Cellular CDMA systems are usually affected by interference experienced by users in adjacent
cells that decrease the Quality of Services in wireless communication network. Hence, interference is the
limiting factor of capacity in CDMA cellular and it is one of the problems fighting against the high efficiency
of any mobile network. In this paper, a mathematical model to estimate the average number of users
contributing in inter-cell interference at the busy hours of CDMA network is proposed. As the power
exponent value has significant affect on interferer signal attenuation and hence other-cells interference,
measurements were carried through a drive test to determine the received power level at various distance
from CDMA base stations at Baghdad. The results obtained show that the power exponent was 2.71. This
value was applied in dual-slop path loss model to determine the expected interference factor, and the
number of users that can be hold at each cell. Simulations showed that users at a boundary cell generate
more interference than those close to the base station. Furthermore, it was denoted that greater number of
users caused to increase the interference factor, and greater power exponent value result in interference
factor reduction.
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.
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.
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.
RESOURCE ALLOCATION TECHNIQUE USING LOAD MATRIX METHOD IN WIRELESS CELLULAR S...cscpconf
An efficient resource allocation is one of the greatest challenges in wireless cellular
communication. The resource allocation schemes avoid wastage of resources by allocating
resources to a mobile terminal over a short period of time, providing quality of service over
wireless networks is the most stressing point for service providers. In general a high degree of
sharing is efficient, but requires service protection mechanisms to guarantee the QoS for all
services. In this paper we address the multi cell interference on overall radio resource
utilization and propose a new strategy for resource allocation in multi cell systems. we also
propose a joint management of interference within and between cells for allocation of radio
resources , Simulation results are showing that there is a significant improvement in the resource utilization so that overall network performance.
Estimation and design of mc ds-cdma for hybrid concatenated coding in high sp...eSAT Journals
Abstract The design of Multi Carrier Direct Sequence Code Division Multiple Access (MC-DS-CDMA) structure which generalizes serial and parallel concatenated code is investigated to this project. This model is ideal for designing various codes in the performance of both error floor and water floor region. We propose a concatenated code for transmitter block which is used for multi carrier direct sequence CDMA technique. Simulation results of MC-DS-CDMA uplink system using Cadence software shows the various parameters such as memory, Execution time and number of transient steps required for the Execution of MC-DS-CDMA uplink system was estimated and also power consumed was determined for each block in the transmitter. An improved concatenated code model is used for uplink mobile communication. Further system performance improvements can be obtained by concatenating inner code and outer code and the results of computer simulations demonstrate that the performance of the concatenated code was investigated. Keywords: Code Division Multiple Access, Concatenated code, inner code, outer code, interleaving and power analysis.
Full-duplex user-centric communication using non-orthogonal multiple accessTELKOMNIKA JOURNAL
This paper proposes an improved user-centric Non-Orthogonal Multiple Access (NOMA) communication in two-base station networks with in-band full duplex (IBFD) user. We derive the achievable rates of the proposed user-centric NOMA systems. For benchmarking purposes, we also derive the achievable rate for the user-centric system deploying conventional NOMA schemes, Orthogonal Multiple Access (OMA) schemes and point-point communication systems. We then analyze and simulate the performance of the proposed and all the benchmarked systems. We found that our proposed user-centric NOMA approach has a 64% improvement in the total achievable rate when compared to the benchmarked approach under similar power constraint.
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.
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.
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.
RESOURCE ALLOCATION TECHNIQUE USING LOAD MATRIX METHOD IN WIRELESS CELLULAR S...cscpconf
An efficient resource allocation is one of the greatest challenges in wireless cellular
communication. The resource allocation schemes avoid wastage of resources by allocating
resources to a mobile terminal over a short period of time, providing quality of service over
wireless networks is the most stressing point for service providers. In general a high degree of
sharing is efficient, but requires service protection mechanisms to guarantee the QoS for all
services. In this paper we address the multi cell interference on overall radio resource
utilization and propose a new strategy for resource allocation in multi cell systems. we also
propose a joint management of interference within and between cells for allocation of radio
resources , Simulation results are showing that there is a significant improvement in the resource utilization so that overall network performance.
Estimation and design of mc ds-cdma for hybrid concatenated coding in high sp...eSAT Journals
Abstract The design of Multi Carrier Direct Sequence Code Division Multiple Access (MC-DS-CDMA) structure which generalizes serial and parallel concatenated code is investigated to this project. This model is ideal for designing various codes in the performance of both error floor and water floor region. We propose a concatenated code for transmitter block which is used for multi carrier direct sequence CDMA technique. Simulation results of MC-DS-CDMA uplink system using Cadence software shows the various parameters such as memory, Execution time and number of transient steps required for the Execution of MC-DS-CDMA uplink system was estimated and also power consumed was determined for each block in the transmitter. An improved concatenated code model is used for uplink mobile communication. Further system performance improvements can be obtained by concatenating inner code and outer code and the results of computer simulations demonstrate that the performance of the concatenated code was investigated. Keywords: Code Division Multiple Access, Concatenated code, inner code, outer code, interleaving and power analysis.
Full-duplex user-centric communication using non-orthogonal multiple accessTELKOMNIKA JOURNAL
This paper proposes an improved user-centric Non-Orthogonal Multiple Access (NOMA) communication in two-base station networks with in-band full duplex (IBFD) user. We derive the achievable rates of the proposed user-centric NOMA systems. For benchmarking purposes, we also derive the achievable rate for the user-centric system deploying conventional NOMA schemes, Orthogonal Multiple Access (OMA) schemes and point-point communication systems. We then analyze and simulate the performance of the proposed and all the benchmarked systems. We found that our proposed user-centric NOMA approach has a 64% improvement in the total achievable rate when compared to the benchmarked approach under similar power constraint.
A Novel Handoff Necessity Estimation Approach Based on Travelling DistanceIJAAS Team
Mobility management is one of the most important challenges in Next
Generation Wireless Networks (NGWNs) as it enables users to move across
geographic boundaries of wireless networks. Nowadays, mobile
communications have heterogeneous wireless networks offering variable
coverage and Quality of Service (QoS). The availability of alternatives
generates a problem of occurrence of unnecessary handoff that results in
wastage of network resources. To avoid this, an efficient algorithm needs to
be developed to minimize the unnecessary handoffs. Conventionally,
whenever Wireless Local Area Network (WLAN) connectivity is available,
the mobile node switch from cellular network to wireless local area network
to gain maximum use of high bandwidth and low cost of wireless local area
network as much as possible. But to maintain call quality and minimum
number of call failure, a considerable proportion of these handovers should
be determined. Our algorithm makes the handoff to wireless local area
network only when the Predicted Received Signal Strength (PRSS) falls
below a threshold value and travelling distance inside the wireless local area
network is larger than a threshold distance.Through MATLAB simulation,
we show that our algorithm is able to improve handover performance.
