particular blurry images with high information losses, demonstrate that the developed approach produces superior segmentation results in terms of quantity and quality compared to other models already presented in previeous works.
Automatic channel selection using shuffled frog leaping algorithm for EEG bas...TELKOMNIKA JOURNAL
Drug addiction is a complex neurobiological disorder that necessitates comprehensive treatment of both the body and mind. It is categorized as a brain disorder due to its impact on the brain. Various methods such as electroencephalography (EEG), functional magnetic resonance imaging (FMRI), and magnetoencephalography (MEG) can capture brain activities and structures. EEG signals provide valuable insights into neurological disorders, including drug addiction. Accurate classification of drug addiction from EEG signals relies on appropriate features and channel selection. Choosing the right EEG channels is essential to reduce computational costs and mitigate the risk of overfitting associated with using all available channels. To address the challenge of optimal channel selection in addiction detection from EEG signals, this work employs the shuffled frog leaping algorithm (SFLA). SFLA facilitates the selection of appropriate channels, leading to improved accuracy. Wavelet features extracted from the selected input channel signals are then analyzed using various machine learning classifiers to detect addiction. Experimental results indicate that after selecting features from the appropriate channels, classification accuracy significantly increased across all classifiers. Particularly, the multi-layer perceptron (MLP) classifier combined with SFLA demonstrated a remarkable accuracy improvement of 15.78% while reducing time complexity.
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Prediction of Electrical Energy Efficiency Using Information on Consumer's Ac...PriyankaKilaniya
Energy efficiency has been important since the latter part of the last century. The main object of this survey is to determine the energy efficiency knowledge among consumers. Two separate districts in Bangladesh are selected to conduct the survey on households and showrooms about the energy and seller also. The survey uses the data to find some regression equations from which it is easy to predict energy efficiency knowledge. The data is analyzed and calculated based on five important criteria. The initial target was to find some factors that help predict a person's energy efficiency knowledge. From the survey, it is found that the energy efficiency awareness among the people of our country is very low. Relationships between household energy use behaviors are estimated using a unique dataset of about 40 households and 20 showrooms in Bangladesh's Chapainawabganj and Bagerhat districts. Knowledge of energy consumption and energy efficiency technology options is found to be associated with household use of energy conservation practices. Household characteristics also influence household energy use behavior. Younger household cohorts are more likely to adopt energy-efficient technologies and energy conservation practices and place primary importance on energy saving for environmental reasons. Education also influences attitudes toward energy conservation in Bangladesh. Low-education households indicate they primarily save electricity for the environment while high-education households indicate they are motivated by environmental concerns.
Software Engineering and Project Management - Software Testing + Agile Method...Prakhyath Rai
Software Testing: A Strategic Approach to Software Testing, Strategic Issues, Test Strategies for Conventional Software, Test Strategies for Object -Oriented Software, Validation Testing, System Testing, The Art of Debugging.
Agile Methodology: Before Agile – Waterfall, Agile Development.
Rainfall intensity duration frequency curve statistical analysis and modeling...bijceesjournal
Using data from 41 years in Patna’ India’ the study’s goal is to analyze the trends of how often it rains on a weekly, seasonal, and annual basis (1981−2020). First, utilizing the intensity-duration-frequency (IDF) curve and the relationship by statistically analyzing rainfall’ the historical rainfall data set for Patna’ India’ during a 41 year period (1981−2020), was evaluated for its quality. Changes in the hydrologic cycle as a result of increased greenhouse gas emissions are expected to induce variations in the intensity, length, and frequency of precipitation events. One strategy to lessen vulnerability is to quantify probable changes and adapt to them. Techniques such as log-normal, normal, and Gumbel are used (EV-I). Distributions were created with durations of 1, 2, 3, 6, and 24 h and return times of 2, 5, 10, 25, and 100 years. There were also mathematical correlations discovered between rainfall and recurrence interval.
Findings: Based on findings, the Gumbel approach produced the highest intensity values, whereas the other approaches produced values that were close to each other. The data indicates that 461.9 mm of rain fell during the monsoon season’s 301st week. However, it was found that the 29th week had the greatest average rainfall, 92.6 mm. With 952.6 mm on average, the monsoon season saw the highest rainfall. Calculations revealed that the yearly rainfall averaged 1171.1 mm. Using Weibull’s method, the study was subsequently expanded to examine rainfall distribution at different recurrence intervals of 2, 5, 10, and 25 years. Rainfall and recurrence interval mathematical correlations were also developed. Further regression analysis revealed that short wave irrigation, wind direction, wind speed, pressure, relative humidity, and temperature all had a substantial influence on rainfall.
