Performance analysis for Adaptive Subcarriers Allocation in Coherent Optical ...iosrjce
The constraint to satisfy the need of increased bandwidth requirement for high speed applications
with higher performance has been a motivation to work on Optical Orthogonal Frequency division multiplexing
(OOFDM) technique with coherent detection. We implement the coherent optical OFDM (CO-OOFDM)
technique and investigate the effect of the number of sub-carriers on performance over single mode fiber (SMF)
links. To explore improvement in performance adaptive subcarriers has been selected by assigning subcarriers
to user according to the conditions of channel. An adaptive subcarrier allocation has been investigated and
performance comparison for proportional and equal allocation has been carried over.
Implementing packet broadcasting algorithm of mimo based mobile ad hoc networ...IJNSA Journal
With the rapid growth of wireless communication infras,,tructure over the recent few years, new
challenges has been posed on the system and analysis on wireless adhoc networking. Implementation of
MIMO communication in such type of network is enhancing the packet transmission capabilities. There
are different techniques for cooperative transmission and broadcasting packet in MIMO equipped
Mobile Adhoc Network. We have employed a model network in the OPNET environment and propose a
new scheduling algorithm based on investigating the different broadcasting algorithm. The new
broadcasting algorithm improves the packet transmission rate of the network based on energy
performance of the network and minimizes the BER for different transmission mode which is illustrated
in this paper. The simulations are done in MATLAB and OPNET environment and the simulated result
for the packet transmission rate are collected and shown in the tabular form. Also simulate the network
for generating a comparative statement for each mobile node. And performance analysis is also done for
the model network. The main focus is to minimize BER and improve information efficiency of the
network.
ZigBee has been developed to support lower data rates and low power consuming
applications. This paper targets to analyze various parameters of ZigBee physical (PHY).
Performance of ZigBee PHY is evaluated on the basis of energy consumption in
transmitting and receiving mode and throughput. Effect of variation in network size is
studied on these performance attributes. Some modulation schemes are also compared and
the best modulation scheme is suggested with tradeoffs between different performance
metrics.
MPR selection to the OLSR quality of service in MANET using minmax algorithmIJECEIAES
Optimized link state routing (OLSR) is a routing protocol that has a small delay, low traffic control, support the application of denser networks, and adopts the concept of multipoint relays (MPR). The problem of OLSR is routing table updating which continually causes excessive packet delivery, and energy consumption becomes increased. This article proposes the improvement of OLSR performance using the min-max algorithm based on the quality of service (QoS) with considering the density of the node. The Min-max algorithm works in selecting MPR nodes based on the largest signal range. The QoS parameters analyzed with a different number of nodes are packet delivery ratio (PDR), throughput, delay, energy consumption, and topology control (TC). Simulation result of network simulator version 2 (NS-2) shows that OLSR performance using the min-max algorithm can increase PDR of 91.17%, packet loss of 60.77% and reduce topology control packet of 8.07%, energy consumption of 16.82% compared with standard OLSR.
Performance analysis for Adaptive Subcarriers Allocation in Coherent Optical ...iosrjce
The constraint to satisfy the need of increased bandwidth requirement for high speed applications
with higher performance has been a motivation to work on Optical Orthogonal Frequency division multiplexing
(OOFDM) technique with coherent detection. We implement the coherent optical OFDM (CO-OOFDM)
technique and investigate the effect of the number of sub-carriers on performance over single mode fiber (SMF)
links. To explore improvement in performance adaptive subcarriers has been selected by assigning subcarriers
to user according to the conditions of channel. An adaptive subcarrier allocation has been investigated and
performance comparison for proportional and equal allocation has been carried over.
Implementing packet broadcasting algorithm of mimo based mobile ad hoc networ...IJNSA Journal
With the rapid growth of wireless communication infras,,tructure over the recent few years, new
challenges has been posed on the system and analysis on wireless adhoc networking. Implementation of
MIMO communication in such type of network is enhancing the packet transmission capabilities. There
are different techniques for cooperative transmission and broadcasting packet in MIMO equipped
Mobile Adhoc Network. We have employed a model network in the OPNET environment and propose a
new scheduling algorithm based on investigating the different broadcasting algorithm. The new
broadcasting algorithm improves the packet transmission rate of the network based on energy
performance of the network and minimizes the BER for different transmission mode which is illustrated
in this paper. The simulations are done in MATLAB and OPNET environment and the simulated result
for the packet transmission rate are collected and shown in the tabular form. Also simulate the network
for generating a comparative statement for each mobile node. And performance analysis is also done for
the model network. The main focus is to minimize BER and improve information efficiency of the
network.
ZigBee has been developed to support lower data rates and low power consuming
applications. This paper targets to analyze various parameters of ZigBee physical (PHY).
Performance of ZigBee PHY is evaluated on the basis of energy consumption in
transmitting and receiving mode and throughput. Effect of variation in network size is
studied on these performance attributes. Some modulation schemes are also compared and
the best modulation scheme is suggested with tradeoffs between different performance
metrics.
MPR selection to the OLSR quality of service in MANET using minmax algorithmIJECEIAES
Optimized link state routing (OLSR) is a routing protocol that has a small delay, low traffic control, support the application of denser networks, and adopts the concept of multipoint relays (MPR). The problem of OLSR is routing table updating which continually causes excessive packet delivery, and energy consumption becomes increased. This article proposes the improvement of OLSR performance using the min-max algorithm based on the quality of service (QoS) with considering the density of the node. The Min-max algorithm works in selecting MPR nodes based on the largest signal range. The QoS parameters analyzed with a different number of nodes are packet delivery ratio (PDR), throughput, delay, energy consumption, and topology control (TC). Simulation result of network simulator version 2 (NS-2) shows that OLSR performance using the min-max algorithm can increase PDR of 91.17%, packet loss of 60.77% and reduce topology control packet of 8.07%, energy consumption of 16.82% compared with standard OLSR.
A small vessel detection using a co-located multi-frequency FMCW MIMO radar IJECEIAES
Small vessels detection is a known issue due to its low radar cross section (RCS). An existing shore-based vessel tracking radar is for long-distance commercial vessels detection. Meanwhile, a vessel-mounted radar system known for its reliability has a limitation due to its single radar coverage. The paper presented a co-located frequency modulated continuous waveform (FMCW) maritime radar for small vessel detection utilising a multiple-input multiple-output (MIMO) configuration. The radar behaviour is numerically simulated for detecting a Swerling 1 target which resembles small maritime’s vessels. The simulated MIMO configuration comprised two transmitting and receiving nodes. The proposal is to utilize a multi-frequency FMCW MIMO configuration in a maritime environment by applying the spectrum averaging (SA) to fuse MIMO received signals for range and velocity estimation. The analysis was summarised and displayed in terms of estimation error performance, probability of error and average error. The simulation outcomes an improvement of 2.2 dB for a static target, and 0.1 dB for a moving target, in resulting the 20% probability of range error with the MIMO setup. A moving vessel's effect was observed to degrade the range error estimation performance between 0.6 to 2.7 dB. Meanwhile, the proposed method was proven to improve the 20% probability of velocity error by 1.75 dB. The impact of multi-frequency MIMO was also observed to produce better average error performance.
MMINIMUM RESOURCE CONSUMPTIONS ROUTING FOR OPTICAL NETWORKSprj_publication
The problem of determining primary and backup paths for survivable optical WDM
networks is considered. Results of various available routing techniques that try to minimize
the combined cost of primary and the backup path are analyzed for the effects on network
parameters such as mean load, variance of the load on route, number of converters required
by the route and the length of the route. The route cost is modelled such a way that it is
extensible to include any new parameter and vary their relative importance. The efficiency of
such wavelength routed networks has been proved to improve for certain parameters, such as
reduction in blocking probability and number of converters required for desired performance.