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 .
Performance Analysis of Energy Optimized LTE-V2X Networks for Delay Sensitive...IJCNCJournal
Energy-efficient relaying technology in multi-hop data transmission can help the challenges faced in cellular Vehicle-to-Everything (cellular-V2X) communication. However, due to high demand of emergency service requirements of the systems such as Public Protection and Disaster Relief (PPDR), National Security and Public Safety (NSPS), Intelligent Transport System (ITS) etc., least energy consumed user equipment (UEs)/Vehicular-UEs are required which can either run real-time applications or relay the application data. To support these scenarios, we present a high way based system model in rural area and enhance its scope for applying single-hop direct, relay assisted multi-hop cellular-V2X and Store-CarryForward (SCF) modes of uplink data transmission. We compare the performance of three modes of transmissions in terms of overall energy consumption and overall transmission delay with specific delay constraints of VoIP and video applications. With the varying cell radius and irrespective type of applications, our numerical results, validated with ns-3 show that, least energy is always consumed in SCF mode due to its inherent property but applications suffer a lot due to high delay incurred whereas singlehop direct mode shows the reverse. When compared with cellular-V2X mode, overall transmission delay for single-hop direct mode is acceptable within cell radius 600m but beyond that, relay assisted multi-hop cellular-V2X mode always outperforms (with low latency and moderate energy consumption).
GPSFR: GPS-Free Routing Protocol for Vehicular Networks with Directional Ante...ijwmn
Efficient and practical communications between large numbers of vehicles are critical in providing high level of safety and convenience to drivers. Crucial real-time information on road hazard, traffic conditions and driver services must be communicated to vehicles rapidly even in adverse environments, such as “urban canyons” and tunnels. We propose a novel routing protocol in vehicular networks that does not require position information (e.g. from GPS) but instead rely on relative position that can be determined dynamically. This GPS-Free Geographic Routing (GPSFR) protocol uses the estimated relative position of vehicles and greedily chooses the best next hop neighbor based on a Balance Advance (BADV) metric which balances between proximity and link stability in order to improve routing performance. In this paper, we focuses primarily on the complexity of routing in highways and solves routing problems that arise when vehicles are near interchanges, curves, and merge or exit lanes of highways. Our simulation results show that by taking relative velocity into account, GPSFR reduces link breakage to only 27% that of GPSR in the dense network. Consequently, GPSFR outperforms GPSR in terms of higher data delivery ratio, lower delay, less sensitivity of the network density and route paths’length
MULTI-CRITERIA HANDOVER DECISION FOR HETEROGENEOUS NETWORKS: CARRIER AGGREGAT...IJCNCJournal
Carrier aggregation and integration of heterogeneous networks allow the mobile user equipment to benefit from wider bandwidth and radio coverage of different access technologies. However, these technologies have increased handoff scenario probability through user equipment’s mobility, leading to high outage probability and low throughput. Handover is an important aspect of mobility management which allows users to migrate from one cell to another without losing connections. But no lone access technology meets the requirements of providing seamless communication without loss and delay. Therefore, high-quality service continuity and reliable user equipment access to network anywhere and at any time require the
design of an appropriate handover decision algorithm. In this paper, a multi-criteria based handover decision-making algorithm is proposed to evade loss of communication and provide better performance to the system. It adaptively makes handover decisions based on different decision criteria (load, availability of resources, and the handover scenario type) in addition to signal interference to noise ratio. The multicriteria handover decision making algorithm-based method chooses among the cells that satisfy the requirements for the handover. As compared to some existing handover decision algorithms, simulation result shows that this algorithm improves system performance in terms of handover failure by 93%, 72%,
and 58%; radio link failure reduction by 77%, 43%, and 22%; and handover ping–pong by 81%, 59%, and 36% over the conventional received signal strength, received wireless transmission line, and multiinfluence factor hand over decisions respectively.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
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.
Propagation Path Loss Modeling and Outdoor Coverage Measurements Review in Mi...IJECEIAES
The global bandwidth inadequacy facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks, and mmWave band is one of the promising candidates due to wide spectrum. This paper presents propagation path loss and outdoor coverage and link budget measurements for frequencies above 6 GHz (mm-wave bands) using directional horn antennas at the transmitter and omnidirectional antennas at the receiver. This work presents measurements showing the propagation time delay spread and path loss as a function of separation distance for different frequencies and antenna pointing angles for many types of real-world environments. The data presented here show that at 28 GHz, 38 GHz and 60 GHz, unobstructed Line of Site (LOS) channels obey free space propagation path loss while non-LOS (NLOS) channels have large multipath delay spreads and can utilize many different pointing angles to provide propagation links. At 60 GHz, there is more path loss and smaller delay spreads. Power delay profiles PDPs were measured at every individual pointing angle for each TX and RX location, and integrating each of the PDPs to obtain received power as a function of pointing angle. The result shows that the mean RMS delay spread varies between 7.2 ns and 74.4 ns for 60 GHz and 28 GHz respectively in NLOS scenario.
DESIGN OF A COMPACT CIRCULAR MICROSTRIP PATCH ANTENNA FOR WLAN APPLICATIONS pijans
This paper presents the design of a compact circular microstrip patch antenna for WLAN applications which covers the band 5.15 to 5.825 GHz. The antenna is designed using 1.4mm thick FR-4 (lossy)substrate with relative permittivity 4.4 and a microstrip line feed is used. The radius of the circular patch is chosen as 7.62mm. To reduce the size and enhance the performance of the proposed antenna, a circular slot is loaded on circular patch and a square slot is etched on the ground plane of dimension 30mm×30mm. Design of the antenna is carried out using CST Microsoft Studio Sonimulation Software. The proposed antenna resonates at 5.5 GHz with a wider bandwidth of 702 MHz and it provides low return loss of -31.58 dB, good gain of 3.23 dB and directivity of 4.28 dBi and high efficiency of around 79% against the resonance frequency. The geometry of the proposed circular antenna with reduced size and its various performance parameters such as return loss, bandwidth, VSWR, gain, directivity, efficiency and radiation pattern plots are presented and discussed.
Energy-efficient user association mechanism enabling fully hybrid spectrum sh...TELKOMNIKA JOURNAL
Spectrum sharing (SS) is a promising solution to enhance spectrum utilization in future cellular
systems. Reducing the energy consumption in cellular networks has recently earned tremendous attention
from diverse stakeholders (i.e., vendors, mobile network operators (MNOs), and government) to decrease
the CO2 emissions and thus introducing an environment-friendly wireless communication. Therefore,
in this paper, joint energy-efficient user association (UA) mechanism and fully hybrid spectrum sharing
(EE-FHSS) approach is proposed considering the quality of experience QoE (i.e., data rate) as the main
constraint. In this approach, the spectrum available in the high and low frequencies (28 and 73 GHz) is
sliced into three portions (licensed, semi-shared, and fully-shared) aims to serve the users (UEs)
that belong to four operators in an integrated and hybrid manner. The performance of the proposed
QoE-Based EE UA-FHSS is compared with the well-known maximum signal-to-interference-plus-noise
ratio (max-SINR UA-FHSS). Numerical results show that remarkable enhancement in terms of EE for
the four participating operators can be achieved while maintaining a high degree of QoE to the UEs.