Originality and value: The results of the rainfall IDF curves can provide useful information to policymakers in making appropriate decisions in managing and minimizing floods in the study area.
AI for Legal Research with applications, toolsmahaffeycheryld
AI applications in legal research include rapid document analysis, case law review, and statute interpretation. AI-powered tools can sift through vast legal databases to find relevant precedents and citations, enhancing research accuracy and speed. They assist in legal writing by drafting and proofreading documents. Predictive analytics help foresee case outcomes based on historical data, aiding in strategic decision-making. AI also automates routine tasks like contract review and due diligence, freeing up lawyers to focus on complex legal issues. These applications make legal research more efficient, cost-effective, and accessible.
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELijaia
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Software Engineering and Project Management - Introduction, Modeling Concepts...Prakhyath Rai
Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
as Design technique: Modeling, abstraction, The Three models. Class Modeling: Object and Class Concept, Link and associations concepts, Generalization and Inheritance, A sample class model, Navigation of class models, and UML diagrams
Building the Analysis Models: Requirement Analysis, Analysis Model Approaches, Data modeling Concepts, Object Oriented Analysis, Scenario-Based Modeling, Flow-Oriented Modeling, class Based Modeling, Creating a Behavioral Model.
Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
2. TELKOMNIKA ISSN: 1693-6930
Exact Outage Performance Analysis of Amplify-.... (Dinh-Thuan Do)
1967
strong users in NOMA can be forward signal to the weak users’ messages in the second time
slot in case of using half-duplex (HD) scheme and other relaying networks [15-17] can be
depoyed in NOMA. Motivated by above analysis in [9], this paper presents a fixed power
allocation scheme to show outage performance of separated users in the NOMA scheme in
case of AF scheme is deployed.
2. System model and Outage performance analysis
2.1. System model
We consider a downlink cooperative NOMA scenario consisting of one base station
denoted as BS, one relay R and twi users (i.e., the nearby user D2 and far user D1). The
Amplify-and-Forward (AF) protocol is employed at each relay and only one relay is selected to
assist BS conveying the information to the NOMAusers in each time slot. All wireless channels
in the considered scenario are assumed to be independent non-selective block Rayleigh fading
and are disturbed by additive white Gaussian noise with mean power 2
. The wireless channel
1 2(0,1), (0,1), (0,1),h CN g CN g CN denote the complex channel coefficient of BS-R, R-D1,
R-D2, respectively. In principle of NOMA, two users are classified into the nearby user and far
user by their quality of service (QoS) not sorted by their channel conditions. In this case, we
assume transmit power at relay and the BS is the same. System model of AF-NOMA as shown
in Figure 1.
Figure 1. System model of AF-NOMA
Based on the aforementioned assumptions, the observation at the relay R is given by
1 1 2 2R ry h a Px a Px w (1)
where ,r dw w are additive white Gaussian noise terms with variance 2
, 1 2,x x are the
normalized signal for D1, D2, respectively. It is assumed that 2 2
1 2 1E x E x , 1 2,a a are
power allocation factors. To stipulate better fairness between the users, we assume that 1 2a a
satisfying 1 2 1a a . Using AF scheme, the amplify gain is defined by
2 2
1
P h
(2)
In the second phase, the received signal at user D1 is
1 1 1 1 2 2 ,D r dy Pg h a Px a Px w w
(3)
Similarly, the received signal at user D2 is given by
3. ISSN: 1693-6930
TELKOMNIKA Vol. 16, No. 5, October 2018: 1966-1973
1968
2 2 1 1 2 2 2D r dy Pg a Px a Px h Pg w w (4)
To evaluate system performance, we first consider the received signal to interference and noise
ratio (SINR) at D1 to detect 1x is given by
22
1 1
1
2 22
1 2 1
2
2 2 1
a h g
h g a h g
(5)
In which, we denote 2
P
as signal to noise ratio (SNR) at the BS. By considering in SIC is
also invoked by D2 and the received SINR at D2 to detect 1x is given by
2 22
1 2
2, 1 2 2 2 22
2 2 2 1
x
a h g
h g a h g
(6)
Then the received SINR at D2 to detect its own information is given by
2 22
2 2
2, 2 2 2
2 1
x
a h g
h g
(7)
Remark 1: With regard to optimizing of power allocation can be studied to obtain better
performance as further work considered in our next papers. However, such computation of
power allocation needs more complexity in signal processing as overhead information of power
allocation must be known to control power associated with each users.