The routing is enhanced to analyse effect on network parameters for all node full range
converters, limited number full converters, reserved primary and back up wavelengths and
with no such reservation.
Mobility and Propagation Models in Multi-hop Cognitive Radio Networksszhb
Cognitive radio networks allow unlicensed
(secondary) users to opportunistically utilize the idle
resource of a licensed network for communication
without affecting the quality of service being offered to
the primary or licensed users. This paper investigates
the effect of mobility on performance of multi-hop
cognitive radio network under various propagation
models. MPEG4 video; a bandwidth intensive traffic, is
tested over these network conditions for secondary
users and results are validated using NS2 simulations.
Performance metrics used for evaluation include
throughput, delay variations etc.
A novel optimal small cells deployment for next-generation cellular networks IJECEIAES
Small-cell-deployments have pulled cellular operators to boost coverage and capacity in high-demand areas (for example, downtown hot spots). The location of these small cells (SCs) should be determined in order to achieve successful deployments. In this paper, we propose a new approach that optimizes small cells deployment in cellular networks to achieve three objectives: reduce the total cost of network installation, balancing the allocation of resources, i.e. placement of each SC and their transmitted power, and providing optimal coverage area with a lower amount of interference between adjacent stations. An accurate formula was obtained to determine the optimum number of SC deployment (NSC). Finally, we derive a mathematical expression to calculate the critical-handoff-point (CHP) for neighboring wireless stations.
Resource Allocation in MIMO – OFDM Communication System under Signal Strength...Kumar Goud
Abstract: - Multiple Inputs and Multiple Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) system have the potential to attain high capability on the propagation setting. The aim of this paper is that the adaptive resource allocation in MIMO-OFDM system uses the water filling formula. Water filling answer is enforced for allocating the ability so as to extend the data rate. The overall system capability is maximised subject to the constraints on total power, signal to noise quantitative relation, and proportionality. Channel is assumed as a flat attenuation channel and therefore the comparison is created for various 2×2, 2×3, 3×2 and 4×4 MIMO-OFDM systems and water filling formula with allotted power. Supported the capability contribution from the relaying terminal, a brand new parameter referred to as cooperation constant is introduced as an operate of the relaying sub channel. This parameter is employed to switch the target parameter of the subcarrier allocation procedure. Fairness-oriented [Fading Channel] and throughput-oriented [Near finish Channel] algorithms square measure elite from the literature to check the planned technique. Each algorithms square measure changed to use the mean of cooperation constant within the objective parameter of the subcarrier allocation procedure and shown to own a much better total turnout with none sacrifice.
Keywords - MIMO-OFDM; Water filling Algorithm; Subcarrier Resource Allocation
Efficient energy, cost reduction, and QoS based routing protocol for wireless...IJECEIAES
Recent developments and widespread in wireless sensor network have led to many routing protocols, many of these protocols consider the efficiency of energy as the ultimate factor to maximize the WSN lifetime. The quality of Service (QoS) requirements for different applications of wireless sensor networks has posed additional challenges. Imaging and data transmission needs both QoS aware routing and energy to ensure the efficient use of sensors. In this paper, we propose an Efficient, Energy-Aware, Least Cost, (ECQSR) quality of service routing protocol for sensor networks which can run efficiently with best-effort traffic processing. The protocol aims to maximize the lifetime of the network out of balancing energy consumption across multiple nodes, by using the concept of service differentiation, finding lower cost by finding the shortest path using nearest neighbor algorithm (NN), also put certain constraints on the delay of the path for real-time data from where link cost that captures energy nodes reserve, energy of the transmission, error rate and other parameters. The results show that the proposed protocol improves the network lifetime and low power consumption.
This paper presents the design and performance comparison of a two stage
operational amplifier topology using CMOS and BiCMOS technology. This conventional op
amp circuit was designed by using RF model of BSIM3V3 in 0.6 μm CMOS technology and
0.35 μm BiCMOS technology. Both the op amp circuits were designed and simulated,
analyzed and performance parameters are compared. The performance parameters such as
gain, phase margin, CMRR, PSRR, power consumption etc achieved are compared. Finally,
we conclude the suitability of CMOS technology over BiCMOS technology for low power
RF design.
Implementation of a bpsk modulation based cognitive radio system using the en...csandit
We present in this work an energy detection algorit
hm, based on spectral power estimation, in
the context of cognitive radio. The algorithm is ba
sed on the Neyman-Pearson test where the
robustness of the appropriate spectral bands identi
fication, is based, at one hand, on the
‘judicious’ choice of the probability of detection
(P
D
) and false alarm probability (P
F
). First, we
accomplish a comparative study between two techniqu
es for estimation of PSD (Power Spectral
Density): the periodogram and Welch methods. Also,
the interest is focused on the choice of the
optimal duration of observation where we can state
that this latter one should be inversely
proportional to the level of the SNR of the transmi
tted signal to be sensed. The developed
algorithm is applied in the context of cognitive ra
dio. The algorithm aims to identify the free
spectral bands representing, reserved for the prima
ry user, of the signal carrying information,
issued from an ASCII encoding alphanumeric message
and utilizing the BPSK modulation,
transmitted through an AWGN (Added White Gaussian N
oise) channel. The algorithm succeeds
in identifying the free spectral bands even for low
SNR levels (e.g. to -2 dB) and allocate them
to the informative signal representing the secondar
y user.
Massive multiple-input multiple-output (MIMO) systems are considered a promising solution to minimize multiuser interference (MUI) based on simple precoding techniques with a massive antenna array at a base station (BS). This paper presents a novel approach of beam division multiple access (BDMA) which BS transmit signals to multiusers at the same time via different beams based on hybrid beamforming and user-beam schedule. With the selection of users whose steering vectors are orthogonal to each other, interference between users is significantly improved. While, the efficiency spectrum of proposed scheme reaches to the performance of fully digital solutions, the multiuser interference is considerably reduced.
A NEW HYBRID DIVERSITY COMBINING SCHEME FOR MOBILE RADIO COMMUNICATION SYSTEM...ijcsit
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced system complexity.
techInvestigations with mode division multiplexed transmissionelelijjournal
This article presents proposed topology for mode division multiplexed link with SPDML and VCSEL, modulate electrical signal of 820nm wavelength. Transmission performance has been investigated for numerous modes, bit rates (2.5 to 10Gbps), transmission lengths of MMF (1 to 100km) and attenuation factor in conjunction with parabolic operational mode. Results illustrated successful performance up to nine modes in mode-division multiplexed transmission. Performance is improved at low data rates, illustrated higher OSNR with lower BER,-5dB attenuation factor. Though, at higher bit rate and longer
transmission length received OSNR is unsteady. It further inferred that transmission with large number of multiplexed modes result in degraded performance, augmented with minimization of mode coupling losses.Mode division multiplexed multimode optical communication can be a viable option for supplementary capacity augment in the preexisting and future fiber optic communication links.