A Novel Routing Strategy Towards Achieving Ultra-Low End-to-End Latency in 6G...IJCNCJournal
Compared to 5G, 6G networks will demand even more ambitious reduction in endto-end latency for packet communication. Recent attempts at breaking the barrier of end-to-end millisecond latencies have focused on re-engineering networks using a hybrid approach consisting of an optical-fiber based backbone network architecture coupled with high-speed wireless networks to connect end-devices to the backbone network. In our approach, a wide area network (WAN) is considered with a high-speed optical fiber grid network as its backbone. After messages from a source node enter the backbone network through a local wireless network, these are delivered very fast to an access point in the backbone network closest to the destination node, followed by its transfer to the local wireless network for delivery to the destination node. We propose a novel routing strategy which is based on distributing the messages in the network in such a way that the average queuing delay of the messages through the backbone network is minimized, and also the route discovery time at each router in the backbone network is drastically reduced. Also, multiple messages destined towards a particular destination router in the backbone network are packed together to form a mailbag, allowing further reductions in processing overheads at intermediate routers and pipelining of mailbag formation and route discovery operations in each router. The performance of the proposed approach green based on these ideas has been theoretically analyzed and then simulated using the ns-3 simulator. Our results show that the average end-to-end latency is less than 380 µs (with only 46-79 µs within the backbone network under varying traffic conditions) for a 1 KB packet size, when using a 500 Gbps optical fiber based backbone network laid over a 15 Km × 15 Km area, a 50 Mbps uplink channel from the source to the backbone network, and a 1 Gbps downlink channel from the backbone network to the destination. The significant reduction in end-to-end latency as compared to existing routing solutions clearly demonstrates the potential of our proposed routing strategy for meeting the ultra-low latency requirements of current 5G and future 6G networks, particularly for mobile edge computing (MEC) application scenarios.
Design and software implementation of radio frequency satellite link based on...TELKOMNIKA JOURNAL
The satellite communication providea utilization of radio frequency links. Specific frequencies are dedicated for satellite correspondences through global administrative and coordination procedures which keeps impedance amongframeworks. Over typical work, the satellite receives uplinked indicator fromearth. Progressions its frequency marginally will keep away from self-intervention then re-transmits signal ahead the downlink on the land. Pathloss depicts characteristic Propagate outside the sending signal front as it goes bythe space. A software defined radio (SDR) is a flexible technology that aimsto replace all hardware by software to enables the design of adaptive communications systems such as changing frequencies, modulation schemes and data rates. Applied to small satellites, some of the implications areincreased data through put when down-linking or up-linking by varying communications parameters and making use of one hardware design and implementation for communicating for many missions, just by updating the software. Therefore, development time for small satellite communication systems can be reduced in the future. This paper analyzes, design and software implementation of radio frequency satellite communications links under noisy channels such as phase/frequency offsets and noise temperature. Modulation schemes such as 64QAM system is used based on Matlab tools to implement the results. Obtained results shows a good response that get the goal from the paper.
Magnetic resonance coupling for 5G WPT applicationsjournalBEEI
Inductive Wireless Power Transfer (IWPT) is the most popular and common technology for the resonance coupling power transfer. However, in 2007 it has experimentally demonstrated by a research group from Massachusets Institute of Technology (MIT) that WPT can be improved by using Magnetic Resonance Coupling Wireless Power Transfer (MRC WPT) in terms of the coupling distance and efficiency. Furthermore, by exploiting the unused, high-frequency mm-wave band which are ranging from 3~300 GHz frequency band, the next 5G generations of wireless networks will be able to support a higher number of devices with the increasing data rate, higher energy efficiency and also compatible with the previous technology. In this work, a square planar inductor with the dimension of 6.1 x 6.1 mm is designed, and the resonators have the same self-resonance frequency at 14 GHz. The coil resonators have been laid on Silicon and Oxide substrate to reduce the loss in the design. From the CST software simulation and the analytical model in MATLAB software, it has been shown that the MRC WPT design has improved the performance of IWPT design by 40% power transfer efficiency. MRC WPT design also has larger H-Field value which is 705.5 A/m, as compared to the IWPT design which has only 285.6 A/m when both Transmitter(Tx) and Reciever(RX) is at 0.3 mm coupling distance.
Capacity Improvement of Cellular System Using Fractional Frequency Reuse (FFR)IJEEE
Today wireless communication is mostly used rather than wired communication, due to remote location reach ability, less fault occurrence, less time to commissioning and low cost etc. But wireless network has less frequency spectrum to cover the whole world. To improve the capacity of cellular system in a limited spectrum without major technological changes, frequency is reused in cells. But it offers interferences mostly for cell edge users. To solve the problem of spectral congestion and user capacity, fractional frequency reuse is used. This paper gives idea about different frequency reuse factors, fractional frequency reuse and super cell with sectoring to improve the capacity of cellular system.
A Novel Handoff Necessity Estimation Approach Based on Travelling DistanceIJAAS Team
Mobility management is one of the most important challenges in Next
Generation Wireless Networks (NGWNs) as it enables users to move across
geographic boundaries of wireless networks. Nowadays, mobile
communications have heterogeneous wireless networks offering variable
coverage and Quality of Service (QoS). The availability of alternatives
generates a problem of occurrence of unnecessary handoff that results in
wastage of network resources. To avoid this, an efficient algorithm needs to
be developed to minimize the unnecessary handoffs. Conventionally,
whenever Wireless Local Area Network (WLAN) connectivity is available,
the mobile node switch from cellular network to wireless local area network
to gain maximum use of high bandwidth and low cost of wireless local area
network as much as possible. But to maintain call quality and minimum
number of call failure, a considerable proportion of these handovers should
be determined. Our algorithm makes the handoff to wireless local area
network only when the Predicted Received Signal Strength (PRSS) falls
below a threshold value and travelling distance inside the wireless local area
network is larger than a threshold distance.Through MATLAB simulation,
we show that our algorithm is able to improve handover performance.
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 .
