This document analyzes the bit error rate (BER) of two-user power-domain non-orthogonal multiple access (NOMA) systems using successive interference cancellation receivers over Rayleigh fading channels. It derives closed-form expressions for the BER in single-input single-output and multiple-input multiple-output NOMA systems. The analysis considers two categories of multiuser superposition transmission and verifies the analytical results through Monte Carlo simulation.
FUZZY LOGIC-BASED EFFICIENT MESSAGE ROUTE SELECTION METHOD TO PROLONG THE NET...IJCNCJournal
- The document discusses a fuzzy logic-based method for efficient message routing in wireless sensor networks to prolong the network lifetime. It aims to balance energy load across nodes by selectively tagging nodes at risk of energy exhaustion and rerouting messages around them.
- It proposes using fuzzy logic to evaluate nodes based on their potential importance, energy level, and event occurrence frequency to determine tagging. Tagged nodes avoid routing traffic but still detect and generate reports.
- The method was tested by applying it to a probabilistic voting-based filtering security scheme and was shown to improve energy efficiency, node survival rate, and report transmission success compared to not tagging nodes.
IMPLEMENTATION OF BIOLOGICAL ROUTING PROTOCOL IN TUNNEL WIRELESS SENSOR NETWO...ijwmn
The document describes a new biological routing protocol called Biological Tunnel Routing Protocol (BioTROP) for Tunnel Wireless Sensor Networks (TWSN). BioTROP uses concepts from ant colony behavior and optimal forwarding calculations to determine the best next hop neighbor for packet transmission. It was tested on a 7 node TelosB sensor network in a tunnel, where over 70% of transmitted data packets were successfully delivered to the base station. BioTROP employs a cross-layer design between the physical and network layers to select next hops based on metrics like signal strength, link quality, and remaining power from the physical layer. It consists of routing management and neighborhood management modules to determine optimal routes and maintain neighbor tables.
PERFORMANCE STUDY AND SIMULATION OF AN ANYCAST PROTOCOL FOR WIRELESS MOBILE A...ijwmn
This paper conducts a detailed simulation study of stateless anycast routing in a mobile wireless ad hoc
network. The model covers all the fundamental aspects of such networks with a routing mechanism using
a scheme of orientation-dependent inter-node communication links. The simulation system Winsim is used
which explicitly represents parallelism of events and processes in the network. The purpose of these
simulations is to investigate the effect of node’s maximum speed, and different TTL over the network
performance under two different scenarios. Simulation study investigates five practically important
performance metrics of a wireless mobile ad hoc network and shows the dependence of this metrics on
the transmission radius, link availability, and maximal possible node speed
EFFECTS OF MAC PARAMETERS ON THE PERFORMANCE OF IEEE 802.11 DCF IN NS-3ijwmn
This paper presents the design procedure of the NS-3 script for WLAN that is organized according to the hierarchical manner of TCP/IP model. We configure all layers by using NS-3 model objects and set and modify the values used by objects to investigate the effects of MAC parameters (access mechanism, CWmin, CWmax and retry limit) on the performance metrics viz. packet delivery ratio, packet lost ratio, aggregated throughput, and average delay. The simulation results show that RTS/CTS access mechanism outperforms basic access mechanism in saturated state, whereas the MAC parameters have no significant impact on network performance in non-saturated state. A higher value of CWmin improves the aggregated throughput in expense of average delay. The tradeoff relationships among the performance metrics are also observed in results for the optimal values of MAC parameters. Our design procedure represents a good guideline for new NS-3 users to design and modify script and results greatly benefit the network design and management.
Flbra fuzzy logic based routing algorithm for indoor wireless sensor networksijcsit
Considering the context of building management systems with wireless sensor networks monitoring
environmental features, this paper presents a proposal of a Fuzzy Logic Based Routing Algorithm (FLBRA)
to determine the cost of each link and the identification of the best routes for packet forwarding. We
describe the parameters (Received Signal Strength Indicator - RSSI, Standard Deviation of the RSSI and
Packet Error Rate - PER) for the cost definition of each path, the sequence of identifying best routes and
the results obtained in simulation. As expected in this proposal, the simulation results showed an increase
in the packet delivery rate compared to RSSI-based forward protocol (RBF).
E NERGY - E FFICIENT P ATH C ONFIGURATION M ETHOD FOR DEF IN WSN Sijitjournal
In wireless sensor ne
tworks (WSNs), sensor nodes have stringent energy and computation requirements.
Since they are left unattended, an adversary can generate false report attacks through compromised nodes.
This would result in an increased number of verifications to filter th
ese reports, causing waste of scarce
energy resources. In this paper, we propose energy
-
efficient path configuration method for dynamic en
-
route filtering (EDEF), which uses fuzzy logic to select the forwarding node(s). In order to cater to
compromised nod
es and to detect and filter the false reports, we create alternative paths. Our proposed
method selects forwarding nodes based on the key content of neighbor nodes, the number of neighbor
nodes, and the residual energy. Auth
-
keys are distributed randomly f
rom the global key pool. Simulation
results demonstrate the effectiveness of our proposed method with up to 8.2% energy efficiency as
compared to the dynamic en
-
route filtering (DEF) scheme.
A fuzzy based congestion controller for control and balance congestion in gri...csandit
A Wireless Sensor Network (WSN) is deployed with a large number of sensors with limited
power supply in a wide geographically area. These sensors collect information depending on
application. The sensors transmit the data towards a base station called sink. Due to the
relatively high node density and source-to-sink communication pattern, congestion is a critical
issue in WSN. Congestion not only causes packet loss, but also leads to excessive energy
consumption as well as delay. To address this problem, in this paper we propose a new fuzzy
logic based mechanism to detect and control congestion in WSN. In the proposed approach, a
Monitor Node for each grid in congestion candidate region performs a fuzzy control to avoid
increasing congestion. Fuzzy controller’s inputs are continually fetched from the network by the
Monitor Node. Simulation results show that our approach has higher packet delivery ratio and
lower packet loss than existing approaches.
Modeling and Analysis of Two Node Network Model with Multiple States in Mobi...Editor IJCATR
In this work, the decision probability of the handoff are modeled and simulated for smaller bandwidths. The smaller
bandwidth is chosen just for simulation purposes and to demonstrate the applicability of the algorithm. The probability of handover
and probability of incorrect decision in the handover is modeled. Two nodes of the network are modeled and the probabilities of four
different states of the mobile node are also modeled. The results are presented for two cases with and without the probabilities of four
different states of the mobile nodes
FUZZY LOGIC-BASED EFFICIENT MESSAGE ROUTE SELECTION METHOD TO PROLONG THE NET...IJCNCJournal
- The document discusses a fuzzy logic-based method for efficient message routing in wireless sensor networks to prolong the network lifetime. It aims to balance energy load across nodes by selectively tagging nodes at risk of energy exhaustion and rerouting messages around them.
- It proposes using fuzzy logic to evaluate nodes based on their potential importance, energy level, and event occurrence frequency to determine tagging. Tagged nodes avoid routing traffic but still detect and generate reports.
- The method was tested by applying it to a probabilistic voting-based filtering security scheme and was shown to improve energy efficiency, node survival rate, and report transmission success compared to not tagging nodes.
IMPLEMENTATION OF BIOLOGICAL ROUTING PROTOCOL IN TUNNEL WIRELESS SENSOR NETWO...ijwmn
The document describes a new biological routing protocol called Biological Tunnel Routing Protocol (BioTROP) for Tunnel Wireless Sensor Networks (TWSN). BioTROP uses concepts from ant colony behavior and optimal forwarding calculations to determine the best next hop neighbor for packet transmission. It was tested on a 7 node TelosB sensor network in a tunnel, where over 70% of transmitted data packets were successfully delivered to the base station. BioTROP employs a cross-layer design between the physical and network layers to select next hops based on metrics like signal strength, link quality, and remaining power from the physical layer. It consists of routing management and neighborhood management modules to determine optimal routes and maintain neighbor tables.
PERFORMANCE STUDY AND SIMULATION OF AN ANYCAST PROTOCOL FOR WIRELESS MOBILE A...ijwmn
This paper conducts a detailed simulation study of stateless anycast routing in a mobile wireless ad hoc
network. The model covers all the fundamental aspects of such networks with a routing mechanism using
a scheme of orientation-dependent inter-node communication links. The simulation system Winsim is used
which explicitly represents parallelism of events and processes in the network. The purpose of these
simulations is to investigate the effect of node’s maximum speed, and different TTL over the network
performance under two different scenarios. Simulation study investigates five practically important
performance metrics of a wireless mobile ad hoc network and shows the dependence of this metrics on
the transmission radius, link availability, and maximal possible node speed
EFFECTS OF MAC PARAMETERS ON THE PERFORMANCE OF IEEE 802.11 DCF IN NS-3ijwmn
This paper presents the design procedure of the NS-3 script for WLAN that is organized according to the hierarchical manner of TCP/IP model. We configure all layers by using NS-3 model objects and set and modify the values used by objects to investigate the effects of MAC parameters (access mechanism, CWmin, CWmax and retry limit) on the performance metrics viz. packet delivery ratio, packet lost ratio, aggregated throughput, and average delay. The simulation results show that RTS/CTS access mechanism outperforms basic access mechanism in saturated state, whereas the MAC parameters have no significant impact on network performance in non-saturated state. A higher value of CWmin improves the aggregated throughput in expense of average delay. The tradeoff relationships among the performance metrics are also observed in results for the optimal values of MAC parameters. Our design procedure represents a good guideline for new NS-3 users to design and modify script and results greatly benefit the network design and management.