2.2. Outage performance analysis
In this section, we perform analysis on the performance of AF-NOMA scheme in terms
of outage probability for several signal processing cases. To make its convenient in analysis,
this paper presents exact expressions for the outage probability. In order to reduce the
computation complexity, a tight lower bound for the outage probability is provided in the high-
SNR regime to better understand the behavior of the network.
In general, an outage event occurs at the strong or the weak user when the user fails to
decode its own signal. In this section, we denote the threshold SNR as , 1,2i i . Based on the
rate requirements of the users, we can choose different values for R1 and R2, and we will
demonstrate how the R1 and R2 affect the outage performance in the numerical result section.
For sake of brevity, we denote 1 22 2
1 22 1, 2 1R R
e e= - = - .
2.2.1 The outage probability for detecting x1 at D1
We first consider the outage probability for detecting x1 at D1 can be expressed as
1 1, 1 1 1PrD xOP OP (8)
Next, it can be calculated each component of outage event as below
22
1 1
1, 1 1
2 22
1 2 1
2 2 2 2 22 2
1 1 1 1 2 1 1
2 2 2
1 1 2 1 1 1
2
Pr
2 2 1
2Pr 1
Pr 1
D x
a h g
OP
h g a h g
a h g h g a g h
g h a a h
(9)
4. TELKOMNIKA ISSN: 1693-6930
Exact Outage Performance Analysis of Amplify-.... (Dinh-Thuan Do)
1969
In the event of
2
1 2 1 1 0h a a , i.e.
2 1
1 2 1
h
a a
, we have 1, 1 0D xOP , else
1
1 2 1
2
1
1, 1 1 2
1 2 1 1
1
1 2 1 1
1
1
1 2 1 1
1 2 1 1 2 10
1
2Pr
1
exp
1
1
exp
D x
a a
h
OP g
h a a
z
z dz
z a a
t
a a t
dt
a a t a a
(10)
It is obtained (10) by putting new variable as
1
1 2 1 1
1 2 1
t
t
z a a z
a a
It can be
further manipulated as below
2
1 1 1 2 11
1, 1
1 2 1 1 2 1 1 2 1 1 2 10
21
exp expD x
a a t
OP dt
a a a a t a a a a
(11)
In final step, it can be expressed the outage event as below
1
1 2 1
2
1 1 1 2 1 1 1 1 2 1
1, 1 12 22 2
1 2 1 1 2 1
2 2
a a
D x
a a a a
OP e
a a a a
(12)
2.2.2 The outage probability for detecting x2 at D2
Secondly, the outage probability for detecting x2 at D2 can be expressed as
2 2, 2 2, 1 1 2, 2 2Pr ,D x x xOP OP (13)
Based on (6) and (7) and (12) we can find that:
2 22 2
1 2 2 2
2, 2 1 2
2 2 22
2 2 2
2 2
Pr ,
2 2 21 1
D x
a h g a h g
OP
h g a h g h g
(14)
In this paper, we approximate the
22
1 2 1
2, 1
2 22
2
2 2
2
2 2 1
x
a h g a
ah g a h g
in high SNR
regime when 2
1 . Therefore, it can be reduced as
22
2 21
2, 2 1 2
2
2
2
22
2 21
1 2
2
2
2
2
Pr ,
2 1
2
Pr Pr
2 1
D x
a h ga
OP
a h g
a h ga
a h g
(15)
5. ISSN: 1693-6930
TELKOMNIKA Vol. 16, No. 5, October 2018: 1966-1973
1970
Firstly, we consider the first item, if 1
1
2
a
a
we obtain 2, 2 0D xOP , else 1
1
2
a
a
we have
2 22
2 2
2, 2 2
2
2
2 2 2 22 2
2 2 2 2
2
22
2 2
2 2
Pr
2 1
Pr 1
1
Pr
D x
a h g
OP
h g
a h g h g
h
g
a h
(16)
Similarly, in the first case of 2
2 2 0a h , it leads to following equation
2 2
2
h
a
, outage
probability in this case calculated as 2, 2 0D xOP . In the second case, as 2
2 2 0a h
2
2
2
2, 2
2 2
1
expD x
a
z
OP z dz
a z
(17)
Similarly, it can be found outage probability in such as as
2 2 2 2 2
2, 2 12 2
2 2 22 2
2
exp 2 1 2 1D xOP
a a aa a
(18)
2.3 Outage performance at high SNR and The throughput on the outage probability
And the lower bounds of the outage probability in (11) and (17) are shown to be tight
bounds in the medium-and high-SNR regimes. At high SNR, the outage probability at D1 will
become
1
1 1 2
2
1, 1
a a
D xOP e
(19)
At high SNR, the outage probability at D2 will become
2
2
2
2, 2
a
D xOP e
The throughput mainly depends on the outage probability. The throughput at D1 will become
1
1 2 1
1 1
2
1 1 1 2 1 1 1 1 2 1
12 22 2
1 2 1 1 2 1
1
1 2 2
a a
OP R
a a a a
e R
a a a a
(20)
Similarly, the throughput at D2 will become
6. TELKOMNIKA ISSN: 1693-6930
Exact Outage Performance Analysis of Amplify-.... (Dinh-Thuan Do)
1971
2 2
2 2 2 2 2