Novel Position Estimation using Differential Timing Information for Asynchron...IJCNCJournal
Positioning techniques have been a common objective since the early development of wireless networks. However, current positioning methods in cellular networks, for instance, are still primarily focused on the use of the Global Navigation Satellite System (GNSS), which has several limitations, like high power drainage and failure in indoor scenarios. This study introduces a novel approach employing standard LTE signaling in order to provide high accuracy positioning estimation. The proposed technique is designed in analogy to the human sound localization system, eliminating the need of having information from three spatially diverse Base Stations (BSs). This is inspired by the perfect human 3D sound localization with two ears. A field study is carried out in a dense urban city to verify the accuracy of the proposed technique, with more than 20 thousand measurement samples collected. The achieved positioning accuracy is meeting the latest Federal Communications Commission (FCC) requirements in the planner dimension.
Mitigation of packet loss with end-to-end delay in wireless body area network...IJECEIAES
The wireless body area network (WBAN) has been proposed to offer a solution to the problem of population ageing, shortage in medical facilities and different chronic diseases. The development of this technology has been further fueled by the demand for real-time application for monitoring these cases in networks. The integrity of communication is constrained by the loss of packets during communication affecting the reliability of WBAN. Mitigating the loss of packets and ensuring the performance of the network is a challenging task that has sparked numerous studies over the years. The WBAN technology as a problem of reducing network lifetime; thus, in this paper, we utilize cooperative routing protocol (CRP) to improve package delivery via end-to-end latency and increase the length of the network lifetime. The end-to-end latency was used as a metric to determine the significance of CRP in WBAN routing protocols. The CRP increased the rate of transmission of packets to the sink and mitigate packet loss. The proposed solution has shown that the end-to-end delay in the WBAN is considerably reduced by applying the cooperative routing protocol. The CRP technique attained a delivery ratio of 0.8176 compared to 0.8118 when transmitting packets in WBAN.
Optimized Cluster Establishment and Cluster-Head Selection Approach in WSNIJCNCJournal
In recent years, limited resources of user products and energy-saving are recognized as the major challenges of Wireless Sensor Networks (WSNs). Clustering is a practical technique that can reduce all energy consumption and provide stability of workload that causes a larger difference in energy depletion among other nodes and cluster heads (CHs). In addition, clustering is the solution of energy-efficient for maximizing the network longevity and improvising energy efficiency. In this paper, a novel OCE-CHS (Optimized Cluster Establishment and Cluster-Head Selection) approach for sensor nodes is represented to improvise the packet success ratio and reduce the average energy-dissipation. The main contribution of this paper is categorized into two processes, first, the clustering algorithm is improvised that periodically chooses the optimal set of the CHs according to the speed of the average node and average-node energy. This is considerably distinguished from node-based clustering that utilizes a distributed clustering algorithm to choose CHs based on the speed of the current node and remaining node energy. Second, more than one factor is assumed for the detached node to join the optimal cluster. In the result section, we discuss our clustering protocols implementation of optimal CH-selection to evade the death of SNs, maximizing throughput, and further improvise the network lifetime by minimizing energy consumption.
An Efficient Performance of Mimo - Ofdm Based Cognitieve Radio System for Arr...IOSR Journals
Abstract: The wireless channel is central within this context, thus estimating the channel is the key to make CR operational, taking in consideration that the transmission-reception technology is available. In this thesis, we design a MIMO system using OFDM modulation technology to transmit and receive two signals over the mobile wireless channel. First formulate the pilot design as a new optimization problem. We use MIMO concept to enhance system capacity and robustness of the wireless transmission. In Multi-Input Multi-Output (MIMO) based cognitive radio (CR) systems, with the increasing demand for data rate and reliability in Wireless communicationsand devices, several issues become very important like bandwidth efficiency, quality of service and radio coverage. In this new scheme, adaptive arrays are group-selected in the spatial domain. Simulation shows that the proposed system can get significant performance improvements over the conventional array based OFDM systems over frequency-selective multipath fading channels with cognitive radio (CR) system. Keywords: Cognitive radios, MIMO, OFDM, and Joint transmit and receive group selected arrays.
An Approach to Improve the Quality of Service in OFDMA Relay Networks via Re-...iosrjce
With the next-generation cellular networks making a transition toward smaller cells, two-hop
orthogonal frequency-division multiple access (OFDMA) relay networks have become a dominant, mandatory
component in the 4G standards (WiMAX802.16j, 3GPP LTE-Adv.). Here we are using the multicasting strategy
Given the growing importance of multimedia broadcast and multicast services (MBMS) in 4G networks, the
latter forms the focus of this project. The main aim of this project is to improve the performance of the OFDMA
based relay networks. The OFDMA transmission Scheme is a widely accepted scheme for improving the quality
and speed of communication over the 4G cellular network. There are two different models designed for OFDMA
relay networks .Distributed (DP) and Contiguous (CP) permutations. We are checking the performance of two
algorithms The linear programming algorithm and the greedy algorithm by using two models of OFDMA for
multicast scheduling and after performance evaluation we select the best model and the algorithm for
transmission. We further improve the throughput via retransmission of lost packets during data transfer over the
specified network. We can detect the packet loss by packet synchronization technique and a request will be sent
by the destination for re-sending the lost packets which is called as Re-Transmission.[1]
A small vessel detection using a co-located multi-frequency FMCW MIMO radar IJECEIAES
Small vessels detection is a known issue due to its low radar cross section (RCS). An existing shore-based vessel tracking radar is for long-distance commercial vessels detection. Meanwhile, a vessel-mounted radar system known for its reliability has a limitation due to its single radar coverage. The paper presented a co-located frequency modulated continuous waveform (FMCW) maritime radar for small vessel detection utilising a multiple-input multiple-output (MIMO) configuration. The radar behaviour is numerically simulated for detecting a Swerling 1 target which resembles small maritime’s vessels. The simulated MIMO configuration comprised two transmitting and receiving nodes. The proposal is to utilize a multi-frequency FMCW MIMO configuration in a maritime environment by applying the spectrum averaging (SA) to fuse MIMO received signals for range and velocity estimation. The analysis was summarised and displayed in terms of estimation error performance, probability of error and average error. The simulation outcomes an improvement of 2.2 dB for a static target, and 0.1 dB for a moving target, in resulting the 20% probability of range error with the MIMO setup. A moving vessel's effect was observed to degrade the range error estimation performance between 0.6 to 2.7 dB. Meanwhile, the proposed method was proven to improve the 20% probability of velocity error by 1.75 dB. The impact of multi-frequency MIMO was also observed to produce better average error performance.
MMINIMUM RESOURCE CONSUMPTIONS ROUTING FOR OPTICAL NETWORKSprj_publication
The problem of determining primary and backup paths for survivable optical WDM
networks is considered. Results of various available routing techniques that try to minimize
the combined cost of primary and the backup path are analyzed for the effects on network
parameters such as mean load, variance of the load on route, number of converters required
by the route and the length of the route. The route cost is modelled such a way that it is
extensible to include any new parameter and vary their relative importance. The efficiency of
such wavelength routed networks has been proved to improve for certain parameters, such as
reduction in blocking probability and number of converters required for desired performance.
The routing is enhanced to analyse effect on network parameters for all node full range
converters, limited number full converters, reserved primary and back up wavelengths and
with no such reservation.
Mobility and Propagation Models in Multi-hop Cognitive Radio Networksszhb
Cognitive radio networks allow unlicensed
(secondary) users to opportunistically utilize the idle
resource of a licensed network for communication
without affecting the quality of service being offered to
the primary or licensed users. This paper investigates
the effect of mobility on performance of multi-hop
cognitive radio network under various propagation
models. MPEG4 video; a bandwidth intensive traffic, is
tested over these network conditions for secondary
users and results are validated using NS2 simulations.
Performance metrics used for evaluation include
throughput, delay variations etc.