Flbra fuzzy logic based routing algorithm for indoor wireless sensor networksijcsit
Considering the context of building management systems with wireless sensor networks monitoring
environmental features, this paper presents a proposal of a Fuzzy Logic Based Routing Algorithm (FLBRA)
to determine the cost of each link and the identification of the best routes for packet forwarding. We
describe the parameters (Received Signal Strength Indicator - RSSI, Standard Deviation of the RSSI and
Packet Error Rate - PER) for the cost definition of each path, the sequence of identifying best routes and
the results obtained in simulation. As expected in this proposal, the simulation results showed an increase
in the packet delivery rate compared to RSSI-based forward protocol (RBF).
E NERGY - E FFICIENT P ATH C ONFIGURATION M ETHOD FOR DEF IN WSN Sijitjournal
In wireless sensor ne
tworks (WSNs), sensor nodes have stringent energy and computation requirements.
Since they are left unattended, an adversary can generate false report attacks through compromised nodes.
This would result in an increased number of verifications to filter th
ese reports, causing waste of scarce
energy resources. In this paper, we propose energy
-
efficient path configuration method for dynamic en
-
route filtering (EDEF), which uses fuzzy logic to select the forwarding node(s). In order to cater to
compromised nod
es and to detect and filter the false reports, we create alternative paths. Our proposed
method selects forwarding nodes based on the key content of neighbor nodes, the number of neighbor
nodes, and the residual energy. Auth
-
keys are distributed randomly f
rom the global key pool. Simulation
results demonstrate the effectiveness of our proposed method with up to 8.2% energy efficiency as
compared to the dynamic en
-
route filtering (DEF) scheme.
A fuzzy based congestion controller for control and balance congestion in gri...csandit
A Wireless Sensor Network (WSN) is deployed with a large number of sensors with limited
power supply in a wide geographically area. These sensors collect information depending on
application. The sensors transmit the data towards a base station called sink. Due to the
relatively high node density and source-to-sink communication pattern, congestion is a critical
issue in WSN. Congestion not only causes packet loss, but also leads to excessive energy
consumption as well as delay. To address this problem, in this paper we propose a new fuzzy
logic based mechanism to detect and control congestion in WSN. In the proposed approach, a
Monitor Node for each grid in congestion candidate region performs a fuzzy control to avoid
increasing congestion. Fuzzy controller’s inputs are continually fetched from the network by the
Monitor Node. Simulation results show that our approach has higher packet delivery ratio and
lower packet loss than existing approaches.
Modeling and Analysis of Two Node Network Model with Multiple States in Mobi...Editor IJCATR
In this work, the decision probability of the handoff are modeled and simulated for smaller bandwidths. The smaller
bandwidth is chosen just for simulation purposes and to demonstrate the applicability of the algorithm. The probability of handover
and probability of incorrect decision in the handover is modeled. Two nodes of the network are modeled and the probabilities of four
different states of the mobile node are also modeled. The results are presented for two cases with and without the probabilities of four
different states of the mobile nodes
Comparison of energy efficient data transmission approaches for flat wireless...ijassn
In this paper we have analyzed energy efficient neighbour selection algorithms for routing in wireless
sensor networks. Since energy saving or consumption is an important aspect of wireless sensor networks,
its precise usage is highly desirable both for the faithful performance of network and to increase the
network life time. For this work, we have considered a flat network topology where every node has the
same responsibility and capability. We have compared two energy efficient algorithms and analyzed their
performances when all sensor nodes in a network have either homogeneous or heterogeneous energy with
increase in number of nodes, time rounds and node failures.
INCREASE THE LIFETIME OF WIRELESS SENSOR NETWORKS USING HIERARCHICAL CLUSTERI...ijwmn
Wireless sensor networks consist of hundreds or thousands of nodes with limited energy. Since the life time
of each sensor is equivalent to the battery life, the energy issue is considered as a major challenge.
Clustering has been proposed as a strategy to extend the lifetime of wireless sensor networks. Cluster size,
number of Cluster head per cluster and the selection of cluster head are considered as important factors in
clustering. In this research by studying LEACH algorithm and optimized algorithms of this protocol and by
evaluating the strengths and weaknesses, a new algorithm based on hierarchical clustering to increase the
lifetime of the sensor network is proposed. In this study, with a special mechanism the environment of
network is layered and the optimal number of cluster head in each layer is selected and then recruit for the
formation of clusters in the same layer by controlling the topology of the clusters is done independently.
Then the data is sent through the by cluster heads through the multi- stage to the main station. Simulation
results show that the above mentioned method increases the life time about 70% compared to the LEACH.
Introducing a novel fault tolerant routing protocol in wireless sensor networ...ijcsit
Although routing is one of the key network issues, the challenges facing WSN makes the subject even more
demanding. In this study, we propose a novel fault tolerant routing protocol in wireless sensor networks
using fuzzy logic. We approach the problem by breaking it down into two parts. The first sub problem is
designing a routing module and the second one retrofitting the designed module in a way that answering to
these two sub problems leads to the final solution of the main problem. To deal with the first stage, by using
fuzzy logic, we design a routing module; then for the second stage, the module enters fault tolerant routing
in order that it be tolerant against routing faults. In this study, the term "network failure" is figuratively
equal to "node failure".
A novel defence scheme against selfish Node attack in manetijcsa
This document proposes a new intrusion detection system (IDS) algorithm to defend against selfish node attacks in mobile ad hoc networks (MANETs). Selfish nodes flood the network with false information and drop packets from other nodes. The proposed IDS identifies selfish node behavior and blocks their activities. Simulation results show the IDS enhances network performance from negligible to 92% and prevents infection from attacks. The IDS is integrated with the AODV routing protocol to detect and eliminate selfish nodes within its transmission range.
Effective Path Identification Protocol for Wireless Mesh NetworksIDES Editor
Wireless Mesh Networks (WMNs) have emerged as
a key technology for next-generation wireless networking.
Routing is a key factor for transfer of packets from source to
destination. SrcRR is widely used protocol for transferring
packets from source to destination. This protocol often uses
Dijkstra’s algorithm on its link state database to find the next
alternative path to the destination when ever the ETX metric
of the link changes.This is a time consuming process if the
ETX metric of the links are changing frequently. So this paper
eliminates the use of Dijkistra’s algorithm and uses the a
search operation for finding the best paths.
A black-hole attack in the Mobile Ad-hoc NETwork (MANET) is an attack occurs due to malicious nodes,
which attracts the data packets by falsely advertising a fresh route to the destination. In this paper, we
present a clustering approach in Ad-hoc On-demand Distance Vector (AODV) routing protocol for the
detection and prevention of black-hole attack in MANETs. In this approach every member of the cluster will
ping once to the cluster head, to detect the peculiar difference between the number of data packets received
and forwarded by the node. If anomalousness is perceived, all the nodes will obscure the malicious nodes
from the network.
A new method for controlling and maintainingIJCNCJournal
Topology Control is an essential technique in a wireless sensor network to extend the operational time of
the sensor nodes. The goal of this technique is to maintain network connectivity and optimize performance
metrics such as network lifetime and throughput. In this paper we presented a new method for controlling
and maintaining topology in wireless sensor networks that show some improvement over the state of art
methods. The results are analyzed based on objective criteria.
The document summarizes an Efficient Position-Based Opportunistic Routing (EPOR) protocol proposed for mobile ad hoc networks. EPOR takes advantage of geographic routing and the broadcast nature of wireless transmissions. When a packet is transmitted, overhearing nodes can act as forwarding candidates. The best forwarder is chosen, but if it fails to forward in time, a suboptimal candidate will forward instead to avoid transmission interruptions. Simulation results show EPOR achieves higher packet delivery ratios and lower end-to-end delays than GPSR and AOMDV routing protocols, even under high node mobility.
Consistent Data Release in MANET Using Light Weight Verification Algorithm wi...IJCERT
IJCERT Standard on-line Journal
ISSN(Online):2349-7084,(An ISO 9001:2008 Certified Journal)
iso nicir csir
http://www.ijcert.org offers Discount for Indian research Scholars
IJCERT (ISSN 2349–7084 (Online)) is approved by National Science Library (NSL), National Institute of Science Communication And Information Resources (NISCAIR), Council of Scientific and Industrial Research, New Delhi, India.
DATA FORWARDING IN OPPORTUNISTIC NETWORK USING MOBILE TRACEScscpconf
Opportunistic networks are usually formed spontaneously by mobile devices equipped with
short range wireless communication interfaces. The idea is that an end-to-end connection may
never be present. Designing and implementing a routing protocol to support both service
discovery and delivery in such kinds of networks is a challenging problem on account of
frequent disconnections and topology changes. In these networks one of the most important
issues relies on the selection of the best intermediate node to forward the messages towards the
destination. This paper presents a mobile trace based routing protocol that uses the location
information of the nodes in the network. Using the trace information, next hop is selected to forward the packets to destination. Data forwarding is done via the selected nodes. The effectiveness is shown using simulation
FAULT-TOLERANT MULTIPATH ROUTING SCHEME FOR ENERGY EFFICIENT WIRELESS SENSOR ...ijwmn
Themain challengein wireless sensor network is to improve the fault tolerance of each
node and also provide an energy efficient fast data routing service. In this paper we propose an
energyefficient node fault diagnosis and recovery for wireless sensor networks referred as fault tolerant
multipath routing scheme for energy efficientwireless sensor network (FTMRS).The FTMRSis based on
multipath data routing scheme. One shortest path is use for main data routing in FTMRS technique and
other two backup paths are used as alternative path for faulty network and to handle the overloaded
traffic on main channel.Shortest path data routing ensures energy efficient data routing. The
performance analysis of FTMRSshows better results compared to other popular fault tolerant techniques
in wireless sensor networks.