12 2
2 2 22 2
1
2
1 exp 2 1 2 1
OP R
R
a a aa a
(21)
3. Simulation results
In this section, the outage performance of the downlink AF-NOMA network under
Rayleigh fading channel is evaluated via numerical examples to validate derived formula.
Moreover, the fixed power allocation is applied in order to further evaluation of such NOMA.
Without loss of generality, we assume the distance in each link of two-hop relaying NOMA is
normalized to unity. In the following simulations, we set 1 20.9, 0.1a a . We denote “ana” as
analysis and “sim” as Monte-Carlo simulation results.
Figure 2 plots the outage probability of considered scheme versus SNR for a simulation
setting 1 1R (bits/s/Hz), 2 1R (bits/s/Hz). It can be seen that the exact analytical results and
simulation results are matched very well. In particular, it shown that as the system SNR
increases, the outage probability decreases. Another important observation is that the outage
probability for User D1 of NOMA outperforms for User D2. Note that the results related to such
outage performance resulted from power allocation for each user in NOMA.
Figure 2. Outage probability vs. the transmit SNR
In Figure 3, the outage probability versus system SNR is presented in different
threshold SNR parameters. Three cases of target rates are set as 1 2, 1,2R R bits/s/Hz,
1 2, 0.5,1.5R R (bits/s/Hz). Obviously in this case, the outage probability curves match exactly
with the Monte Carlo simulation results. One can observe that adjusting the target rates of
NOMA users will affect the outage behaviors of considered scheme. As the value of target rates
increases, the outage performance will becomes worse. It is worth noting that the setting of
reasonable threshold SNR or target rate for NOMA users is prerequisite based on the specific
application requirements of different scenarios.
Figure 4 plots system outage probability versus SNR in high SNR mode. It can be
observed that the analytical results meet with that in high SNR case. In Figure 4, the outage
performance comparison in high SNR regime, where 1 1R (bits/s/Hz), 2 1R (bits/s/Hz). This
illustration indicates that our derived expressions are tight result for evaluation in related NOMA
networks.
Figure 5 plots system throughput versus SNR in delay-limited transmission mode.
Furthermore, the AF-based NOMA scheme for D1 outperform D2 in terms of system throughput.
Our setup is 1 1R (bits/s/Hz), 2 2R (bits/s/Hz). This phenomenon indicates that it is of
7. ISSN: 1693-6930
TELKOMNIKA Vol. 16, No. 5, October 2018: 1966-1973
1972
significance to consider the impact of power allocation for such scheme when designing
practical cooperative NOMA systems.
Figure 3. Outage probability vs. the transmit SNR with different threshold SNR
Figure 4. Outage performance comparison in high SNR regime
Figure 5. Throughput performance vs. the transmit SNR
8. TELKOMNIKA ISSN: 1693-6930
Exact Outage Performance Analysis of Amplify-.... (Dinh-Thuan Do)
1973
4. Conclusion
This paper presented a novel downlink cooperative communication system that
combines NOMA with AF relaying techniques in analytical model for outage analysis. The
proposed scheme achieves outage performance comparision under impacts of various
parameters in cooperative NOMA systems. Furthermore, impact of the transmit SNR of the
source node in cooperative relaying NOMA on the throughput is performed via simulation and
acceptable threshold can be shown to the system evaluation. The superior performance of the
proposed schemes was demonstrated by the numerical results. As a future work, it will be
interesting to investigate the user fairness problem only with relative locations of the users as in
group. More importantly, the outage probability of both strong and weak users in the system is
derived and verified by comparing numerical simulations and analytical simulation.