A novel optimal small cells deployment for next-generation cellular networks IJECEIAES
Small-cell-deployments have pulled cellular operators to boost coverage and capacity in high-demand areas (for example, downtown hot spots). The location of these small cells (SCs) should be determined in order to achieve successful deployments. In this paper, we propose a new approach that optimizes small cells deployment in cellular networks to achieve three objectives: reduce the total cost of network installation, balancing the allocation of resources, i.e. placement of each SC and their transmitted power, and providing optimal coverage area with a lower amount of interference between adjacent stations. An accurate formula was obtained to determine the optimum number of SC deployment (NSC). Finally, we derive a mathematical expression to calculate the critical-handoff-point (CHP) for neighboring wireless stations.
Resource Allocation in MIMO – OFDM Communication System under Signal Strength...Kumar Goud
Abstract: - Multiple Inputs and Multiple Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) system have the potential to attain high capability on the propagation setting. The aim of this paper is that the adaptive resource allocation in MIMO-OFDM system uses the water filling formula. Water filling answer is enforced for allocating the ability so as to extend the data rate. The overall system capability is maximised subject to the constraints on total power, signal to noise quantitative relation, and proportionality. Channel is assumed as a flat attenuation channel and therefore the comparison is created for various 2×2, 2×3, 3×2 and 4×4 MIMO-OFDM systems and water filling formula with allotted power. Supported the capability contribution from the relaying terminal, a brand new parameter referred to as cooperation constant is introduced as an operate of the relaying sub channel. This parameter is employed to switch the target parameter of the subcarrier allocation procedure. Fairness-oriented [Fading Channel] and throughput-oriented [Near finish Channel] algorithms square measure elite from the literature to check the planned technique. Each algorithms square measure changed to use the mean of cooperation constant within the objective parameter of the subcarrier allocation procedure and shown to own a much better total turnout with none sacrifice.
Keywords - MIMO-OFDM; Water filling Algorithm; Subcarrier Resource Allocation
Efficient energy, cost reduction, and QoS based routing protocol for wireless...IJECEIAES
Recent developments and widespread in wireless sensor network have led to many routing protocols, many of these protocols consider the efficiency of energy as the ultimate factor to maximize the WSN lifetime. The quality of Service (QoS) requirements for different applications of wireless sensor networks has posed additional challenges. Imaging and data transmission needs both QoS aware routing and energy to ensure the efficient use of sensors. In this paper, we propose an Efficient, Energy-Aware, Least Cost, (ECQSR) quality of service routing protocol for sensor networks which can run efficiently with best-effort traffic processing. The protocol aims to maximize the lifetime of the network out of balancing energy consumption across multiple nodes, by using the concept of service differentiation, finding lower cost by finding the shortest path using nearest neighbor algorithm (NN), also put certain constraints on the delay of the path for real-time data from where link cost that captures energy nodes reserve, energy of the transmission, error rate and other parameters. The results show that the proposed protocol improves the network lifetime and low power consumption.
This paper presents the design and performance comparison of a two stage
operational amplifier topology using CMOS and BiCMOS technology. This conventional op
amp circuit was designed by using RF model of BSIM3V3 in 0.6 μm CMOS technology and
0.35 μm BiCMOS technology. Both the op amp circuits were designed and simulated,
analyzed and performance parameters are compared. The performance parameters such as
gain, phase margin, CMRR, PSRR, power consumption etc achieved are compared. Finally,
we conclude the suitability of CMOS technology over BiCMOS technology for low power
RF design.
Implementation of a bpsk modulation based cognitive radio system using the en...csandit
We present in this work an energy detection algorit
hm, based on spectral power estimation, in
the context of cognitive radio. The algorithm is ba
sed on the Neyman-Pearson test where the
robustness of the appropriate spectral bands identi
fication, is based, at one hand, on the
‘judicious’ choice of the probability of detection
(P
D
) and false alarm probability (P
F
). First, we
accomplish a comparative study between two techniqu
es for estimation of PSD (Power Spectral
Density): the periodogram and Welch methods. Also,
the interest is focused on the choice of the
optimal duration of observation where we can state
that this latter one should be inversely
proportional to the level of the SNR of the transmi
tted signal to be sensed. The developed
algorithm is applied in the context of cognitive ra
dio. The algorithm aims to identify the free
spectral bands representing, reserved for the prima
ry user, of the signal carrying information,
issued from an ASCII encoding alphanumeric message
and utilizing the BPSK modulation,
transmitted through an AWGN (Added White Gaussian N
oise) channel. The algorithm succeeds
in identifying the free spectral bands even for low
SNR levels (e.g. to -2 dB) and allocate them
to the informative signal representing the secondar
y user.
Massive multiple-input multiple-output (MIMO) systems are considered a promising solution to minimize multiuser interference (MUI) based on simple precoding techniques with a massive antenna array at a base station (BS). This paper presents a novel approach of beam division multiple access (BDMA) which BS transmit signals to multiusers at the same time via different beams based on hybrid beamforming and user-beam schedule. With the selection of users whose steering vectors are orthogonal to each other, interference between users is significantly improved. While, the efficiency spectrum of proposed scheme reaches to the performance of fully digital solutions, the multiuser interference is considerably reduced.
A NEW HYBRID DIVERSITY COMBINING SCHEME FOR MOBILE RADIO COMMUNICATION SYSTEM...ijcsit
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced system complexity.
techInvestigations with mode division multiplexed transmissionelelijjournal
This article presents proposed topology for mode division multiplexed link with SPDML and VCSEL, modulate electrical signal of 820nm wavelength. Transmission performance has been investigated for numerous modes, bit rates (2.5 to 10Gbps), transmission lengths of MMF (1 to 100km) and attenuation factor in conjunction with parabolic operational mode. Results illustrated successful performance up to nine modes in mode-division multiplexed transmission. Performance is improved at low data rates, illustrated higher OSNR with lower BER,-5dB attenuation factor. Though, at higher bit rate and longer
transmission length received OSNR is unsteady. It further inferred that transmission with large number of multiplexed modes result in degraded performance, augmented with minimization of mode coupling losses.Mode division multiplexed multimode optical communication can be a viable option for supplementary capacity augment in the preexisting and future fiber optic communication links.
Novel Position Estimation using Differential Timing Information for Asynchron...IJCNCJournal
Positioning techniques have been a common objective since the early development of wireless networks. However, current positioning methods in cellular networks, for instance, are still primarily focused on the use of the Global Navigation Satellite System (GNSS), which has several limitations, like high power drainage and failure in indoor scenarios. This study introduces a novel approach employing standard LTE signaling in order to provide high accuracy positioning estimation. The proposed technique is designed in analogy to the human sound localization system, eliminating the need of having information from three spatially diverse Base Stations (BSs). This is inspired by the perfect human 3D sound localization with two ears. A field study is carried out in a dense urban city to verify the accuracy of the proposed technique, with more than 20 thousand measurement samples collected. The achieved positioning accuracy is meeting the latest Federal Communications Commission (FCC) requirements in the planner dimension.
Mitigation of packet loss with end-to-end delay in wireless body area network...IJECEIAES
The wireless body area network (WBAN) has been proposed to offer a solution to the problem of population ageing, shortage in medical facilities and different chronic diseases. The development of this technology has been further fueled by the demand for real-time application for monitoring these cases in networks. The integrity of communication is constrained by the loss of packets during communication affecting the reliability of WBAN. Mitigating the loss of packets and ensuring the performance of the network is a challenging task that has sparked numerous studies over the years. The WBAN technology as a problem of reducing network lifetime; thus, in this paper, we utilize cooperative routing protocol (CRP) to improve package delivery via end-to-end latency and increase the length of the network lifetime. The end-to-end latency was used as a metric to determine the significance of CRP in WBAN routing protocols. The CRP increased the rate of transmission of packets to the sink and mitigate packet loss. The proposed solution has shown that the end-to-end delay in the WBAN is considerably reduced by applying the cooperative routing protocol. The CRP technique attained a delivery ratio of 0.8176 compared to 0.8118 when transmitting packets in WBAN.