Improving QoS-based Routing by Limiting Interference in Lossy Wireless Sensor...ijwmn
This document proposes a routing protocol for wireless sensor networks that aims to improve QoS metrics like throughput and delay. It does this by limiting interference during the route discovery phase using an epidemic algorithm. The protocol uses probabilistic interest flooding and exploratory data propagation to reduce unnecessary flooding and make the interference levels during route discovery more similar to actual data transmission. Simulation results show there is an optimal percentage of neighbors to forward messages that achieves the best throughput and delay.
PERFORMANCE ANALYSIS OF OLSR PROTOCOL IN MANET CONSIDERING DIFFERENT MOBILITY...ijwmn
A Mobile Ad Hoc Network (MANET) is created when an independent mobile node network is connected
dynamically via wireless links. MANET is a self-organizing network that does not rely on pre-existing
infrastructure such as wired or wireless network routers. Mobile nodes in this network move randomly,
thus, the topology is always changing. Routing protocols in MANET are critical in ensuring dependable
and consistent connectivity between the mobile nodes. They conclude logically based on the interaction
between mobile nodes in MANET routing and encourage them to choose the optimum path between source
and destination. Routing protocols are classified as proactive, reactive, or hybrid. The focus of this project
will be on Optimized Link State Routing (OLSR) protocol, a proactive routing technique. OLSR is known as
the optimized variant of link state routing in which packets are sent throughout the network using the
multipoint relay (MPR) mechanism. This article evaluates the performance of the OLSR routing protocol
under condition of changing mobility speed and network density. The study's performance indicators are
average packet throughput, packet delivery ratio (PDR), and average packet latency. Network Simulator 2
(NS-2) and an external patch UM-OLSR are used to simulate and evaluate the performance of such
protocol. As a result of research, the approach of implementing the MPR mechanism are able to minimise
redundant data transmission during the normal message broadcast. The MPRs enhance the link state
protocols’ traditional diffusion mechanism by selecting the right MPRs. Hence, the number of undesired
broadcasts can be reduced and limited. Further research will focus on different scenario and environment
using different mobility model
PERFORMANCE ANALYSIS OF CHANNEL ACCESS MODEL FOR MAC IN RANDOMLY DISTRIBUTED ...IJCNCJournal
Medium Access control (MAC) is one of the fundamental problems in wireless sensor networks. The performance of wireless sensor network depends on it. The main objective of a medium access control method is to provide high throughput, minimize the delay, and conservers the energy consumption by avoiding the collisions. In this paper, a general model for MAC protocol to reduce the delay, maximize throughput and conserve the energy consumption in channel accessing in high density randomly distributed wireless sensor network is presented. The proposed model is simulated using MATLAB. The simulation results show that the average delay for sensors with sufficient memory is lower than sensors without
memory. Further, the throughput of the channel access method with memory is better than without memory.
MANET Routing Protocols , a case studyRehan Hattab
L. Yi, Y. Zhai, Y. Wang, J. Yuan and I. You , Impacts of Internal Network Contexts on Performance of MANET Routing Protocols: a Case Study, Sixth International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing,2012.
A New Approach to Improve the Efficiency of Distributed Scheduling in IEEE 80...IDES Editor
The recent standard for broadband wireless
access networks, IEEE 802.16, which resulted in the
development of metropolitan area wireless networks,
includes two network organization modes: Point to Multi
Point and Mesh. The mesh mode provides distributed
channel access operations of peering nodes and uses TDMA
technique for channel access modulation. According to
IEEE 802.16 MAC protocol, there are two scheduling
algorithms for assigning TDMA slots to each network node:
centralized and distributed. In distributed scheduling
algorithm, network nodes have to transmit scheduling
message in order to inform other nodes about their transfer
schedule. In this paper a new approach is proposed to
improve distributed scheduling efficiency in IEEE 802.16
mesh mode, with respect to network condition in every
transferring opportunity. For evaluating the proposed
algorithm efficiency, several extensive simulations are
performed in various network configurations and the most
important system parameters which affect the network
performance are analyzed.
BER Performance of MU-MIMO System using Dirty Paper CodingIJEEE
In this paper Dirty Paper Coding for communication system is implemented. MIMO application that involves devices such as cell phones, pocket PCs require closely spaced antenna, which suffers from mutual coupling among antennas and high spatial correlation for signals. DPC is used for compensating the degradation due to correlation and mutual coupling.
Average Channel Capacity of Amplify-and-forward MIMO/FSO Systems Over Atmosph...IJECEIAES
In amplify-and-forward (AF) relay channel, when the direct link between source and destination terminals is deeply faded, the signal from the source terminal to the destination terminal propagates through the relay terminals, each of which relays a signal received from the previous terminal to the next terminal in series. This paper, we theoretically analyze the performance of multiple-input multiple-output (MIMO) AF free-space optical (FSO) systems. The AF-MIMO/FSO average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) is derived taking into account the atmospheric turbulence effects on the MIMO/FSO channel. They are modeled by log-normal and the gamma-gamma distributions for the cases of weak-to-strong turbulence conditions. We extract closed form mathematical expression for the evaluation of the ACC and we quantitatively discuss the influence of turbulence strength, link distance, different number of relay stations and different MIMO configurations on it.
At this present scenario, the demand of the system capacity is very high in wireless network. MIMO
technology is used from the last decade to provide this requirement for wireless network antenna
technology. MIMO channels are mostly used for advanced antenna array technology. But it is most
important to control the error rate with enhanced system capacity in MIMO for present-day progressive
wireless communication. This paper explores the frame error rate with respect to different path gain of
MIMO channel. This work has been done in different fading scenario and produces a comparative analysis
of MIMO on the basis of those fading models in various conditions. Here, it is to be considered that
modulation technique as QPSK to observe these comparative evaluations for different Doppler frequencies.
From the comparative analysis, minimum amount of frame error rate is viewed for Rician distribution at
LOS path Doppler shift of 0 Hz. At last, this work is concluded with a comparative bit error rate study on
the basis of singular parameters at different SNR levels to produce the system performance for uncoded
QPSK modulation.
Performance Analysis of PAPR Reduction in MIMO-OFDMIJARBEST JOURNAL
Authors: Jayaraman.G1, VeeraKumar K2, Selvakani.S3
Abstract— In communication system, it is aimed to provide highest possible
transmission rate at the lowest possible power and with the least possible noise. MIMOOFDM
has been chosen for high data rate communications and widely deployed in many
wireless communication standards. The major drawback in OFDM signal transmission is
high PAPR. In previous, use clipping technique to tackle this problem. In this paper, use
EM-GAMP algorithm to reduce PAPR in considerable amount.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
MIMO Channel Estimation Using the LS and MMSE AlgorithmIOSRJECE
Wireless Communication Technology has developed over the past few yearsfor other objectives.The Multiple InputMultiple Output (MIMO) is one of techniques that is used to enhancethe data rates, in which multiple antennas are employed both the transmitter and receiver. Multiple signals are transmitted from different antennas at the transmitter using the same frequency and separated space. Various channel estimation techniques are employed in order to judge the physical effects of the medium present. In this paper, we analyze and implementvarious estimation techniques for MIMO Systems such as Least Squares (LS), Minimum Mean Square Error (MMSE),these techniques are therefore compared to effectively estimate the channel in MIMO System. The results demonstrate that SNR required to support different values of bit error rate varies depending on different low correlation between the transmitting and the receiving antennas .In addition, it is illustrated that when the number of transmitter and receiver antennas increases, the performance of TBCE schemes significantly improves. The Same behavior isalso observed for MIMO system. Performance of both MMSE and LSestimation are the same for allkinds of modulation at small value of SNR but the more we increase the SNR value the more performance gap goes on increasing.
Comparison of energy efficient data transmission approaches for flat wireless...ijassn
In this paper we have analyzed energy efficient neighbour selection algorithms for routing in wireless
sensor networks. Since energy saving or consumption is an important aspect of wireless sensor networks,
its precise usage is highly desirable both for the faithful performance of network and to increase the
network life time. For this work, we have considered a flat network topology where every node has the
same responsibility and capability. We have compared two energy efficient algorithms and analyzed their
performances when all sensor nodes in a network have either homogeneous or heterogeneous energy with
increase in number of nodes, time rounds and node failures.
INCREASE THE LIFETIME OF WIRELESS SENSOR NETWORKS USING HIERARCHICAL CLUSTERI...ijwmn
Wireless sensor networks consist of hundreds or thousands of nodes with limited energy. Since the life time
of each sensor is equivalent to the battery life, the energy issue is considered as a major challenge.
Clustering has been proposed as a strategy to extend the lifetime of wireless sensor networks. Cluster size,
number of Cluster head per cluster and the selection of cluster head are considered as important factors in
clustering. In this research by studying LEACH algorithm and optimized algorithms of this protocol and by
evaluating the strengths and weaknesses, a new algorithm based on hierarchical clustering to increase the
lifetime of the sensor network is proposed. In this study, with a special mechanism the environment of
network is layered and the optimal number of cluster head in each layer is selected and then recruit for the
formation of clusters in the same layer by controlling the topology of the clusters is done independently.
Then the data is sent through the by cluster heads through the multi- stage to the main station. Simulation
results show that the above mentioned method increases the life time about 70% compared to the LEACH.
Introducing a novel fault tolerant routing protocol in wireless sensor networ...ijcsit
Although routing is one of the key network issues, the challenges facing WSN makes the subject even more
demanding. In this study, we propose a novel fault tolerant routing protocol in wireless sensor networks
using fuzzy logic. We approach the problem by breaking it down into two parts. The first sub problem is
designing a routing module and the second one retrofitting the designed module in a way that answering to
these two sub problems leads to the final solution of the main problem. To deal with the first stage, by using
fuzzy logic, we design a routing module; then for the second stage, the module enters fault tolerant routing
in order that it be tolerant against routing faults. In this study, the term "network failure" is figuratively
equal to "node failure".