Performance Analysis of Energy Optimized LTE-V2X Networks for Delay Sensitive...IJCNCJournal
Energy-efficient relaying technology in multi-hop data transmission can help the challenges faced in cellular Vehicle-to-Everything (cellular-V2X) communication. However, due to high demand of emergency service requirements of the systems such as Public Protection and Disaster Relief (PPDR), National Security and Public Safety (NSPS), Intelligent Transport System (ITS) etc., least energy consumed user equipment (UEs)/Vehicular-UEs are required which can either run real-time applications or relay the application data. To support these scenarios, we present a high way based system model in rural area and enhance its scope for applying single-hop direct, relay assisted multi-hop cellular-V2X and Store-CarryForward (SCF) modes of uplink data transmission. We compare the performance of three modes of transmissions in terms of overall energy consumption and overall transmission delay with specific delay constraints of VoIP and video applications. With the varying cell radius and irrespective type of applications, our numerical results, validated with ns-3 show that, least energy is always consumed in SCF mode due to its inherent property but applications suffer a lot due to high delay incurred whereas singlehop direct mode shows the reverse. When compared with cellular-V2X mode, overall transmission delay for single-hop direct mode is acceptable within cell radius 600m but beyond that, relay assisted multi-hop cellular-V2X mode always outperforms (with low latency and moderate energy consumption).
GPSFR: GPS-Free Routing Protocol for Vehicular Networks with Directional Ante...ijwmn
Efficient and practical communications between large numbers of vehicles are critical in providing high level of safety and convenience to drivers. Crucial real-time information on road hazard, traffic conditions and driver services must be communicated to vehicles rapidly even in adverse environments, such as “urban canyons” and tunnels. We propose a novel routing protocol in vehicular networks that does not require position information (e.g. from GPS) but instead rely on relative position that can be determined dynamically. This GPS-Free Geographic Routing (GPSFR) protocol uses the estimated relative position of vehicles and greedily chooses the best next hop neighbor based on a Balance Advance (BADV) metric which balances between proximity and link stability in order to improve routing performance. In this paper, we focuses primarily on the complexity of routing in highways and solves routing problems that arise when vehicles are near interchanges, curves, and merge or exit lanes of highways. Our simulation results show that by taking relative velocity into account, GPSFR reduces link breakage to only 27% that of GPSR in the dense network. Consequently, GPSFR outperforms GPSR in terms of higher data delivery ratio, lower delay, less sensitivity of the network density and route paths’length
MULTI-CRITERIA HANDOVER DECISION FOR HETEROGENEOUS NETWORKS: CARRIER AGGREGAT...IJCNCJournal
Carrier aggregation and integration of heterogeneous networks allow the mobile user equipment to benefit from wider bandwidth and radio coverage of different access technologies. However, these technologies have increased handoff scenario probability through user equipment’s mobility, leading to high outage probability and low throughput. Handover is an important aspect of mobility management which allows users to migrate from one cell to another without losing connections. But no lone access technology meets the requirements of providing seamless communication without loss and delay. Therefore, high-quality service continuity and reliable user equipment access to network anywhere and at any time require the
design of an appropriate handover decision algorithm. In this paper, a multi-criteria based handover decision-making algorithm is proposed to evade loss of communication and provide better performance to the system. It adaptively makes handover decisions based on different decision criteria (load, availability of resources, and the handover scenario type) in addition to signal interference to noise ratio. The multicriteria handover decision making algorithm-based method chooses among the cells that satisfy the requirements for the handover. As compared to some existing handover decision algorithms, simulation result shows that this algorithm improves system performance in terms of handover failure by 93%, 72%,
and 58%; radio link failure reduction by 77%, 43%, and 22%; and handover ping–pong by 81%, 59%, and 36% over the conventional received signal strength, received wireless transmission line, and multiinfluence factor hand over decisions respectively.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
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.
Propagation Path Loss Modeling and Outdoor Coverage Measurements Review in Mi...IJECEIAES
The global bandwidth inadequacy facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks, and mmWave band is one of the promising candidates due to wide spectrum. This paper presents propagation path loss and outdoor coverage and link budget measurements for frequencies above 6 GHz (mm-wave bands) using directional horn antennas at the transmitter and omnidirectional antennas at the receiver. This work presents measurements showing the propagation time delay spread and path loss as a function of separation distance for different frequencies and antenna pointing angles for many types of real-world environments. The data presented here show that at 28 GHz, 38 GHz and 60 GHz, unobstructed Line of Site (LOS) channels obey free space propagation path loss while non-LOS (NLOS) channels have large multipath delay spreads and can utilize many different pointing angles to provide propagation links. At 60 GHz, there is more path loss and smaller delay spreads. Power delay profiles PDPs were measured at every individual pointing angle for each TX and RX location, and integrating each of the PDPs to obtain received power as a function of pointing angle. The result shows that the mean RMS delay spread varies between 7.2 ns and 74.4 ns for 60 GHz and 28 GHz respectively in NLOS scenario.
DESIGN OF A COMPACT CIRCULAR MICROSTRIP PATCH ANTENNA FOR WLAN APPLICATIONS pijans
This paper presents the design of a compact circular microstrip patch antenna for WLAN applications which covers the band 5.15 to 5.825 GHz. The antenna is designed using 1.4mm thick FR-4 (lossy)substrate with relative permittivity 4.4 and a microstrip line feed is used. The radius of the circular patch is chosen as 7.62mm. To reduce the size and enhance the performance of the proposed antenna, a circular slot is loaded on circular patch and a square slot is etched on the ground plane of dimension 30mm×30mm. Design of the antenna is carried out using CST Microsoft Studio Sonimulation Software. The proposed antenna resonates at 5.5 GHz with a wider bandwidth of 702 MHz and it provides low return loss of -31.58 dB, good gain of 3.23 dB and directivity of 4.28 dBi and high efficiency of around 79% against the resonance frequency. The geometry of the proposed circular antenna with reduced size and its various performance parameters such as return loss, bandwidth, VSWR, gain, directivity, efficiency and radiation pattern plots are presented and discussed.
Energy-efficient user association mechanism enabling fully hybrid spectrum sh...TELKOMNIKA JOURNAL
Spectrum sharing (SS) is a promising solution to enhance spectrum utilization in future cellular
systems. Reducing the energy consumption in cellular networks has recently earned tremendous attention
from diverse stakeholders (i.e., vendors, mobile network operators (MNOs), and government) to decrease
the CO2 emissions and thus introducing an environment-friendly wireless communication. Therefore,
in this paper, joint energy-efficient user association (UA) mechanism and fully hybrid spectrum sharing
(EE-FHSS) approach is proposed considering the quality of experience QoE (i.e., data rate) as the main
constraint. In this approach, the spectrum available in the high and low frequencies (28 and 73 GHz) is
sliced into three portions (licensed, semi-shared, and fully-shared) aims to serve the users (UEs)
that belong to four operators in an integrated and hybrid manner. The performance of the proposed
QoE-Based EE UA-FHSS is compared with the well-known maximum signal-to-interference-plus-noise
ratio (max-SINR UA-FHSS). Numerical results show that remarkable enhancement in terms of EE for
the four participating operators can be achieved while maintaining a high degree of QoE to the UEs.