Optimized Cluster Establishment and Cluster-Head Selection Approach in WSNIJCNCJournal
In recent years, limited resources of user products and energy-saving are recognized as the major challenges of Wireless Sensor Networks (WSNs). Clustering is a practical technique that can reduce all energy consumption and provide stability of workload that causes a larger difference in energy depletion among other nodes and cluster heads (CHs). In addition, clustering is the solution of energy-efficient for maximizing the network longevity and improvising energy efficiency. In this paper, a novel OCE-CHS (Optimized Cluster Establishment and Cluster-Head Selection) approach for sensor nodes is represented to improvise the packet success ratio and reduce the average energy-dissipation. The main contribution of this paper is categorized into two processes, first, the clustering algorithm is improvised that periodically chooses the optimal set of the CHs according to the speed of the average node and average-node energy. This is considerably distinguished from node-based clustering that utilizes a distributed clustering algorithm to choose CHs based on the speed of the current node and remaining node energy. Second, more than one factor is assumed for the detached node to join the optimal cluster. In the result section, we discuss our clustering protocols implementation of optimal CH-selection to evade the death of SNs, maximizing throughput, and further improvise the network lifetime by minimizing energy consumption.
An Efficient Performance of Mimo - Ofdm Based Cognitieve Radio System for Arr...IOSR Journals
Abstract: The wireless channel is central within this context, thus estimating the channel is the key to make CR operational, taking in consideration that the transmission-reception technology is available. In this thesis, we design a MIMO system using OFDM modulation technology to transmit and receive two signals over the mobile wireless channel. First formulate the pilot design as a new optimization problem. We use MIMO concept to enhance system capacity and robustness of the wireless transmission. In Multi-Input Multi-Output (MIMO) based cognitive radio (CR) systems, with the increasing demand for data rate and reliability in Wireless communicationsand devices, several issues become very important like bandwidth efficiency, quality of service and radio coverage. In this new scheme, adaptive arrays are group-selected in the spatial domain. Simulation shows that the proposed system can get significant performance improvements over the conventional array based OFDM systems over frequency-selective multipath fading channels with cognitive radio (CR) system. Keywords: Cognitive radios, MIMO, OFDM, and Joint transmit and receive group selected arrays.
An Approach to Improve the Quality of Service in OFDMA Relay Networks via Re-...iosrjce
With the next-generation cellular networks making a transition toward smaller cells, two-hop
orthogonal frequency-division multiple access (OFDMA) relay networks have become a dominant, mandatory
component in the 4G standards (WiMAX802.16j, 3GPP LTE-Adv.). Here we are using the multicasting strategy
Given the growing importance of multimedia broadcast and multicast services (MBMS) in 4G networks, the
latter forms the focus of this project. The main aim of this project is to improve the performance of the OFDMA
based relay networks. The OFDMA transmission Scheme is a widely accepted scheme for improving the quality
and speed of communication over the 4G cellular network. There are two different models designed for OFDMA
relay networks .Distributed (DP) and Contiguous (CP) permutations. We are checking the performance of two
algorithms The linear programming algorithm and the greedy algorithm by using two models of OFDMA for
multicast scheduling and after performance evaluation we select the best model and the algorithm for
transmission. We further improve the throughput via retransmission of lost packets during data transfer over the
specified network. We can detect the packet loss by packet synchronization technique and a request will be sent
by the destination for re-sending the lost packets which is called as Re-Transmission.[1]
PERFORMANCE OF MIMO MC-CDMA SYSTEM WITH CHANNEL ESTIMATION AND MMSE EQUALIZATIONTamilarasan N
The quality of a wireless link can be described by three basic parameters, namely transmission rate, transmission range
and transmission reliability. With the advent of multiple-input multiple-output (MIMO) assisted Multicarrier code
division multiple access (MC-CDMA) systems, the above-mentioned three parameters may be simultaneously
improved. The MC-CDMA combined with the MIMO technique, has become a core technology for future mobile radio
communication system. However, possible potential gain in spectral efficiency is challenged by the receiver’s ability to
accurately detect the symbol due to inter symbol interference (ISI). Multipath propagation, mobility of transmitter,
receiver and local scattering cause the signal to be spread in frequency, different arrival time and angle, which results in
ISI in the received signal. This will affect overall system performance. The use of MC-CDMA mitigates the problem of
time dispersion. However, still it is necessary to remove the amplitude and phase shift caused by channel. To solve this
problem, a multiple antenna array can be used at the receiver, not only for spectral efficiency or gain enhancement, but
also for interference suppression. This can be done by the, efficient channel estimation with strong equalization. This
paper proposes MIMO MC-CDMA system, Minimum mean square error (MMSE) equalization with pilot based
channel estimation. The simulation result shows improved Bit error rate (BER) performance when the sub carrier (SC)
and antenna configuration were increased
Estimation of bit error rate in 2×2 and 4×4 multi-input multioutput-orthogon...IJECEIAES
Multiple-input, multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems with multiple input antennas and multiple output antennas in dynamic environments face the challenge of channel estimation. To overcome this challenge and to improve the performance and signal-tonoise ratio, in this paper we used the Kalman filter for the correct estimation of the signal in dynamic environments. To obtain the original signal at the receiver end bit error rate factor plays a major role. If the signal to noise ratio is high and the bit error rate is low then signal strength is high, the signal received at the receiver end is almost similar to the i th transmitted signal. The dynamic tracking characteristic of Kalman filter is used to establish a dynamic space-time codeword and a collection of orthogonal pilot sequences to prevent interference among transmissions in this paper. Using the simulation, the Kalman filter method can be compared to the other channel estimation method presented in this paper that can track timevarying channels rapidly.
Performance evaluation of high mobility OFDM channel estimation techniques IJECEIAES
In wireless communication, Orthogonal Frequency Division Multiplexing (OFDM) has been adopted due to its robustness to multipath fading and high data rate transmissions. At the other hand, the performance of OFDM systems severely degraded due to multi-path fading and Doppler frequency shifts in mobile systems, which causes inter-carrier-interference (ICI). Thus, Estimation of channel parameters is required at the receiver using a pre designed estimator where pilot tones are inserted in each OFDM symbol. In this paper, a random pilot data are generated and inserted in each OFDM symbol at equally spaced locations. The performance test of Least Square (LS) and Linear Minimum Mean Square (LMMSE) estimation methods are proposed with Discrete Fourier Transform (DFT) based on both LS and LMMSE, where different ITU channel models are considered in order to compare their performance for data transmission in high mobile systems with different Doppler frequencies exceeds 200 Hz and minimal number of pilots.