A novel defence scheme against selfish Node attack in manetijcsa
This document proposes a new intrusion detection system (IDS) algorithm to defend against selfish node attacks in mobile ad hoc networks (MANETs). Selfish nodes flood the network with false information and drop packets from other nodes. The proposed IDS identifies selfish node behavior and blocks their activities. Simulation results show the IDS enhances network performance from negligible to 92% and prevents infection from attacks. The IDS is integrated with the AODV routing protocol to detect and eliminate selfish nodes within its transmission range.
Effective Path Identification Protocol for Wireless Mesh NetworksIDES Editor
Wireless Mesh Networks (WMNs) have emerged as
a key technology for next-generation wireless networking.
Routing is a key factor for transfer of packets from source to
destination. SrcRR is widely used protocol for transferring
packets from source to destination. This protocol often uses
Dijkstra’s algorithm on its link state database to find the next
alternative path to the destination when ever the ETX metric
of the link changes.This is a time consuming process if the
ETX metric of the links are changing frequently. So this paper
eliminates the use of Dijkistra’s algorithm and uses the a
search operation for finding the best paths.
A black-hole attack in the Mobile Ad-hoc NETwork (MANET) is an attack occurs due to malicious nodes,
which attracts the data packets by falsely advertising a fresh route to the destination. In this paper, we
present a clustering approach in Ad-hoc On-demand Distance Vector (AODV) routing protocol for the
detection and prevention of black-hole attack in MANETs. In this approach every member of the cluster will
ping once to the cluster head, to detect the peculiar difference between the number of data packets received
and forwarded by the node. If anomalousness is perceived, all the nodes will obscure the malicious nodes
from the network.
A new method for controlling and maintainingIJCNCJournal
Topology Control is an essential technique in a wireless sensor network to extend the operational time of
the sensor nodes. The goal of this technique is to maintain network connectivity and optimize performance
metrics such as network lifetime and throughput. In this paper we presented a new method for controlling
and maintaining topology in wireless sensor networks that show some improvement over the state of art
methods. The results are analyzed based on objective criteria.
The document summarizes an Efficient Position-Based Opportunistic Routing (EPOR) protocol proposed for mobile ad hoc networks. EPOR takes advantage of geographic routing and the broadcast nature of wireless transmissions. When a packet is transmitted, overhearing nodes can act as forwarding candidates. The best forwarder is chosen, but if it fails to forward in time, a suboptimal candidate will forward instead to avoid transmission interruptions. Simulation results show EPOR achieves higher packet delivery ratios and lower end-to-end delays than GPSR and AOMDV routing protocols, even under high node mobility.
Consistent Data Release in MANET Using Light Weight Verification Algorithm wi...IJCERT
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ISSN(Online):2349-7084,(An ISO 9001:2008 Certified Journal)
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http://www.ijcert.org offers Discount for Indian research Scholars
IJCERT (ISSN 2349–7084 (Online)) is approved by National Science Library (NSL), National Institute of Science Communication And Information Resources (NISCAIR), Council of Scientific and Industrial Research, New Delhi, India.
DATA FORWARDING IN OPPORTUNISTIC NETWORK USING MOBILE TRACEScscpconf
Opportunistic networks are usually formed spontaneously by mobile devices equipped with
short range wireless communication interfaces. The idea is that an end-to-end connection may
never be present. Designing and implementing a routing protocol to support both service
discovery and delivery in such kinds of networks is a challenging problem on account of
frequent disconnections and topology changes. In these networks one of the most important
issues relies on the selection of the best intermediate node to forward the messages towards the
destination. This paper presents a mobile trace based routing protocol that uses the location
information of the nodes in the network. Using the trace information, next hop is selected to forward the packets to destination. Data forwarding is done via the selected nodes. The effectiveness is shown using simulation
FAULT-TOLERANT MULTIPATH ROUTING SCHEME FOR ENERGY EFFICIENT WIRELESS SENSOR ...ijwmn
Themain challengein wireless sensor network is to improve the fault tolerance of each
node and also provide an energy efficient fast data routing service. In this paper we propose an
energyefficient node fault diagnosis and recovery for wireless sensor networks referred as fault tolerant
multipath routing scheme for energy efficientwireless sensor network (FTMRS).The FTMRSis based on
multipath data routing scheme. One shortest path is use for main data routing in FTMRS technique and
other two backup paths are used as alternative path for faulty network and to handle the overloaded
traffic on main channel.Shortest path data routing ensures energy efficient data routing. The
performance analysis of FTMRSshows better results compared to other popular fault tolerant techniques
in wireless sensor networks.
Improving QoS-based Routing by Limiting Interference in Lossy Wireless Sensor...ijwmn
This document proposes a routing protocol for wireless sensor networks that aims to improve QoS metrics like throughput and delay. It does this by limiting interference during the route discovery phase using an epidemic algorithm. The protocol uses probabilistic interest flooding and exploratory data propagation to reduce unnecessary flooding and make the interference levels during route discovery more similar to actual data transmission. Simulation results show there is an optimal percentage of neighbors to forward messages that achieves the best throughput and delay.
PERFORMANCE ANALYSIS OF OLSR PROTOCOL IN MANET CONSIDERING DIFFERENT MOBILITY...ijwmn
A Mobile Ad Hoc Network (MANET) is created when an independent mobile node network is connected
dynamically via wireless links. MANET is a self-organizing network that does not rely on pre-existing
infrastructure such as wired or wireless network routers. Mobile nodes in this network move randomly,
thus, the topology is always changing. Routing protocols in MANET are critical in ensuring dependable
and consistent connectivity between the mobile nodes. They conclude logically based on the interaction
between mobile nodes in MANET routing and encourage them to choose the optimum path between source
and destination. Routing protocols are classified as proactive, reactive, or hybrid. The focus of this project
will be on Optimized Link State Routing (OLSR) protocol, a proactive routing technique. OLSR is known as
the optimized variant of link state routing in which packets are sent throughout the network using the
multipoint relay (MPR) mechanism. This article evaluates the performance of the OLSR routing protocol
under condition of changing mobility speed and network density. The study's performance indicators are
average packet throughput, packet delivery ratio (PDR), and average packet latency. Network Simulator 2
(NS-2) and an external patch UM-OLSR are used to simulate and evaluate the performance of such
protocol. As a result of research, the approach of implementing the MPR mechanism are able to minimise
redundant data transmission during the normal message broadcast. The MPRs enhance the link state
protocols’ traditional diffusion mechanism by selecting the right MPRs. Hence, the number of undesired
broadcasts can be reduced and limited. Further research will focus on different scenario and environment
using different mobility model
PERFORMANCE ANALYSIS OF CHANNEL ACCESS MODEL FOR MAC IN RANDOMLY DISTRIBUTED ...IJCNCJournal
Medium Access control (MAC) is one of the fundamental problems in wireless sensor networks. The performance of wireless sensor network depends on it. The main objective of a medium access control method is to provide high throughput, minimize the delay, and conservers the energy consumption by avoiding the collisions. In this paper, a general model for MAC protocol to reduce the delay, maximize throughput and conserve the energy consumption in channel accessing in high density randomly distributed wireless sensor network is presented. The proposed model is simulated using MATLAB. The simulation results show that the average delay for sensors with sufficient memory is lower than sensors without
memory. Further, the throughput of the channel access method with memory is better than without memory.
MANET Routing Protocols , a case studyRehan Hattab
L. Yi, Y. Zhai, Y. Wang, J. Yuan and I. You , Impacts of Internal Network Contexts on Performance of MANET Routing Protocols: a Case Study, Sixth International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing,2012.
A New Approach to Improve the Efficiency of Distributed Scheduling in IEEE 80...IDES Editor
The recent standard for broadband wireless
access networks, IEEE 802.16, which resulted in the
development of metropolitan area wireless networks,
includes two network organization modes: Point to Multi
Point and Mesh. The mesh mode provides distributed
channel access operations of peering nodes and uses TDMA
technique for channel access modulation. According to
IEEE 802.16 MAC protocol, there are two scheduling
algorithms for assigning TDMA slots to each network node:
centralized and distributed. In distributed scheduling
algorithm, network nodes have to transmit scheduling
message in order to inform other nodes about their transfer
schedule. In this paper a new approach is proposed to
improve distributed scheduling efficiency in IEEE 802.16
mesh mode, with respect to network condition in every
transferring opportunity. For evaluating the proposed
algorithm efficiency, several extensive simulations are
performed in various network configurations and the most
important system parameters which affect the network
performance are analyzed.
BER Performance of MU-MIMO System using Dirty Paper CodingIJEEE
In this paper Dirty Paper Coding for communication system is implemented. MIMO application that involves devices such as cell phones, pocket PCs require closely spaced antenna, which suffers from mutual coupling among antennas and high spatial correlation for signals. DPC is used for compensating the degradation due to correlation and mutual coupling.
Average Channel Capacity of Amplify-and-forward MIMO/FSO Systems Over Atmosph...IJECEIAES
In amplify-and-forward (AF) relay channel, when the direct link between source and destination terminals is deeply faded, the signal from the source terminal to the destination terminal propagates through the relay terminals, each of which relays a signal received from the previous terminal to the next terminal in series. This paper, we theoretically analyze the performance of multiple-input multiple-output (MIMO) AF free-space optical (FSO) systems. The AF-MIMO/FSO average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) is derived taking into account the atmospheric turbulence effects on the MIMO/FSO channel. They are modeled by log-normal and the gamma-gamma distributions for the cases of weak-to-strong turbulence conditions. We extract closed form mathematical expression for the evaluation of the ACC and we quantitatively discuss the influence of turbulence strength, link distance, different number of relay stations and different MIMO configurations on it.