A Novel Routing Strategy Towards Achieving Ultra-Low End-to-End Latency in 6G...IJCNCJournal
Compared to 5G, 6G networks will demand even more ambitious reduction in endto-end latency for packet communication. Recent attempts at breaking the barrier of end-to-end millisecond latencies have focused on re-engineering networks using a hybrid approach consisting of an optical-fiber based backbone network architecture coupled with high-speed wireless networks to connect end-devices to the backbone network. In our approach, a wide area network (WAN) is considered with a high-speed optical fiber grid network as its backbone. After messages from a source node enter the backbone network through a local wireless network, these are delivered very fast to an access point in the backbone network closest to the destination node, followed by its transfer to the local wireless network for delivery to the destination node. We propose a novel routing strategy which is based on distributing the messages in the network in such a way that the average queuing delay of the messages through the backbone network is minimized, and also the route discovery time at each router in the backbone network is drastically reduced. Also, multiple messages destined towards a particular destination router in the backbone network are packed together to form a mailbag, allowing further reductions in processing overheads at intermediate routers and pipelining of mailbag formation and route discovery operations in each router. The performance of the proposed approach green based on these ideas has been theoretically analyzed and then simulated using the ns-3 simulator. Our results show that the average end-to-end latency is less than 380 µs (with only 46-79 µs within the backbone network under varying traffic conditions) for a 1 KB packet size, when using a 500 Gbps optical fiber based backbone network laid over a 15 Km × 15 Km area, a 50 Mbps uplink channel from the source to the backbone network, and a 1 Gbps downlink channel from the backbone network to the destination. The significant reduction in end-to-end latency as compared to existing routing solutions clearly demonstrates the potential of our proposed routing strategy for meeting the ultra-low latency requirements of current 5G and future 6G networks, particularly for mobile edge computing (MEC) application scenarios.
Design and software implementation of radio frequency satellite link based on...TELKOMNIKA JOURNAL
The satellite communication providea utilization of radio frequency links. Specific frequencies are dedicated for satellite correspondences through global administrative and coordination procedures which keeps impedance amongframeworks. Over typical work, the satellite receives uplinked indicator fromearth. Progressions its frequency marginally will keep away from self-intervention then re-transmits signal ahead the downlink on the land. Pathloss depicts characteristic Propagate outside the sending signal front as it goes bythe space. A software defined radio (SDR) is a flexible technology that aimsto replace all hardware by software to enables the design of adaptive communications systems such as changing frequencies, modulation schemes and data rates. Applied to small satellites, some of the implications areincreased data through put when down-linking or up-linking by varying communications parameters and making use of one hardware design and implementation for communicating for many missions, just by updating the software. Therefore, development time for small satellite communication systems can be reduced in the future. This paper analyzes, design and software implementation of radio frequency satellite communications links under noisy channels such as phase/frequency offsets and noise temperature. Modulation schemes such as 64QAM system is used based on Matlab tools to implement the results. Obtained results shows a good response that get the goal from the paper.
Magnetic resonance coupling for 5G WPT applicationsjournalBEEI
Inductive Wireless Power Transfer (IWPT) is the most popular and common technology for the resonance coupling power transfer. However, in 2007 it has experimentally demonstrated by a research group from Massachusets Institute of Technology (MIT) that WPT can be improved by using Magnetic Resonance Coupling Wireless Power Transfer (MRC WPT) in terms of the coupling distance and efficiency. Furthermore, by exploiting the unused, high-frequency mm-wave band which are ranging from 3~300 GHz frequency band, the next 5G generations of wireless networks will be able to support a higher number of devices with the increasing data rate, higher energy efficiency and also compatible with the previous technology. In this work, a square planar inductor with the dimension of 6.1 x 6.1 mm is designed, and the resonators have the same self-resonance frequency at 14 GHz. The coil resonators have been laid on Silicon and Oxide substrate to reduce the loss in the design. From the CST software simulation and the analytical model in MATLAB software, it has been shown that the MRC WPT design has improved the performance of IWPT design by 40% power transfer efficiency. MRC WPT design also has larger H-Field value which is 705.5 A/m, as compared to the IWPT design which has only 285.6 A/m when both Transmitter(Tx) and Reciever(RX) is at 0.3 mm coupling distance.
Capacity Improvement of Cellular System Using Fractional Frequency Reuse (FFR)IJEEE
Today wireless communication is mostly used rather than wired communication, due to remote location reach ability, less fault occurrence, less time to commissioning and low cost etc. But wireless network has less frequency spectrum to cover the whole world. To improve the capacity of cellular system in a limited spectrum without major technological changes, frequency is reused in cells. But it offers interferences mostly for cell edge users. To solve the problem of spectral congestion and user capacity, fractional frequency reuse is used. This paper gives idea about different frequency reuse factors, fractional frequency reuse and super cell with sectoring to improve the capacity of cellular system.
Modelling and QoS-Achieving Solution in full-duplex Cellular SystemsIJCNCJournal
The global bandwidth scarcity and the ever-growing demand for fast wireless services have motivated the quest for new techniques that enhance the spectral efficiency (SE) of wireless systems. Most conventional SE increasing methods (e.g., adaptive modulation and coding) have already been exhausted. Single-channel full-duplex (SCFD) communication is a new attractive approach in which each node may simultaneously receive and transmit over the same frequency channel, and thus, it has the potential to double the current SE figures. In this paper, we derive a model for the signal-to-interference-plus-noise ratio (SINR) in a SCFD-based cellular system with imperfect self-interference cancellation. Furthermore, given a set of uplink and downlink quality of service requirements, we answer the following two fundamental questions. First, is this set achievable in the SCFD-based cellular system? Second, if the given set is achievable, what is the optimal achieving policy? To that end, we provide a unified model for the SCFD-based cellular system, and give insights in the matrix of interference channel gains. Simulation results suggest that depending on the locations of the users, a combination of full-duplex and half-duplex modes over the whole network is more favourable policy
Enhancement algorithm for reverse loop technique on planar reverse loop antennaTELKOMNIKA JOURNAL
Finding a trade-off balance between wireless transfer efficiency (WTE) and distance is a key
issue in wireless energy transfer (WET). This paper presents a method of reducing the radical alteration in
WTE versus distance, by using a reverse loop technique on planar reverse loop antenna (PRLA).
The design focuses on 13.56 MHz Near Field Communication (NFC). The first stage uses mathematical
modelling, based on an analytical approach, to determine the size of the reverse loop using Matlab.
The proposed model predicts the size of the reverse loop to stabilize the WTE at a closer distance.
Next, full-wave electromagnetic simulations are applied, using the computer simulation technology (CST)
MICROWAVE STUDIO®, to determine the WTE effect with distance changes with mismatch condition.