Integrated approach for efficient power consumption and resource allocation i...IJECEIAES
The growing interest towards wireless communication advancement with smart devices has provided the desired throughput of wireless communication mechanisms. But, attaining high-speed data packets amenities is the biggest issue in different multimedia applications. Recently, OFDM has come up with the useful features for wireless communication however it faces interference issues at carrier level (intercarrier interferences). To resolve these interference issues in OFDM, various existing mechanisms were utilized cyclic prefix, but it leads to redundancy in transmitted data. Also, the transmission of this redundant data can take some more power and bandwidth. All these limitations factors can be removed from a parallel cancellation mechanism. The integration of parallel cancellation and Convolution Viterbi encoding and decoding in MIMOOFDMA will be an effective solution to have high data rate which also associations with the benefits of both the architectures of MIMO and OFDMA modulation approaches. This paper deals with this integrated mechanism for efficient resource allocation and power consumption. For performance analysis, MIMO-OFDMA system is analyzed with three different approaches likeMIMO-OFDM system without parallel cancellation (MIMO-OFDMA-WPC), MIMO-OFDMA System with parallel cancellation (MIMO-OFDMA-PC) and proposed IMO-OFDMA system with parallel cancellation and Convolution Viterbi encoding/decoding (pMIMO-OFDMAPC &CVed) for 4x4 transmitter and receiver. Through performance analysis, it is found that the proposed system achieved better resource allocation (bandwidth) with high data rate by minimized BER rate and achieved least power consumption with least BER.
Improved Algorithm for Throughput Maximization in MC-CDMAVLSICS Design
The Multi-Carrier Code Division Multiple Access (MC-CDMA) is becoming a very significant downlink multiple access technique for high-rate data transmission in the fourth generation wireless communication systems. By means of efficient resource allocation higher data rate i.e. throughput can be achieved. This paper evaluates the performance of group (subchannel) allocation criteria employed in downlink transmission, which results in throughput maximization. Proposed algorithm gives the modified technique of sub channel allocation in the downlink transmission of MC-CDMA systems. Simulation are carried out for all the three combining schemes, results shows that for the given power and BER proposed algorithm comparatively gives far better results .
Analysis of System Capacity and Spectral Efficiency of Fixed-Grid NetworkIJCNCJournal
In this article, the performance of a fixed grid network is examined for various modulation formats to estimate the system's capacity and spectral efficiency. The optical In-phase Quadrature Modulator (IQM) structure is used to build a fixed grid network modulation, and the homodyne detection approach is used for the receiver. Data multiplexing is accomplished using the Polarization Division Multiplexed (PDM) technology. 100 Gbps, 150 Gbps, and 200 Gbps data rates are transmitted under these circumstances utilizing various modulation formats. Various pre-processing and signal recovery steps are explained by using modern digital signal processing systems. The achieved spectrum efficiencies for PM-QPSK, PM-8 QAM, and PM-16 QAM, respectively, were 2, 3, and 4 (bits/s)/Hz. Different modulation like PM-QPSK, PM-8-QAM, and PM-16-QAM each has system capacities of 8-9, 12-13.5, and 16-18 Tbps and it reaches transmission distances of 3000, 1300, and 700 kilometers with acceptable Bit Error Rate (BER≤ 2× 10-3) respectively. Peak optical power for received signal detection and full width at half maximum is noted for the different modulations under a fixed grind network.
Performance Analysis for Parallel MRA in Heterogeneous Wireless NetworksEditor IJCATR
This paper analysis a different methods to find optimal path for services and power allocation to heterogeneous wireless network. Under heterogeneous wireless networks, a user can send data through a single or multi RATs (Radio Access Technology) simultaneously. The objective of this paper is to choose the optimal path for the services and power allocation to that bandwidth (BW) distributed joint allocation algorithm using Newton and modified Newton are adopted and the total system capacity compared. The analysis is done in Matlab and simulation results are compared. The numerical result shows that compare to Newton method, modified Newton method maximize the total system capacity.
Performance analysis of multilayer multicast MANET CRN based on steiner minim...TELKOMNIKA JOURNAL
In this study, the multicast mobile ad hoc (MANET) CRN has been developed, which involves multi-hop and multilayer consideration and Steiner minimal tree (SMT) algorithm is employed as the router protocol. To enhance the network performance with regards to throughput and packet delivery rate (PDR), as channel assignment scheme, the probability of success (POS) is employed that accounts for the channel availability and the time needed for transmission when selecting the best channel from the numerous available channels for data transmission from the source to all destinations nodes effectively. Within Rayleigh fading channels under various network parameters, a comparison is done for the performance of SMT multicast (MANET) CRN with POS scheme versus maximum data rate (MDR), maximum average spectrum availability (MASA) and random channel assignment schemes. Based on the simulation results, the SMT multicast (MANET) CRN with POS scheme was seen to demonstrate the best performance versus other schemes. Also, the results proved that the throughput and PDR performance are improved as the number the primary channels and the channel’s bandwidth increased while dropped as the value of packet size D increased. The network’s performance grew with rise in the value of idle probability (푃퐼) since the primary user’s (PU) traffic load is low when the value of 푃퐼 is high.
Analysis of System Capacity and Spectral Efficiency of Fixed-Grid NetworkIJCNCJournal
In this article, the performance of a fixed grid network is examined for various modulation formats to estimate the system's capacity and spectral efficiency. The optical In-phase Quadrature Modulator (IQM) structure is used to build a fixed grid network modulation, and the homodyne detection approach is used for the receiver. Data multiplexing is accomplished using the Polarization Division Multiplexed (PDM) technology. 100 Gbps, 150 Gbps, and 200 Gbps data rates are transmitted under these circumstances utilizing various modulation formats. Various pre-processing and signal recovery steps are explained by using modern digital signal processing systems. The achieved spectrum efficiencies for PM-QPSK, PM-8 QAM, and PM-16 QAM, respectively, were 2, 3, and 4 (bits/s)/Hz. Different modulation like PM-QPSK, PM-8-QAM, and PM-16-QAM each has system capacities of 8-9, 12-13.5, and 16-18 Tbps and it reaches transmission distances of 3000, 1300, and 700 kilometers with acceptable Bit Error Rate (BER≤ 2× 10-3) respectively. Peak optical power for received signal detection and full width at half maximum is noted for the different modulations under a fixed grind network.
Random Relay Selection Based Heuristic Optimization Model for the Scheduling ...IJCNCJournal
Cognitive Radio Network (CRN) provides effective capabilities for resource allocation with the valuable spectrum resources in the network. It provides the effective allocation of resources to the unlicensed users or Secondary Users (SUs) to access the spectrum those are unused by the licensed users or Primary Users (Pus). This paper develops an Optimal Relay Selection scheme with the spectrum-sharing scheme in CRN. The proposed Cross-Layer Spider Swarm Shiftingis implemented in CRN for the optimal relay selection with Spider Swarm Optimization (SSO). The shortest path is estimated with the data shifting model for the data transmission path in the CRN. This study examines a cognitive relay network (CRN) with interference restrictions imposed by a mobile end user (MU). Half-duplex communication is used in the proposed system model between a single primary user (PU) and a single secondary user (SU). Between the SU source and SU destination, an amplify and forward (AF) relaying mechanism is also used. While other nodes (SU Source, SU relays, and PU) are supposed to be immobile in this scenario, the mobile end user (SU destination) is assumed to travel at high vehicle speeds. The suggested method achieves variety by placing a selection combiner at the SU destination and dynamically selecting the optimal relay for transmission based on the greatest signal-to-noise (SNR) ratio. The performance of the proposed Cross-Layer Spider Swarm Shifting model is compared with the Spectrum Sharing Optimization with QoS Guarantee (SSO-QG). The comparative analysis expressed that the proposed Cross-Layer Spider Swarm Shifting model delay is reduced by 15% compared with SSO-QG. Additionally, the proposed Cross-Layer Spider Swarm Shiftingexhibits the improved network performance of ~25% higher throughput compared with SSO-QG.