At this present scenario, the demand of the system capacity is very high in wireless network. MIMO
technology is used from the last decade to provide this requirement for wireless network antenna
technology. MIMO channels are mostly used for advanced antenna array technology. But it is most
important to control the error rate with enhanced system capacity in MIMO for present-day progressive
wireless communication. This paper explores the frame error rate with respect to different path gain of
MIMO channel. This work has been done in different fading scenario and produces a comparative analysis
of MIMO on the basis of those fading models in various conditions. Here, it is to be considered that
modulation technique as QPSK to observe these comparative evaluations for different Doppler frequencies.
From the comparative analysis, minimum amount of frame error rate is viewed for Rician distribution at
LOS path Doppler shift of 0 Hz. At last, this work is concluded with a comparative bit error rate study on
the basis of singular parameters at different SNR levels to produce the system performance for uncoded
QPSK modulation.
Performance Analysis of PAPR Reduction in MIMO-OFDMIJARBEST JOURNAL
Authors: Jayaraman.G1, VeeraKumar K2, Selvakani.S3
Abstract— In communication system, it is aimed to provide highest possible
transmission rate at the lowest possible power and with the least possible noise. MIMOOFDM
has been chosen for high data rate communications and widely deployed in many
wireless communication standards. The major drawback in OFDM signal transmission is
high PAPR. In previous, use clipping technique to tackle this problem. In this paper, use
EM-GAMP algorithm to reduce PAPR in considerable amount.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
MIMO Channel Estimation Using the LS and MMSE AlgorithmIOSRJECE
Wireless Communication Technology has developed over the past few yearsfor other objectives.The Multiple InputMultiple Output (MIMO) is one of techniques that is used to enhancethe data rates, in which multiple antennas are employed both the transmitter and receiver. Multiple signals are transmitted from different antennas at the transmitter using the same frequency and separated space. Various channel estimation techniques are employed in order to judge the physical effects of the medium present. In this paper, we analyze and implementvarious estimation techniques for MIMO Systems such as Least Squares (LS), Minimum Mean Square Error (MMSE),these techniques are therefore compared to effectively estimate the channel in MIMO System. The results demonstrate that SNR required to support different values of bit error rate varies depending on different low correlation between the transmitting and the receiving antennas .In addition, it is illustrated that when the number of transmitter and receiver antennas increases, the performance of TBCE schemes significantly improves. The Same behavior isalso observed for MIMO system. Performance of both MMSE and LSestimation are the same for allkinds of modulation at small value of SNR but the more we increase the SNR value the more performance gap goes on increasing.
Study on transmission over Nakagami-m fading channel for multiple access sche...TELKOMNIKA JOURNAL
In this paper, a downlink performance in non-orthogonal multiple access (NOMA) system is considered. With regard to different priority for two NOMA users, we exploit the closed-form expressions of outage probability over wireless fading channel following Nakagami-m fading. The fixed power allocation factor scheme is examined to reduce the complexity in computation regarding performance analysis. In our analysis, perfect successive interference cancellation (SIC) is applied in order to achieve perfect signal decoding operation. Simulation results show that the considered NOMA downlink scheme is affected by transmit SNR, power allocation factors, fading parameters.
Performance of the MIMO-MC-CDMA System with MMSE EqualizationTamilarasan N
Multipath fading and spectral crowding are the
major challenges in dealing higher data rate in future
broadband wireless communication system. Multi-carrier
Modulation like Multicarrier code division multiple access
(MC-CDMA) can tackle the problem and provide higher data
rate for future wireless communication system. However,
through a frequency selective fading channel, the subcarriers
in MC-CDMA signal have different amplitude levels and phase
shifts which result in loss of the orthogonality among users
and generates Multiple access interference (MAI). To combat
the MAI, various amplitude and phase equalizing techniques
such as Maximum Ratio Combining (MRC), Equal Gain
Combining (EGC), Orthogonal Restoring Combining (ORC),
Threshold Orthogonal Restoring Combining or Minimum
Mean Square Error (MMSE) may be used. Out of these MMSE
offers better performance since the MMSE criterion is applied
independently on each subcarrier. Further improvement in
performance is possible through space–time block coding,
which offers maximum diversity gain and multiplexing gain.
This paper combines MC-CDMA with MMSE equalization
and space–time block coding which proves to be a powerful
physical layer solution in combating delay spread and inter
symbol interference (ISI).
Effect on Channel Capacity of Multi-User MIMO System in Crowded AreaIJEEE
1) The document analyzes the effect of multi-user MIMO (MU-MIMO) systems on channel capacity in crowded urban areas compared to single-user MIMO (SU-MIMO) systems.
2) It finds that MU-MIMO can achieve higher channel capacity than SU-MIMO in urban environments due to lower spatial correlation between users, unlike assumptions of independent channels in MIMO transmission.
3) The improvement of MU-MIMO capacity over SU-MIMO increases with path visibility, with MU-MIMO showing better performance when path visibility is over 13%.
Joint impacts of relaying scheme and wireless power transfer in multiple acce...journalBEEI
This paper considers ergodic capacity of energy harvesting (EH) based cellular networks. Such a network employs non-orthogonal multiple access (NOMA) together with relaying scheme to serve two far users. In this system model, relay is facilitated power splitting (PS) protocol to implement energy harvesting (EH). To examine capacity, expressions of signal to noise ratio (SNR) need be computed to achieve capacity. Power allocation factors are different for two users in such system and hence performance gap happens to distinguish requirements for separated users. It can be confirmed that the proposed paradigm exhibits maximal achievable capacity in some scenarios of setting parameters. To confirm exactness of the analytical expressions and show advantages of the proposed EH-NOMA, simulation results are performed in terms of ergodic capacity.
Bit Error Rate Performance of MIMO Spatial Multiplexing with MPSK Modulation ...ijsrd.com
Wireless communication is one of the most effective areas of technology development of our time. Wireless communications today covers a very wide array of applications. In this, we study the performance of general MIMO system, the general V-BLAST architecture with MPSK Modulation in Rayleigh fading channels. Based on bit error rate, we show the performance of the 2x2 schemes with MPSK Modulation in noisy environment. We also show the bit error rate performance of 2x2, 3x3, 4x4 systems with BPSK modulation. We see that the bit error rate performance of 2x2 systems with QPSK modulation gives us the best performance among other schemes analysed here.
ANALYTICAL PERFORMANCE EVALUATION OF A MIMO FSO COMMUNICATION SYSTEM WITH DIR...optljjournal
MIMO FSO correspondence is examined as of late to build up a hearty correspondence connects within the sight of atmospheric turbulence. In this paper an analytical approach is developed to assess the impact of atmospheric turbulence on BER performance of a MIMO FSO communication system with Q-ary Pulse Position Modulation (QPPM). Examination is exhibited to discover flag to clamor proportion at the yield of an immediate location collector with optical power modulator under strong turbulent condition which is modeled as gamma-gamma distribution. The outcomes demonstrate that the BER performance is emphatically debased because of the impact of atmospheric turbulence. In any case, the execution can be enhanced by expanding the quantity of transmitters, beneficiaries and request of Q in PPM. Results demonstrate that the FSO MIMO framework with M=8, N=4 Q=4 gives the 22 dB improvement at BER of 10-9 .
ANALYTICAL PERFORMANCE EVALUATION OF A MIMO FSO COMMUNICATION SYSTEM WITH DIR...optljjournal
MIMO FSO correspondence is examined as of late to build up a hearty correspondence connects within the
sight of atmospheric turbulence. In this paper an analytical approach is developed to assess the impact of
atmospheric turbulence on BER performance of a MIMO FSO communication system with Q-ary Pulse
Position Modulation (QPPM). Examination is exhibited to discover flag to clamor proportion at the yield
of an immediate location collector with optical power modulator under strong turbulent condition which is
modeled as gamma-gamma distribution. The outcomes demonstrate that the BER performance is
emphatically debased because of the impact of atmospheric turbulence
In this paper, we analyzed a numerical evaluation of the performance of MIMO radio systems in the LTE network environment. Downlink physical layer of the OFDM-MIMO based radio interface is considered for system model and a theoretical analysis of the bit error rate of the two space-time codes (SFBC 2×1 and FSTD 4×2 codes are adopted by the LTE norm as a function of the signal to noise ratio. Analytical expressions are given for transmission over a Rayleigh channel without spatial correlation which is then compared with Monte-Carlo simulations. Further evaluated channel capacity and simulation results show throughput almost reaches to the capacity limit.
Intersymbol interference caused by multipath in band limited frequency selective time dispersive channels distorts the transmitted signal, causing bit error at receiver. ISI is the major obstacle to high speed data transmission over wireless channels. Channel estimation is a technique used to combat the intersymbol interference. The objective of this paper is to improve channel estimation accuracy in MIMO-OFDM system by using modified variable step size leaky Least Mean Square (MVSSLLMS) algorithm proposed for MIMO OFDM System. So we are going to analyze Bit Error Rate for different signal to noise ratio, also compare the proposed scheme with standard LMS channel estimation method.
Tractable computation in outage performance analysis of relay selection NOMATELKOMNIKA JOURNAL
In recent years, using full-duplex (FD) transmission model provides enhanced bandwidth efficiency and improved performance for non-orthogonal multiple access (NOMA) system. However, lack of papers have investigated FD relay together with relay selection issue to improve performance of NOMA system. The problems in power allocation for two NOMA users satisfying fairness as well as relay selection strategy are studied in this paper. By considering the outage performance of proposed scheme with its vital result, general NOMA wireless networks can be developed for future networks due to its improved performance. Simulation results show that the relaying selection scheme can achieve a significant performance improvement by increasing required quantity of relay.