Acknowledgement
This research is funded by Foundation for Science and Technology Development of
Ton Duc Thang University (FOSTECT), website: http://fostect.tdt.edu.vn, under Grant
FOSTECT.2017.BR.21
References
[1] Y Saito et al. Non-orthogonal multiple access (NOMA) for cellular future radio access. Proc. IEEE
Veh. Tech. Conf, Dresden, Germany, 2013: 1-5.
[2] Islam S M R, Avazov N, Dobre O A, et al. Power-domain non-orthogonal multiple access (NOMA) in
5G systems: potentials and challenges. IEEE Communications Surveys Tutorials, 2016;(99): 1-1.
[3] Ding, Z, Yang, Z, Fan, P, HV, Poor. On the performance of nonorthogonal multiple access in 5G
systems with randomly deployed users. IEEE Signal Processing Letters, 2014; 21(12): 1501-1505.
[4] Timotheou, S, Krikidis, I. Fairness for non-orthogonal multiple access in 5G systems. IEEE Signal
Processing Letters, 2015; 22(10): 1647-1651.
[5] Y Liu, Z Ding, M Elkashlan, J Yuan. Nonorthogonal multiple access in large-scale underlay cognitive
radio networks. IEEE Trans. Veh.Technol, 2016; 65(12): 10152-10157.
[6] Dinh-Thuan Do, H-S Nguyen. A Tractable Approach to Analyze the Energy-Aware Two-way Relaying
Networks in Presence of Co-channel Interference. EURASIP Journal on Wireless Communications
and Networking, 2016:271.
[7] H-S Nguyen, A-H. Bui, Dinh-Thuan Do, M. Voznak. Imperfect Channel State Information of AF and
DF Energy Harvesting Cooperative Networks. China Communications, 2016; 13(10): 11-19.
[8] Dinh-Thuan Do. Power Switching Protocol for Two-way Relaying Network under Hardware
Impairments. Radioengineering, 2015; 24(3): 765-771.
[9] Z Ding, P Fan, H V Poor. Impact of user pairing on 5G non-orthogonal multiple-access downlink
transmissions. IEEE Trans. Veh.Technol., 2016; 65(8): 6010–6023.
[10] S Shi, L Yang, H Zhu. Outage balancing in downlink nonorthogonal multiple access with statistical
channel state information. IEEE Trans. Wireless Commun., 2016; 15(7): 4718-4731.
[11] P Xu, Y Yuan, Z Ding, X Dai, R Schober. On the outage performance of non-orthogonal multiple
access with 1-bit feedback. IEEE Trans. Wireless Commun., 2016; 15(10): 6716-6730.
[12] P D Diamantoulakis, K N Pappi, Z Ding, G K Karagiannidis. Wireless-powered communications with
non-orthogonal multiple access. IEEE Trans. Wireless Commun., 2016; 15(12): 8422-8436.
[13] X-X Nguyen, Dinh-Thuan Do. Maximum Harvested Energy Policy in Full-Duplex Relaying Networks
with SWIPT. International Journal of Communication Systems (Wiley), 2017; 30(17).
[14] T-L Nguyen, Dinh-Thuan Do. A new look at AF two-way relaying networks: energy harvesting
architecture and impact of co-channel interference. Annals of Telecommunications. 2017; 72(11):
669-678.
[15] S Arunmozhi, G Nagarajan. Performance of Full-Duplex One-Way and Two-Way Cooperative
Relaying Networks. Indonesian Journal of Electrical Engineering and Computer Science (IJEECS).
2018; 9(2): 526-538.
[16] D-T Do. Optimal Energy Har vesting Scheme for Power Beacon-Assisted Wireless-Powered
Networks. Indonesian Journal of Electrical Engineering and Computer Science (IJEECS). 2017; 7(3):
802-808.
[17] F Obite, K M Yusof, J Din. A Mathematical Approach for Hidden Node Problem in Cognitive Radio
Networks. Telkomnika, 2017; 15(3): 1127-1136.