Random Relay Selection based Heuristic Optimization Model for the Scheduling ...IJCNCJournal
Cognitive Radio Network (CRN) provides effective capabilities for resource allocation with the valuable spectrum resources in the network. It provides the effective allocation of resources to the unlicensed users or Secondary Users (SUs) to access the spectrum those are unused by the licensed users or Primary Users (Pus). This paper develops an Optimal Relay Selection scheme with the spectrum-sharing scheme in CRN. The proposed Cross-Layer Spider Swarm Shiftingis implemented in CRN for the optimal relay selection with Spider Swarm Optimization (SSO). The shortest path is estimated with the data shifting model for the data transmission path in the CRN. This study examines a cognitive relay network (CRN) with interference restrictions imposed by a mobile end user (MU). Half-duplex communication is used in the proposed system model between a single primary user (PU) and a single secondary user (SU). Between the SU source and SU destination, an amplify and forward (AF) relaying mechanism is also used. While other nodes (SU Source, SU relays, and PU) are supposed to be immobile in this scenario, the mobile end user (SU destination) is assumed to travel at high vehicle speeds. The suggested method achieves variety by placing a selection combiner at the SU destination and dynamically selecting the optimal relay for transmission based on the greatest signal-to-noise (SNR) ratio. The performance of the proposed Cross-Layer Spider Swarm Shifting model is compared with the Spectrum Sharing Optimization with QoS Guarantee (SSO-QG). The comparative analysis expressed that the proposed Cross-Layer Spider Swarm Shifting model delay is reduced by 15% compared with SSO-QG. Additionally, the proposed Cross-Layer Spider Swarm Shiftingexhibits the improved network performance of ~25% higher throughput compared with SSO-QG.
Impulse Radio Ultra WideBand (IR-UWB) commu- nication has proven to be an important
technique for supporting high-rate, short-range, and low-power communication. In this paper, using
detailed models of typical IR-UWB transmitter and receiver structures, we model the energy
consumption per information bit in a single linkof an IR-UWB system, considering packet overhead,
retransmissions, and a Nakagami-m fading channel. Using this model, we minimize the energy
consumption per information bit by finding the optimum packet length and the optimum number of
RAKE fingers at the receiver for different transmission distances, using Differential Phase-shift keying
(DBPSK), Differential Pulse-position Modulation (DPPM) and On-off Keying (OOK), with coherent
and non-coherent detection. The increasing demand for wireless communication introduces efficient
spectrum utilization challenge. To address this challenge, cognitive radio (CR) is emerged as the key
technology; which enables opportunistic access to the spectrum. CR is a form of wireless
communication in which a transceiver can intelligently detect which communication channels are in
use and which are not, and instantly move into vacant channels while avoiding occupied ones..
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...
I010614347
1. IOSR Journal of Electronics and Communication Engineering (IOSR-JECE)
e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 10, Issue 6, Ver. I (Nov - Dec .2015), PP 43-47
www.iosrjournals.org
DOI: 10.9790/2834-10614347 www.iosrjournals.org 43 | Page
Performance analysis for Adaptive Subcarriers Allocation in
Coherent Optical OFDM System
Harsimran Jit Kaur1
, Maninder Lal Singh2
, Pankaj Kumar3
, B. C Choudhary4
1
School of Electronics and Electrical Engineering, Chitkara University, Jhansla, Rajpura, Patiala- 140401,
Punjab, India.
2
Department of Electronics Technology, Guru Nanak Dev University, Amritsar,-143005, Punjab, India.
3
School of Applied Sciences and Chitkara University Research & Innovation Network, Chitkara University,
Jhansla, Rajpura, Patiala- 140401, Punjab, India.
4
Department of Applied Sciences, NITTTR- 160019, Chandigarh.
Abstract: The constraint to satisfy the need of increased bandwidth requirement for high speed applications
with higher performance has been a motivation to work on Optical Orthogonal Frequency division multiplexing
(OOFDM) technique with coherent detection. We implement the coherent optical OFDM (CO-OOFDM)
technique and investigate the effect of the number of sub-carriers on performance over single mode fiber (SMF)
links. To explore improvement in performance adaptive subcarriers has been selected by assigning subcarriers
to user according to the conditions of channel. An adaptive subcarrier allocation has been investigated and
performance comparison for proportional and equal allocation has been carried over.
Keywords: OOFDM, BER, SNR, Subcarriers.
I. Introduction
Orthogonal Frequency division multiplexing (OFDM) has been the most attractive multiple access
technique to meet the demand of high data rate applications due to its robustness and flexibility in resource
allocation. OFDM divides wideband channel into multiple parallel narrowband sub-channels by using fixed
number of orthogonal sub-carriers which has been splitting high data rate signal into parallel low data rate
signals. As OFDM modulation scheme has been using partially overlapped subcarriers, it provides high spectral
efficiency [1]. Orthogonal Frequency division multiple access (OFDMA) has motivated the researchers due to
less complexity [2, 3]. It has been proposed that Coherent Optical OFDM (CO-OFDM) is a promising technique
for next generation optical networks to achieve high spectral efficiency while maximising SNR, as it holds the
advantages of both a coherent technique and an OFDM technology [4,5]. Coherent detection provides is
linearity in recovering the input signal to reduce noise [6]. Coherent transmissions for increasing the system
capacity by sub-carriers modulation with dual polarized Quadrature phase shift keying (DP-QPSK) in multi-
input multi-output (MIMO) configurations has been studied [7]. Equalizers play vital role to combat dispersion
effects leading to Inter symbol Interference (ISI) during transmission [8]. But complexity of system increases as
we add equalizers in system. OFDM has been an effective technique to lessen the ISI [9]. Requirement of
equalizers can be reduced using careful design in OOFDM system. Although due to inherited features like
resilience to noise CO-OFDM transmission had gained increased interest of optical research community but
performance system is degraded due to certain linear and non linear impairments [10]. For increasing system
performance various methods has been proposed including Digital signal Processing (DSP) based Electronic
Dispersion Compensation(EDC), Optimization of network parameters [11]. Adaptation of network parameters
based on channel conditions can considerably improve transmission performance. Implementation of adaptive
technique for adapting network parameters demands transmitter to estimate the response of channel whose
knowledge could be achieved from past channel quality estimations [12]. Static resource allocation schemes
results in poor spectral efficiency, whereas in dynamic resource allocation distribution of resources could be
carried over according to the channel state and the demand of user leading to improved spectral efficiency.
Subcarriers are among most important resources of a network whose allocation is very important issue for
spectral efficiency. The effect of adaptive cyclic prefix (ACP), the number of subcarriers, has been investigated
for IM-DD (intensity modulated direct detection) OOFDM [13-17] but these effects are not been much
explored on CO-OFDM for single mode fiber (SMF) for performance improvement. In section II adaptive
subcarriers allocation schemes has been investigated to study performance improvement of CO-OFDM system
in multiuser environment.
2. Performance analysis for Adaptive Subcarriers Allocation in Coherent Optical OFDM System
DOI: 10.9790/2834-10614347 www.iosrjournals.org 44 | Page
II. System Model
Fig. 1. represents simulation model using CO-OFDM transmission. Transmitter is passing complex
valued data stream through serial to parallel converter producing Nx1 vector which is further mapped using
modulation scheme Quadrature Amplitude Modulation with varying modulation index M to 16, 64,256.