Index modulation is one of the promising techniques for future communications systems due to many improvement over the classical orthogonal frequency division multiplexing systems such as single RF chain, increased throughput for the same modulation order, achieved tradeoff between the efficiencies of the power and the spectral, and elimination of inter-channel interference. Many forms of index modulation researches exist where symbols are conveyed in antennas, subcarriers, time slots, and the space-time matrix. Spatial modulation is one member of index modulation family where symbols are conveyed in activating transmit/receive antennas. In this paper, a modification to a standard multiple input single output scheme by integrating spatial modulation using simplified mathematical procedure is achieved. In the transmitter side, data and activation symbols are distributed simultaneously using mathematical module and floor functions. At the receiver, a simplified maximum likelihood detector is used to obtain transmitted pair of symbols. To verify this, MATLAB simulink is used to simulate a downlink system where spatial modulation is applied to a base station. Results for different transmit antenna number and modulation order are obtained in the form of bit error rate versus signal to noise ratio.
This document summarizes a study that used two methods - nonlinear autoregressive neural network prediction (NARNN) and one-dimensional multilevel wavelet de-noising technique (1D MDT) - to predict path loss of GSM signals in an urban environment in Dnepropetrovsk, Ukraine. The NARNN had a mean square error of 3.3978dB while the 1D MDT had 3.428dB, showing the NARNN performed slightly better at 3.02%. Both methods predicted signal attenuation in the study area. Neural network clustering also revealed signal strengths between -75dB to -95dB were most common, indicating mostly weak signals were received.
IMPACT OF FADING CORRELATION, POLARIZATION COUPLING AND KEYHOLES ON MIMO DETE...ijmnct
This document summarizes a research paper that analyzes the impact of fading correlation, cross polarization coupling, and the keyhole effect on the error performance of V-BLAST MIMO systems using detectors like ZF, MMSE, and ML. It is observed that performance is better when channel fading correlation and cross polarization coupling values are lower. The keyhole effect can cause the channel matrix to be rank deficient, limiting the benefits of multiple antennas. Simulation results show the BER performance of these detectors for different modulation schemes under varying channel conditions.
This document summarizes a new complexity reduction method for V-BLAST MIMO systems in communication channels. It proposes two methods: 1) a low complexity QR algorithm and 2) a consecutive iterations reduction method. These methods are compared to traditional detection methods like zero forcing (ZF), minimum mean square error (MMSE), successive interference cancellation (SIC), and maximum likelihood (ML). Simulation results show that the proposed algorithms not only reduce computational complexity but also achieve significantly better bit error rate and probability of error performance compared to traditional V-BLAST techniques. The document analyzes the performance of different equalizers using the V-BLAST algorithm and evaluates the proposed methods versus traditional approaches.
Similar to BER ANALYSIS FOR DOWNLINK MIMO-NOMA SYSTEMS OVER RAYLEIGH FADING CHANNELS (20)
Rendezvous Sequence Generation Algorithm for Cognitive Radio Networks in Post...IJCNCJournal
Recent natural disasters have inflicted tremendous damage on humanity, with their scale progressively increasing and leading to numerous casualties. Events such as earthquakes can trigger secondary disasters, such as tsunamis, further complicating the situation by destroying communication infrastructures. This destruction impedes the dissemination of information about secondary disasters and complicates post-disaster rescue efforts. Consequently, there is an urgent demand for technologies capable of substituting for these destroyed communication infrastructures. This paper proposes a technique for generating rendezvous sequences to swiftly reconnect communication infrastructures in post-disaster scenarios. We compare the time required for rendezvous using the proposed technique against existing methods and analyze the average time taken to establish links with the rendezvous technique, discussing its significance. This research presents a novel approach enabling rapid recovery of destroyed communication infrastructures in disaster environments through Cognitive Radio Network (CRN) technology, showcasing the potential to significantly improve disaster response and recovery efforts. The proposed method reduces the time for the rendezvous compared to existing methods, suggesting that it can enhance the efficiency of rescue operations in post-disaster scenarios and contribute to life-saving efforts.
Blockchain Enforced Attribute based Access Control with ZKP for Healthcare Se...IJCNCJournal
The relationship between doctors and patients is reinforced through the expanded communication channels provided by remote healthcare services, resulting in heightened patient satisfaction and loyalty. Nonetheless, the growth of these services is hampered by security and privacy challenges they confront. Additionally, patient electronic health records (EHR) information is dispersed across multiple hospitals in different formats, undermining data sovereignty. It allows any service to assert authority over their EHR, effectively controlling its usage. This paper proposes a blockchain enforced attribute-based access control in healthcare service. To enhance the privacy and data-sovereignty, the proposed system employs attribute-based access control, zero-knowledge proof (ZKP) and blockchain. The role of data within our system is pivotal in defining attributes. These attributes, in turn, form the fundamental basis for access control criteria. Blockchain is used to keep hospital information in public chain but EHR related data in private chain. Furthermore, EHR provides access control by using the attributed based cryptosystem before they are stored in the blockchain. Analysis shows that the proposed system provides data sovereignty with privacy provision based on the attributed based access control.
EECRPSID: Energy-Efficient Cluster-Based Routing Protocol with a Secure Intru...IJCNCJournal
A revolutionary idea that has gained significance in technology for Internet of Things (IoT) networks backed by WSNs is the " Energy-Efficient Cluster-Based Routing Protocol with a Secure Intrusion Detection" (EECRPSID). A WSN-powered IoT infrastructure's hardware foundation is hardware with autonomous sensing capabilities. The significant features of the proposed technology are intelligent environment sensing, independent data collection, and information transfer to connected devices. However, hardware flaws and issues with energy consumption may be to blame for device failures in WSN-assisted IoT networks. This can potentially obstruct the transfer of data. A reliable route significantly reduces data retransmissions, which reduces traffic and conserves energy. The sensor hardware is often widely dispersed by IoT networks that enable WSNs. Data duplication could occur if numerous sensor devices are used to monitor a location. Finding a solution to this issue by using clustering. Clustering lessens network traffic while retaining path dependability compared to the multipath technique. To relieve duplicate data in EECRPSID, we applied the clustering technique. The multipath strategy might make the provided protocol more dependable. Using the EECRPSID algorithm, will reduce the overall energy consumption, minimize the End-to-end delay to 0.14s, achieve a 99.8% Packet Delivery Ratio, and the network's lifespan will be increased. The NS2 simulator is used to run the whole set of simulations. The EECRPSID method has been implemented in NS2, and simulated results indicate that comparing the other three technologies improves the performance measures.
Analysis and Evolution of SHA-1 Algorithm - Analytical TechniqueIJCNCJournal
A 160-bit (20-byte) hash value, sometimes called a message digest, is generated using the SHA-1 (Secure Hash Algorithm 1) hash function in cryptography. This value is commonly represented as 40 hexadecimal digits. It is a Federal Information Processing Standard in the United States and was developed by the National Security Agency. Although it has been cryptographically cracked, the technique is still in widespread usage. In this work, we conduct a detailed and practical analysis of the SHA-1 algorithm's theoretical elements and show how they have been implemented through the use of several different hash configurations.
Optimizing CNN-BiGRU Performance: Mish Activation and Comparative AnalysisIJCNCJournal
Deep learning is currently extensively employed across a range of research domains. The continuous advancements in deep learning techniques contribute to solving intricate challenges. Activation functions (AF) are fundamental components within neural networks, enabling them to capture complex patterns and relationships in the data. By introducing non-linearities, AF empowers neural networks to model and adapt to the diverse and nuanced nature of real-world data, enhancing their ability to make accurate predictions across various tasks. In the context of intrusion detection, the Mish, a recent AF, was implemented in the CNN-BiGRU model, using three datasets: ASNM-TUN, ASNM-CDX, and HOGZILLA. The comparison with Rectified Linear Unit (ReLU), a widely used AF, revealed that Mish outperforms ReLU, showcasing superior performance across the evaluated datasets. This study illuminates the effectiveness of AF in elevating the performance of intrusion detection systems.
An Hybrid Framework OTFS-OFDM Based on Mobile Speed EstimationIJCNCJournal
The Future wireless communication systems face the challenging task of simultaneously providing high-quality service (QoS) and broadband data transmission, while also minimizing power consumption, latency, and system complexity. Although Orthogonal Frequency Division Multiplexing (OFDM) has been widely adopted in 4G and 5G systems, it struggles to cope with a significant delay and Doppler spread in high mobility scenarios. To address these challenges, a novel waveform named Orthogonal Time Frequency Space (OTFS). Designers aim to outperform OFDM by closely aligning signals with the channel behaviour. In this paper, we propose a switching strategy that empowers operators to select the most appropriate waveform based on an estimated speed of the mobile user. This strategy enables the base station to dynamically choose the waveform that best suits the mobile user’s speed. Additionally, we suggest retaining an Integrated Sensing and Communication (ISAC) radar approach for accurate Doppler estimation. This provides precise information to facilitate the waveform selection procedure. By leveraging the switching strategy and harnessing the Doppler estimation capabilities of an ISAC radar.Our proposed approach aims to enhance the performance of wireless communication systems in high mobility cases. Considering the complexity of waveform processing, we introduce an optimized hybrid system that combines OTFS and OFDM, resulting in reduced complexity while still retaining performance benefits.This hybrid system presents a promising solution for improving the performance of wireless communication systems in higher mobility.The simulation results validate the effectiveness of our approach, demonstrating its potential advantages for future wireless communication systems. The effectiveness of the proposed approach is validated by simulation results as it will be illustrated.