Planar loop antennas (PLAs) are fabricated on glass-reinforced epoxy laminated sheets (FR4).
A validation of the simulation result in a real test scenario, using these PLAs and PRLA, confirms
a stability enhancement in WTE at closer distance using the reverse loop technique, compared to
conventional designs.
Performance of modeling wireless networks in realistic environmentCSCJournals
A wireless network is realized by mobile devices which communicate over radio channels. Since, experiments of real life problem with real devices are very difficult, simulation is used very often. Among many other important properties that have to be defined for simulative experiments, the mobility model and the radio propagation model have to be selected carefully. Both have strong impact on the performance of mobile wireless networks, e.g., the performance of routing protocols varies with these models. There are many mobility and radio propagation models proposed in literature. Each of them was developed with different objectives and is not suited for every physical scenario. The radio propagation models used in common wireless network simulators, in general researcher consider simple radio propagation models and neglect obstacles in the propagation environment. In this paper, we study the performance of wireless networks simulation by consider different Radio propagation models with considering obstacles in the propagation environment. In this paper we analyzed the performance of wireless networks by OPNET Modeler .In this paper we quantify the parameters such as throughput, packet received attenuation.
The study evaluated interference in a dense heterogeneous network using third-generation universal mobile telecommunication systems (UMTS) and fourth-generation long term evolution (LTE) networks LTE. The UMTs/LTE heterogeneous network determines the level of interference when the two communication systems coexist and how to improve the network by migrating from UMTs to LTE, which has a faster download speed and larger capacity. Techno lite 8 on third generation (3G) and Infinix Pro 6 on fourth generation (4G) were used to measure network the received signal strength (RSS) during site investigation. UE interference was detected and traced using a spectrum analyzer. UMTS and LTE path loss exponents are 2.6 and 3.2. Shannon's capacity theorem calculated LTE and UMTS capacity. When signal to interference and noise ratio (SINR) was used as a quality of service (QoS) indicator, MATLAB channel capacity plots did not match Shannon's due to neighboring interference. UMTS had an R2 of 0.54 and LTE 0.57 for the Shannon channel capacity equation. Adjacent channel interference (ACI) user devices reduce network capacity, lowering QoS for other customers.
Compared to wireless deployment in areas with different environmentseIJECEIAES
In the mobile phone system, it is highly desirable to estimate the loss of the track not only to improve performance but also to achieve an accurate estimate of financial feasibility; the inaccurate estimate of track loss either leads to performance degradation or increased cost. Various models have been introduced to accurately estimate the path loss. One of these models is the Okomura / Hata model, which is recommended for estimating path loss in cellular systems that use micro cells. This system is suitable for use in a variety of environments. This study examines the comparison of path loss models for statistical analysis derived from experimental data collected in urban and suburban areas at frequencies of 150-1500 MHz’s The results of the measurements were used to develop path loss models in urban and suburban areas. The results showed that Pathloss increases in urban areas respectively.
Effect on Channel Capacity of Multi-User MIMO System in Crowded AreaIJEEE
Multiple-Input Multiple-Output (MIMO) and Multi-User
MIMO (MU-MIMO) systems have been expected to
improve the channel capacity over a limited bandwidth of
existing networks.
Coverage enhancements of vehicles users using mobile stations at 5G cellular ...nooriasukmaningtyas
High mobility requirements are one of the challenges face fifth-generation wireless (5G) cellular networks by providing acceptable wireless services to users traveling at speed up to 350 km/h. This paper presents a new scenario to increase the bit rate and coverage for passengers that use the vehicles for traveling through the installation a mobile station (MS) on these vehicles to provide a high-quality service to users. Based on signal to noise ratio (SNR’s) mathematical derivation and the outage probability of the user link, the proposed system is evaluated. Numerical results indicate an enhancement for users who received signal strength (RSS) from (-72 to -55) dBm and (15 to 38) Mbps in bit rate. Moreover, their number of users increased by proposed system adoption.
Signal Strength Evaluation of a 3G Network in Owerri Metropolis Using Path Lo...Onyebuchi nosiri
Abstract: In this work, the path loss and the received signal strength of a 3G network at 2.1GHz was evaluated to determine its performance within the Owerri metropolis. Various measuring equipment such as Transmission Evaluation and Monitoring System (TEMS 11), Global positioning system (BU353 GPS) and laptop were deployed for the drive test within the selected urban and sub-urban regions. From the data collected, Owerri sub-urban region showed poor received signal power level compared to the Owerri urban region. The path loss exponents computed for the Owerri urban and sub-urban regions are 3.24 and 4.34 respectively, the mean square error was evaluated as 1.96 and 1.68. The result obtained showed deviations between the compared existing models (Hata and Cost 231) and the proposed models. However, the slope of the Hata plot was relatively close in comparison to the proposed model than that of Cost 231; hence, the proposed model was best suited for the environment followed by the Hata model.
Signal Strength Evaluation of a 3G Network in Owerri Metropolis Using Path Lo...Onyebuchi nosiri
Abstract: In this work, the path loss and the received signal strength of a 3G network at 2.1GHz was evaluated to determine its performance within the Owerri metropolis. Various measuring equipment such as Transmission Evaluation and Monitoring System (TEMS 11), Global positioning system (BU353 GPS) and laptop were deployed for the drive test within the selected urban and sub-urban regions. From the data collected, Owerri sub-urban region showed poor received signal power level compared to the Owerri urban region. The path loss exponents computed for the Owerri urban and sub-urban regions are 3.24 and 4.34 respectively, the mean square error was evaluated as 1.96 and 1.68. The result obtained showed deviations between the compared existing models (Hata and Cost 231) and the proposed models. However, the slope of the Hata plot was relatively close in comparison to the proposed model than that of Cost 231; hence, the proposed model was best suited for the environment followed by the Hata model.
Advanced antenna techniques and high order sectorization with novel network t...ijwmn
Mobile operators commonly use macro cells with trad
itional wide beam antennas for wider coverage in th
e
cell, but future capacity demands cannot be achieve
d by using them only. It is required to achieve max
imum
practical capacity from macro cells by employing hi
gher order sectorization and by utilizing all possi
ble
antenna solutions including smart antennas. This pa
per presents enhanced tessellation for 6-sector sit
es
and proposes novel layout for 12-sector sites. The
main target of this paper is to compare the perform
ance
of conventional wide beam antenna, switched beam sm
art antenna, adaptive beam antenna and different
network layouts in terms of offering better receive
d signal quality and user throughput. Splitting mac
ro cell
into smaller micro or pico cells can improve the ca
pacity of network, but this paper highlights the
importance of higher order sectorization and advanc
e antenna techniques to attain high Signal to
Interference plus Noise Ratio (SINR), along with im
proved network capacity. Monte Carlo simulations a
t
system level were done for Dual Cell High Speed Dow
nlink Packet Access (DC-HSDPA) technology with
multiple (five) users per Transmission Time Interva
l (TTI) at different Intersite Distance (ISD). The
obtained results validate and estimate the gain of
using smart antennas and higher order sectorization
with
proposed network layout.