Fig. 1: System Model for CO-OFDM system
Matlab has been used for OFDM coding and decoding, Optsim has been used for modelling the optical
OFDM transmission system. Matlab generated OFDM modulated data has been given to Optsim for optical
transmission. Binary data generated by random generator has been mapped to M-QAM symbol. Simulation has
been carried over an optical communication system with data rates 10 Gb/s at 1550 nm over single-mode (SM)
fiber of length 1000(10x100 km) with fiber average beat length 5m [20]. On the assumption that transmitter has
perfect knowledge about channel resource allocation has been executed at the transmitter side.
III. Principle Of Adaptive Subcarrier Allocation Technique
For maximising system capacity, achieving desired transmission performance and increasing
performance robustness the usage of adaptation techniques in multicarrier OFDM system has been a solution.
Among various adaptive loading algorithms adaptive subcarrier allocation technique helps in performance
improvement in which subcarriers may be assigned to user according to channel conditions. Depending upon the
frequency response of fiber link the subcarriers of CO-OFDM signals faces distortion leading to degraded
performance. To tackle this hurdle for achieving spectrally efficient high performance CO-OFDM system, this
paper presents an adaptive subcarrier allocation method. Allocation of subcarriers has been carried over
following two different strategies proportional allocation and equal allocation. Applicability of each scheme
depends on the requirement of network like network may demand fair distribution of data rate among all users
or it may demand high throughput. Although the subcarrier assignment along with power distribution has been
great interest for researchers for OFDMA wireless networks but it has not been much explored for optical
networks.
1. Proportional Allocation
For proportional allocation a method has been presented for allocating subcarriers in CO-OFDM
system on the basis of channel conditions monitored by Signal to Noise ratio (SNR) with condition to attain fair
allocation amongst users and maximize data rate. The target of achieving fairness and data rate maximization is
obtained by devising solution in which fairness among users has been obtained by adding set of non linear
constraints. To achieve this, maximized data rate is used as objective function and set of non linear constraints
are added for getting fairness. In the proposed solution for proportional allocation, the subcarrier allocation has
been determined by permitting each user to select subcarrier with priority for those having highest Signal to
noise ratio (SNR) and minimum proportional data rate. Algorithms proceeds for maximization of data rate.
It has been proposed that data rate for M- level QAM can be approximated in terms of BER as eq.1 .
corresponds to data rate of kth
user represented as :
(1)
Where constant Ѓ is calculated in terms of Bit error rate for M-QAM as – [18]. Mathematically,
the problem for proportional subcarrier allocation could be represented as eq.2:
3. Performance analysis for Adaptive Subcarriers Allocation in Coherent Optical OFDM System
DOI: 10.9790/2834-10614347 www.iosrjournals.org 45 | Page
Subject to
Condition 2
(2)
Where K represents total number of users, N is total number of subcarriers, is Signal to noise
ratio for kth
user nth
subcarrier, According to condition 1 can have value either 0 or 1 depending if n
subcarrier is used by user k or not. Condition 2 illustrate that each subcarrier can be used by only one user. In
the last as per condition 3 is predetermined values for ensuring fairness in subcarrier allocation.
The desired target of maximizing data rate and proportional allocation among users with assumption of equal
power distribution has been attained in presented method in two steps. First involves determination of minimum
number of subcarriers to be allocated to each user and second includes assignment of subcarriers to each user so
as to maximize data rate while achieving fairness in allocation. After determining the minimum number of
subcarriers to be assigned to each user, algorithm proceeds by initializing all variables, then in next step
followed by determination of highest value of SNRk.n. Next step proceeds to achieve fairness in subcarrier
allocation where assignment is base on greedy approach i.e user having least data rate divided by proportionality
constant has been selected as most needy user for subcarrier assignment. During this step each user can gets the
allocation of Nk subcarriers. In next step the allocation of remaining subcarriers has been carried over. This step
takes care that each user can achieve at the maximum of one unassigned subcarrier so as to avoid that user with
maximum SNR should not get all the unallocated subcarriers. This strategy achieves proportional fairness
among subcarriers while maximising data capacity.
2. Equal allocation
If in eq. 2 condition 3 the value of rate constants is made unity it become the condition where all
users have all users have the same capacity and the data rate has been maximized. In order to make comparison
a special case of maximum fairness has been considered where the value of proportional constants has been
made equal and unity i.e
Performance comparison has been carried in this paper for proportional fairness and maximum fairness for
subcarrier allocation in the form of Bit error rate (BER) and SNR to emphasize the better conduct of proposed
scheme.
IV. Simulation Results
In this section the simulation results for performance of adaptive subcarrier allocation has been
presented over CO-OFDM. In particular the performance comparison between proportional subcarrier allocation
and equal allocation has been presented.
The modulation schemes considered during analysis includes 16 QAM, 64 QAM and 256 QAM.
Figure 2(a), 2(b), 2(c) presents the performance comparison of proposed proportional allocation and equal
subcarrier allocation for 16 QAM, 64QAM and 256 QAM by considering maximum number of subcarriers as 16
where bit error rate has been evaluated for different values of SNR. The proportional allocation allocates
subcarriers by monitoring channel conditions to maximize capacity along with achievement of fairness in
subcarrier allocation by allocating number of subcarriers which is proportional to data rate, whereas in equal
subcarrier allocation all users are allocated same number of subcarriers. This equal subcarrier allocation results
in inefficient utilization of resources as users with poor channel conditions and low data rate requirement may
achieve more than required number of subcarriers leading to poor system performance. On comparing these
results it could be clear inferred that adaptive subcarrier allocation instead of fixed equal subcarrier allocation
can improve the system performance. Improvement of 9-11 db in terms of SNR for achieving same BER has
been observed between adaptive subcarrier allocation and equal allocation. For evaluating the simulated results
reference optimum has been selected using analytical expression of Eq. (3) [19] for theoretical BER.
BER= (3)
In Eq. (3) M represents modulation order, Q quality factor; SNR as Signal to Noise Ratio. Simulated
results are achieving quite optimum results when compared with theoretical expectations using adaptive
subcarrier allocation strategy. Achievement of BER 10-9
has been obtained by 16 QAM system with SNR
value 24.5 dB, 64 QAM system with SNR value 29 dB , 256 QAM system with SNR value 30 dB using
maximum number of subcarriers 16.
4. Performance analysis for Adaptive Subcarriers Allocation in Coherent Optical OFDM System
DOI: 10.9790/2834-10614347 www.iosrjournals.org 46 | Page
Fig. 2(a): BER comparison for two subcarrier allocation using 16 QAM with 16 subcarriers.
Fig. 2(b): BER comparison for two subcarrier allocation using 64 QAM with 16 subcarriers
Fig.2(c): BER comparison for two subcarrier allocation using 256 QAM with 16 subcarriers.
V. Conclusion
For CO-OFDM system in comparison to usage of long CP for combating with dispersion effects
increasing the number of subcarriers has been more effective. For static subcarrier allocation optimum number
of subcarriers over SMF link of 1000 km with 16 QAM CO-OFDM transmission has been identified to be 64.
Further, this paper presents usage of resources like subcarriers in adaptive manner. In particular comparison of
proportional subcarrier allocation with equal subcarrier allocation has been carried over. An improvement of
improvement of 9-11 dB in terms of SNR for achieving same BER has been observed between adaptive
subcarrier allocation and equal allocation. The proposed subcarrier allocation is based on estimation of channel
conditions along with fair allocation strategy to maximize channel capacity, whereas the equal subcarriers
allocation is based on equal number of subcarrier assignment. The proposed proportional subcarrier assignment
provides better performance in terms of BER and throughput.
5. Performance analysis for Adaptive Subcarriers Allocation in Coherent Optical OFDM System
DOI: 10.9790/2834-10614347 www.iosrjournals.org 47 | Page
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