Enhanced Traffic Congestion Management with Fog Computing - A Simulation-Base...IJCNCJournal
Accurate latency computation is essential for the Internet of Things (IoT) since the connected devices generate a vast amount of data that is processed on cloud infrastructure. However, the cloud is not an optimal solution. To overcome this issue, fog computing is used to enable processing at the edge while still allowing communication with the cloud. Many applications rely on fog computing, including traffic management. In this paper, an Intelligent Traffic Congestion Mitigation System (ITCMS) is proposed to address traffic congestion in heavily populated smart cities. The proposed system is implemented using fog computing and tested in a crowdedCairo city. The results obtained indicate that the execution time of the simulation is 4,538 seconds, and the delay in the application loop is 49.67 seconds. The paper addresses various issues, including CPU usage, heap memory usage, throughput, and the total average delay, which are essential for evaluating the performance of the ITCMS. Our system model is also compared with other models to assess its performance. A comparison is made using two parameters, namely throughput and the total average delay, between the ITCMS, IOV (Internet of Vehicle), and STL (Seasonal-Trend Decomposition Procedure based on LOESS). Consequently, the results confirm that the proposed system outperforms the others in terms of higher accuracy, lower latency, and improved traffic efficiency.
Rendezvous Sequence Generation Algorithm for Cognitive Radio Networks in Post...IJCNCJournal
Recent natural disasters have inflicted tremendous damage on humanity, with their scale progressively increasing and leading to numerous casualties. Events such as earthquakes can trigger secondary disasters, such as tsunamis, further complicating the situation by destroying communication infrastructures. This destruction impedes the dissemination of information about secondary disasters and complicates post-disaster rescue efforts. Consequently, there is an urgent demand for technologies capable of substituting for these destroyed communication infrastructures. This paper proposes a technique for generating rendezvous sequences to swiftly reconnect communication infrastructures in post-disaster scenarios. We compare the time required for rendezvous using the proposed technique against existing methods and analyze the average time taken to establish links with the rendezvous technique, discussing its significance. This research presents a novel approach enabling rapid recovery of destroyed communication infrastructures in disaster environments through Cognitive Radio Network (CRN) technology, showcasing the potential to significantly improve disaster response and recovery efforts. The proposed method reduces the time for the rendezvous compared to existing methods, suggesting that it can enhance the efficiency of rescue operations in post-disaster scenarios and contribute to life-saving efforts.
Vehicle Ad Hoc Networks (VANETs) have become a viable technology to improve traffic flow and safety on the roads. Due to its effectiveness and scalability, the Wingsuit Search-based Optimised Link State Routing Protocol (WS-OLSR) is frequently used for data distribution in VANETs. However, the selection of MultiPoint Relays (MPRs) plays a pivotal role in WS-OLSR's performance. This paper presents an improved MPR selection algorithm tailored to WS-OLSR, designed to enhance the overall routing efficiency and reduce overhead. The analysis found that the current OLSR protocol has problems such as redundancy of HELLO and TC message packets or failure to update routing information in time, so a WS-OLSR routing protocol based on improved-MPR selection algorithm was proposed. Firstly, factors such as node mobility and link changes are comprehensively considered to reflect network topology changes, and the broadcast cycle of node HELLO messages is controlled through topology changes. Secondly, a new MPR selection algorithm is proposed, considering link stability issues and nodes. Finally, evaluate its effectiveness in terms of packet delivery ratio, end-to-end delay, and control message overhead. Simulation results demonstrate the superior performance of our improved MR selection algorithm when compared to traditional approaches.
May 2024, Volume 16, Number 3 - The International Journal of Computer Network...IJCNCJournal
The International Journal of Computer Networks & Communications (IJCNC) is a bi monthly open access peer-reviewed journal that publishes articles which contribute new results in all areas of Computer Networks & Communications. The journal focuses on all technical and practical aspects of Computer Networks & data Communications. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on advanced networking concepts and establishing new collaborations in these areas.
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BER ANALYSIS FOR DOWNLINK MIMO-NOMA SYSTEMS OVER RAYLEIGH FADING CHANNELS
1. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
DOI: 10.5121/ijcnc.2021.13606 93
BER ANALYSIS FOR DOWNLINK MIMO-NOMA
SYSTEMS OVER RAYLEIGH FADING CHANNELS
Vu Tran Hoang Son1, 2
and Dang Le Khoa1,2*
1
VNUHCM - University of Science, Ho Chi Minh City, Vietnam
2
Vietnam National University, Ho Chi Minh City, Vietnam
ABSTRACT
The Multiple-input multiple-output (MIMO) technique combined with non-orthogonal multiple access
(NOMA) has been considered to enhance total system performance. This paper studies the bit error rate of
two-user power-domain NOMA systems using successive interference cancellation receivers, with zero-
forcing equalization over quasi-static Rayleigh fading channels. Successive interference cancellation
technique at NOMA receivers has been the popular research topic due to its simple implementation,
despite its vulnerability to error propagation. Closed-form expressions are derived for downlink NOMA in
single-input single-output and uncorrelated quasi-static MIMO Rayleigh fading channel. Analytical results
are consolidated with Monte Carlo simulation.
KEYWORDS
Bit error rate, Multiple-input multiple-output, non-orthogonal multiple access.
1. INTRODUCTION
Recent communication systems aim to meet the high capacity requirements. Non-orthogonal
multiple access (NOMA) is not only available in conventional 4G, recommended in 5G and
future 6G due to many outstanding benefits [1, 2]. NOMA can be divided into two main
categories as power-domain NOMA and code-domain NOMA. Successive interference
cancellation (SIC) is well-known in power-domain NOMA systems for its simple
implementation, although it has low performance compared to other detection techniques such as
using log-likelihood ratios[3], or machine learning[4, 5]. There have been many studies in the
probability of outage[6], power allocation[7], system capacity [8], bit error rate (BER)[9-13],
showing that NOMA is superior to conventional orthogonal multiple access[14]. NOMA can be
integrated with multiple input, multiple output(MIMO), which can result in a notable increase in
capacity[15], or even combined with deep neural network and beam forming [16]. To the best of
the authors' knowledge, there is no approach to BER expressions when changing between
multiuser superposition transmission (MUST) categories in 3GPP LTE Release 13 [17, 18] to
generate NOMA signals. The main contributions of this paper are:
1) Closed-form BER expressions for NOMA in two-user scenario with quadrature phase
shift keying(QPSK) modulation over quasi-static single-input single-output (SISO)
Rayleigh fading channels are investigated.
2) Under certain conditions, BER expressions perfectly suit the MIMO case. This is verified
via Monte Carlo simulation.
3) When Rayleigh channel has multiple taps, simulations barely fit analytical results due to
the limited response of zero-forcing(ZF) equalization. Because of this, via simulations,
authors have combined the conventional systems with orthogonal frequency division
2. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
94
multiplexing (OFDM) to reduce inter-symbol interference (ISI), regardless of non-
linearities.
From this section, the paper is organized as follows. Section 2 presents and compares with related
work in the same field. Section 3 introduces the system model and the corresponding parameters.
Based on preexisting papers, Section 4 analyzes BER in MUST category 1. Section 5 proceeded
to MUST category 2 with a different approach, giving unified results when applying in MUST
category 1. Section 6 considered the effect of MIMO in NOMA systems, under certain
constraints, compared to SISO. All expressions are verified in Section 7 via simulations, and
conclusions along with future works are drawn in Section 8.
2. RELATED WORK
BER is one of the key factors to evaluate MIMO-NOMA system performance. This section will
consider related work that analyzes BER in the NOMA system. In [9], BER expressions of uplink
NOMA with SIC receivers has been derived over Additive White Gaussian Noise(AWGN)
channels. In [10], F. Kara has developed BER expressions for downlink NOMA over Rayleigh
fading channels with two users: far user (FU) using binary phase shift keying (BPSK), and near
user (NU) using QPSK. All expressions are followed by simulations. With significant effort, T.
Assaf et al. have introduced analytical BER through Nakagami-m fading channels in scenarios of
two and three users with QPSK modulation in [11], and through AWGN channels with general
M-QAM modulation[13].The authors in [12] investigated BER in QPSK-modulated NOMA
users on the AWGN channel and verified by software defined radio platforms. Similar research in
recent papers shows that NOMA signals are generated using only MUST type 1 and are limited
in SISO systems. Moreover, in the following years, applications of MIMO, or even massive
MIMO (m-MIMO), will be in new generation mobile networks. Our research is to find out the
BER analysis approach united in both MUST type 1 and type 2 in SISO systems, propose a
comparison with MIMO in Rayleigh fading channels, using Monte Carlo simulations to validate
the results.
3. SYSTEM MODEL
3.1. Downlink NOMAsystem
Consider downlink SISO-NOMA system with two user’s equipment (UEs) and a base station
(BS) as depicted in Figure 1.
Figure 1. Downlink SISO-NOMA system
3. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
95
BS will generate NOMA signals using MUST cat.1 or MUST cat.2 [17, 18]. Based on Figure 1,
the generated signal sc
x can be expressed as
1 1 2 2
sc
x P x P x
, (3.1)
where k
x and k
P are respectively kth user’s signals and power allocation coefficients using
QPSK modulation, with BS transmitted power S
P and power allocation ratio satisfies
1 2
S
P P P
, 1 S
P P
,
2 1 S
P P
. For users’ fairness, near user (NU) UE1 will be allocated
less power than far user (FU) UE2, which means 1 2
P P
or 0 0.5
.
For quasi-static fading channel, the received signal at user kth can be described as[19, 20]
k k sc k
y = h x +n , (3.2)
where k
y is the received signal matrix, k
h is the uncorrelated quasi-static Rayleigh channel
matrix with
0,
k k
g
h CN , k
g is the average channel gain
2
E
k k
g
h , k
n is circularly
symmetric white Gaussian noise with
0
0,
k N
n CN , " "
is the convolution operator which can
be reduced to inner product when the channel is single-tap,
E . is the expected value,
2
. is the
Euclidean norm.