Similar to Proposed Model for Interference Estimation in Code Division Multiple Access (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
In this paper, snake optimization algorithm (SOA) is used to find the optimal gains of an enhanced controller for controlling congestion problem in computer networks. M-file and Simulink platform is adopted to evaluate the response of the active queue management (AQM) system, a comparison with two classical controllers is done, all tuned gains of controllers are obtained using SOA method and the fitness function chose to monitor the system performance is the integral time absolute error (ITAE). Transient analysis and robust analysis is used to show the proposed controller performance, two robustness tests are applied to the AQM system, one is done by varying the size of queue value in different period and the other test is done by changing the number of transmission control protocol (TCP) sessions with a value of ± 20% from its original value. The simulation results reflect a stable and robust behavior and best performance is appeared clearly to achieve the desired queue size without any noise or any transmission problems.
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.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
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Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
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interferers power along the circumcircle of the grid-shaping polygon. In [10], proposed an
analytical execution for the estimation of the capacity of WCDMA system with effect of Co-
Channel Interference (CCI) and the performance analysis is carried out in terms of sectorization,
power control, and voice activity services.
However, the main goal of this paper is to characterize and evaluate the average other-
cell interference caused by users in different location at busy and show how the interference
affected with path loss exponent, then exhibit effect of interference on the capacity of cellular
systems. This will be accomplished through the derivation of a mathematical model to determine
the number of users contributing to the inter-cell interference and using two slop path loss
model.
2. Proposed Model for Average Number of Interference
Assume that each cell in the typical cellular communication system illustrated in
Figure 1, having an area of Ac around a cellular base station transceiver. For mathematical
convenience, the hexagonal shape of the cell is approximated by a circle with Rc as the
maximum cell radius. In each cell, the area covered by the ring of radius r, with small width dr
will be )2( rdr . When the cell is not fully coveraged by the base station, the fraction of the
coverage within an area in which the transmitted signal strength from a mobile unit has the
probability to contribute in traffic and interference is then the sum of the area associated with all
thin rings from radius 0 to Rc multiplied by the corresponding coverage percentages pc(r).
)1()(2
0
cR
r
cc drrprA (1)
Figure 1. Cellular circular configuration
In this work, the approach used to characterize any cell state in the network depends on
the number of users existing inside that cell. The average number of mobile units located inside
the ring dr at time t = 0, can be found from the area covered by the ring )2( rdr , and the
average mobile density that represent the number of mobiles per unit area:
)2()()(2 2
0
mcc
R
r
mc rpRdrrprN
c
(2)
where N is the average number of mobile units and ρm is the average mobile density mobile
units/km2. For purposes of this paper, a fully covered cell will be assumed; hence, the coverage
percentages pc(r) will assumed to be equal to 1 for worst case truly representation. Assuming
that ( u ) is the average mobile unit speed in km/h, then the distance dr can be given as
( dtudr ), and the average number of mobiles entering the cell coverage area Ac within a
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Proposed Model for Interference Estimation in Code Division... (Dalal Kanaan Taher)
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time dt, will be equal to the number of mobiles located within a ring of width dr and the average
mobile density that represent the number of mobile units per unit area:
)3(2
0
t
t
m dturN (3)
The average number of mobiles entering the whole cell area during a time period of length T
can be given as:
)4(2
0
T
t
mc dtuRN (4)
Assuming that probability of mobile stations entering the area Ac is equal to m1, and
probability of mobile units leaving the area Ac is equal to m2, the average number of mobiles
crossing the area Ac during a time period of length T and contributing to the total traffic and
interference will be:
)5(2)1(
0
2
T
t
mc dtuRmN (5)
In up-link, any user within the coverage area of any cell is said to be active if the ratio of
received energy per chip to interference plus noise density ratio (𝐸 𝑏/ 𝑁𝑡) at the base station is
sufficient. The Eb/Nt ratio represents the signal-to-interference ratio (SIR) that is required from
the mobile to have reliable link.
3. Propagation and Interference Modeling
3.1. Power Exponent Propagation Model
A radio propagation model is a mathematical/empirical formulation for characterizing
radio wave propagation as a function of frequency, distance and other environmental
conditions [11]. The Log-distance path loss model is used here as it takes in to consideration
the decrease in received power due to the distance, as well as the energy loss in terms of an
empirical path loss constant (n) [12]. The interference factor is depending on path loss exponent
(n), so practical measurements in some ASIACELL sites in the city of Baghdad are taken to
determine the exact value of (𝑛). Figure 2 shows the map of the drive test for one of the
ASIACELL sites at which the received power had been measured at different distance (in
meter). Then the accurate power exponent value is determined by the least mean square error
(LMS) approach which is a numerical optimization schemes that can be applied to reduce the
error in calculating the power exponent value. The formula is used from [13] as:
K
1i
22
K
1i
)()(measured)(=F(n) iriri dpcalculateddpe
K
i
K
i o
i
orrii
d
d
ndppenF
1 1
2
10
2
log10)()()( (6)
where (𝑒𝑖) is the error between the measured and calculated values of the received signal
power, and (𝑝𝑟𝑖) is the received power as measured in 𝑖𝑡ℎ measurement in (dBm) at the distance
(𝑑𝑖). Table 1 shows the obtained measurements at different distances from the base station of
three sites in the city of Baghdad.
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Table 1. Empirical Data for Three Sites (Practical Measurements)
Figure 2. Site 1 in the city of Baghdad
Applying (6) using the obtained measurements for site_1:
2
1
222
)19.46.5567()57.26.554.63()96.16.551.56[()()( nnnenF
K
i
i
])21.66.556.71()32.56.552.69()78.46.557.68( 222
nnn
By differentiating 𝐹(𝑛) relative to (𝑛) and setting it to zero yields the values of (𝑛).The
values of n for the other two sites were calculated by the same method. Power exponent value
(𝑛)for site_1=2.6064, Power exponent value for site_2=2.6611, Power exponent value for
site_3=2.8804. So, the average value of the power exponent value was calculated
to be 2.7159.
3.2. Interference Modeling
A typical cellular configuration illustrated in Figure 3 is considered. All cells in the
system are identical and a base stations of omnidirectional architecture are assumed to be
located at the center of each cell. The distance between the reference cell A (at the center of
the figure) and the center of any one of the interfering cells is denoted as D. For the moment, a
single reference cell and one interfering cell will be considered for interference analysis at up-
link case. Let the mobile user j be located at the reference cell A at a distance of ro from its
serving base station, and the mobile i be located at interfering cell B at a distance (di ) from its
serving base station.
Site 1 Site 2 Site 3
𝑑 𝑜= 36.6 𝑝𝑟(𝑑 𝑜) = -55.6 𝑑 𝑜 = 58.1 𝑝𝑟(𝑑 𝑜) = -61.5 𝑑 𝑜= 46.8 𝑝𝑟(𝑑 𝑜) = -65.7
(𝑑𝑖) pri (𝑑𝑖) pri (𝑑𝑖) pri
57.5 -56.1 83.14 -67.2 52.43 -68.8
66.2 -63.4 110.3 -68.7 69.1 -69.4
96.29 -67 126.7 -69.3 85.4 -72.1
110.1 -68.7 153.8 -71.2 104.9 -74.4
124.7 -69.2 175.4 -75.5 125.4 -78
152.9 -71.6 185.6 -76.5 136.2 -80.9
177.8 -73.6 201 -76.7 177 -81
197.6 -74.5 232.4 -77.3 186.1 -86
210.9 -74.8 252.9 -78 200.1 -86.4
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Proposed Model for Interference Estimation in Code Division... (Dalal Kanaan Taher)
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Figure 3. Interfering and interfered cells representation
The power of the mobile i received at its serving base station (pri) can be determined by
using Two-slop path loss propagation model as:
tn
ii
ri p
gdd
K
p
1)(
(7)
where (Pt) is the power transmitted by the mobile user i to its serving base station, K is a
constant that depends on operating frequency, antenna heights and gains of both base station
and mobile, and (α) is the propagation path loss exponent (ranges from 2-4), (n) is extra path
loss exponent which is typically range (2-6). And ( g ) is break point distance )4( mb hhg
where hb is base station height, hm is mobile station height and ( λ ) is wave length [14]. The
power transmitted by the i-th user at the interfering cell (B) will be received by all other users
located at the same cell. Therefore, it will be the user contribution in intra-cell interference
(same cell interference) that is proportional to its distance. The signal transmitted by the user i
will be also received simultaneously by other base stations operating in the network causing an
instantaneous co-channel interference (inter-cell interference). The interference Pi caused by
user i to the reference cell (A) at distance ri can be expressed as:
tn
ii
i p
grr
K
P
1)(
(8)
]1)[(
n
iirit gddPPK
rin
ii
n
ii
i P
grr
gdd
P
1)(
1)(
(9)
For identical equally loaded cells, the average inter cell interference to the reference cell
from all mobile users in all of the interfering cells in the first-tier of co-channel cells can be
expressed as:
)(6))((
1 1
i
I
n
N
i
itotalii PENPrP
(10)
D
ri
di
A
B
User i
User jro
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where Io=6 is the number of co-channel cells in the first tire of the system and E(pi) represents
the average expected power received from the i-th interfering mobile station that depends on
user location with respect to the reference cell. The desired user SIR can be defined as the ratio
of the averaged received power to the sum of interfering received signal power. Therefore, the
signal-to-interference ratio (SIR) of any mobile user j at the reference cell can be given as:
thermalerra
rp
thermalMA
rp
total
rp
j
NII
rPG
NI
rPG
I
rPG
SIR
intint
)()()(
)(
(11)
where Pr(ro) is the power received by the reference base station from the desired user j that is
located at a distance ro, Gp is processing gain (Gp=system band width / data rate),I MA is the
multiple access interference power that includes the intra-cell interference and the inter-cell
interference, and Nthermal is the thermal noise.
)(6)1(
)(
)()1(
)(
)(
1
iir
rp
i
m
i
ir
rp
j
rPENPM
rPG
rPPM
rPG
SIR
(12)
)(61
)(1
ii
j
rpEN
SIRG
M
(13)
where (M) is the system capacity which is equivalent to the number of users the system can
support While maintaining a good signal to interference ratio [15].
4. Simulation
Matlab simulation is used to estimate interference factor and its effect on capacity. The
process of simulation for CDMA systems is taken into account the traffic in cell at busy time, the
environment of signal propagation (propagation loss exponent) and distribution of users in the
cell. The basic parameters used for the simulation are presented in Table 2.
Table 2. Simulation Parameters
4.1. Results and Analysis
Figure 4 illustrate result of the average interference and the variance determination with
the number of users ( m ) in a single cell, distance D between the interfering cell and reference
cell equal to (2 Km) and propagation model of Baghdad city (2.71). the plot shows when the
number of user contribution in interference increases, lead it to increase in interference
experienced by the users in the desired cell, this is due to the fact that the average interference
is a summation of interferences from each user.
Figure 5 show average other-cell interference generated by interfering user increases
with (di) and effect extra path loss exponent on interference, where the different values of extra
propagation path loss exponent (n) are used. Due to fact that, the users at cell center and users
at the boundary of cell generate different interference to neighboring cells. In order to obtain
purpose (SIR), mobile users at the boundary using the highest transmit powers, Therefore,
parameter value parameter value parameter value
Cell Radius
(Rc )
1 Km
Mobile station
height ( mh )
1.5 m
Base-station height
( bh )
15 m
Speed of Mobile
( u )
60 Km/hr
Time period
(T)
8-10 hr
Signal-to
interference ratio
(SIR)
8 dB
Power exponent
(α)
2
Mobile density
(ρm)
10/Km2
Processing gain (G) 128
Extra path loss (n),
Baghdad city
2.71
Probability mobile
leaving (m2)
0.4 Carrier Frequency 2100 MHz
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highest interference is caused to the surrounding cells, that limiting the number of acceptable
users in the reference cell.
Figure 4. Plot of other-cell interference factor versus number of users, D=2 Km
Figure 5. Average Interference VS user distance with different (n), R=1 Km
The Figure 6 display a sacrificial value of capacity (number of users that the cellular
system can uphold without the quality of service any user falls under the minimum required).
The capacity for this case is calculate for using different propagation exponent and taking into
account interference factor, threshold SIR and processing gain. The result show that When
interfering user near to center of its’ cell, then gives low value of interference for neighboring
cell, so the desire system can support nearly (41) users without losing a call, and when the user
at boundary of its’ in interfering cell, the desired cell can hold (37) users at propagation path loss
exponent of Baghdad (n=2.71). This show the inversely proportional between interference and
capacity.
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TELKOMNIKA Vol. 16, No. 6, December 2018: 2549-2556
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Figure 6. Illustration the capacity of system
5. Conclusion
Mathematical model is proposed for calculation number of interference user. Then,
these users are populated on a single interfering cell, it is concluded that increasing the number
of user caused the rise the interference factor. Also the analysis showed that users at a
boundary cell generate more interference than those close to the base station. By using the fact
that the interference factor depends on the location of each user and its effect on capacity is
plotted. Model of Baghdad city and its effect on interference factor is estimated, after that, the
effect of different path loss on interference ratio is shown that greater path loss exponent
denoted decrease in interference factor.
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