SIC process will be conducted at NU. NU will estimate FU’s symbols and use SIC to eliminate
interference by subtracting FU’s symbols from the received signal, then NU decodes its own
symbols. On the other hand, FU does not need to apply SIC, instead detect its symbols by
considering others as noise.
3.2. MIMO-NOMA system
One of the techniques in MIMO is spatial division multiplexing (SDM), which takes advantage of
the multipath channel to enhance system capacity without increasing the bandwidth. Figure 2
presents a downlink MIMO-NOMA system using SDM 2x2.
Figure 2. Downlink MIMO-NOMA system
4. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
96
Because the UEs are identical, we will investigate a general MIMO SDM 2x2 case as Figure 3.
Figure 3. MIMO SDM 2x2 system
If the spacing between the transmitting and receiving antennas is large enough, the scattering
characteristics will be uncorrelated, so each path is independent. Under these conditions, the
desired signal from the target transmitting antenna can be detected by treating other transmitted
signals as interferences. This is called linear signal detection. We will concentrate on the
technique that nullifies the interference, zero-forcing method. From Figure 3, the received signal
matrix can be expressed as [21]
1 1 2 2
m m
= m + z = +
y h h h + z , (3.3)
whereh denotes an uncorrelated MIMO 2x2 Rayleigh channel matrix with
, th
j i entry ji
h for
the single-tap channel gain between the th
i transmit antenna and the th
j receive antenna,
1,2
j and 1,2
i , then 21
12 2
11
2
h h
h h
h .The spatially multiplexed data and the corresponding
received signals in a symbol time are represented by
1 2
,
T
m m
m and
1 2
,
T
y y
y ,
respectively, where i
m is the message from the th
i transmit antenna, j
y is the received signal at
the th
j receive antenna,
.
T
is the matrix transpose operation. The transmission power of each
antenna is assumed to be one. Let
1 2
,
T
z z
z with j
z denote the circularly symmetric white
Gaussian noise with a variance of 2
z
at the th
j receive antenna, and i
h denote the th
i column
vector of the channel matrix h .
The effect of the channel is inverted by a weight matrix w that
1 2
,
T
m m
m wy , therefore,
we can detect the desired signals from each antenna. The ZF technique nullifies the interference
by the weight matrix
1
H H
ZF
w h h h with
.
H
is the Hermitian transpose operation. All
formulas here can be used in the time domain and inner product because of single-tap channel
assumptions, but when the channel is multiple-tap, all quantities need to be in the frequency
domain via the Fourier transform. Received signals after ZF equalization is
1
.
ZF
H H
ZF
m z
m w y
h h h
z
m
(3.4)
5. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
97
As seen in (3.4), each original data stream is separated from the multiplexed signal. After
equalization, every UE (except the strongest one) detects its information using SIC process.
Notice that if the channel has only one tap, a complex h can be presented in the form of
amplitude and phase, such for SISO case that
exp
R I
h h jh h j
h with 2
1
j ,
2 2
R I
h h h
is the magnitude of h , is the argument of h ,then ZF can be implemented
by[10, 21]
2
2
exp
exp .
y y
conj h
h h
y
h j
h
n
x j
h
(3.5)
From (3.5), n and
exp
n j
is different by a phase shift, however, n is circularly symmetric
so n and
exp
n j
have the same probability distribution. This is one of the key factors to
form the composite reference constellation discussed later in Section 4 and Section 0.
4. BER IN MUST CATEGORY 1
Based on (3.5), Figure 4shows the reference constellation to detect signals at each UE when using
MUST category 1. Red bits denote FU’s bits, and black bits are NU’s bits. The order of bits is
ascending, where the most significant bit is leftmost and is stated as the first bit.
Figure 4. Reference constellation at the receiver when using MUST cat.1
6. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
98
4.1. BER of Far User
As seen in Figure 4, the first bit of UE2, which relies only on the in-phase component, will be
detected erroneously when one of these following cases occurs.
2 1
2 0
2 2
I
P P
n h
(4.1)
2 1
2 0
2 2
I
P P
n h
. (4.2)
Considering the second bit of UE2, which depends only on the quadrature component of the
signal, we see that the error cases are identical to (4.1) and (4.2). Assume the prior probability of
0’s and 1’s bit is equal, so the prior probability of each symbol is also equal. The symmetry
between in-phase and quadrature components of the symbol allows us to investigate only one of
them. Therefore, the variance of considered AWGN now is only half of the total noise, e.g.,
0
0,
2
I
N
n
N . By considering maximum likelihood detection rule, scaling
.
Q function, the
error probability of the FU symbols is
2 1 2 1
2 2
2
0 0
2 2 2 2
1 1
2 2
2 2
P P P P
h h
P e Q Q
N N
. (4.3)
Define some notations as
2 2
2 1 2
0
A
P P h
N
2 2
2 1 2
0
E
A
P P h
N
(4.4)
2 2
2 1 2
0
B
P P h
N
2 2
2 1 2
0
E
B
P P h
N
.
In the case of quasi-static Rayleigh channel, using [10, 20, 22] with (4.4), the average BER
expression of UE2 is defined as
2
1
1 1
4 2 2
A B
A B
P e
. (4.5)
4.2. BER of Near User
Based on [10-13], this section proposes an approach to derive BER of NU. Due to the SIC
process, NU detection must be considered under the condition of FU detection. On the other
hand, in Figure 4, if the second bit of FU is in error, it has no effect on the decision of NU first
bit. Hence, there are two situations: The FU first bit is error-free and in error.
Case 1: When FU is error-free at NU, from Figure 4, yields:
7. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
99
2 1
2 1
correct Pr
2 2
a I
P P
P n h
(4.6)
2 1
2 1
correct Pr
2 2
b I
P P
P n h
. (4.7)
After SIC process, the reference constellation for NU is given in Figure 5 [12, 13]
Figure 5. Reference constellation for NU after SIC when FU is error-free
From (4.6), (4.7) and 5, the error probabilities of NU are conditional probabilities as
1 2 1
1 1 2 1 1
correct Pr
2 2 2
I I
P P P
P e n h n h
(4.8)
1 2 1
1 2 2 1 1
correct Pr
2 2 2
I I
P P P
P e n h n h
. (4.9)
Applying Bayes’ theorem, we have the total error probability of NU if FU is detected correctly
1 2 2 1 1 2 2 1 2 2
1 2 1 1
1 1 1
1 1 2 1
1
0 0
1
correct correct correct correct correct
2
1
Pr Pr
2 2 2 2 2
1
2
a b
I I
P P P e P P e
P P P P
h n h n h
P h P P
Q Q h
N N
.
(4.10)
Case 2: When FU is in error at NU, from Figure 4, we have:
2 1
2 1
error Pr
2 2
a I
P P
P n h
(4.11)
8. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
100
2 1
2 1
1
error Pr
2 2 2
b I
P P
P n h
. (4.12)
Assume that the first bit of UE2 being transmitted is 0’ but detected as 1’, after the SIC process,
the reference constellation of NU is given in Figure 6.
Figure 6. Reference constellation for NU after SIC when FU is erroneously detected
From (4.11), (4.12) and Figure 6, the error probability of NU when FU is in error consists of
2 1 2 1
1 1 2 1 1
2
error Pr
2 2
2
I I
P P P P
P e n h n h
(4.13)
2 1 2 1
1 2 2 1 1
2
error Pr
2 2
2
I I
P P P P
P e n h n h
. (4.14)
In a similar way to (4.10), the total error probability of NU when FU is erroneously detected is
obtained as
1 2 2 1 1 2 2 1 2 2
2 1 2 1 2 1
1 1 1
2 1 2 1 2 1
1 1
0 0 0
1
error error error error error
2
2 2
1
Pr Pr
2 2 2 2
2 2
1 1 1
2 2 2
a b
I I
P P P e P P e
P P P P P P
n h h n h
P P P P P P
Q h Q h Q
N N N
1 .
h
(4.15)
From (4.10) and (4.15), the total error probability of NU is followed by
9. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
101
1 1 2 1 2
1 1 2 1 2 1
1 1
0 0 0
2 1 2 1
1 1
0 0
correct error
1
2
2 2
1
.
2
P e P P
P h P P P P
Q Q h Q h
N N N
P P P P
Q h Q h
N N
(4.16)
Define some notations
2
1 1
0
C
P h
N
2
1 1
0
C
P E h
N
(4.17)
2 2
2 1 1
0
D
P P h
N
2 2
2 1 1
0
D
P P E h
N
2 2
2 1 1
0
E
P P h
N
2 2
2 1 1
0
E
P P E h
N
2 2
2 1 1
0
2
F
P P h
N
2 2
2 1 1
0
2
F
P P E h
N
2 2
2 1 1
0
2
G
P P h
N
2 2
2 1 1
0
2
.
G
P P E h
N
.
Hence, the average BER of NU over quasi-static Rayleigh channel is expressed as
1
1 1
1
2 4
2 2 2 2 2
C G
D E F
C D E F G
P e
. (4.18)
5. BER IN MUST CATEGORY 2
Figure 7 shows the reference constellation to detect signals at each UE when using MUST
category 2. Red bits denote FU’s bits, and black bits are NU’s bits. The order of bits is ascending,
where the most significant bit is leftmost and is stated as the first bit. Gray-coded mapping is
conserved for adjacent symbols.
10. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
102
Figure 7. Reference constellation at the receiver when using MUST cat.2
5.1. BER of Far User
For MUST cat.2, from Figure 7, mapping rules for FU’s bits remains unchanged comparing to
MUST cat.1. Therefore, BER expressions of UE2 in this case are identical to (4.3) and (4.5).
5.2. BER of Near User
In this section, authors proposed another approach to analyze BER of NU, different from Section
4.2 and [10-13]. For UE1, error probabilities depend on the last two bits of a symbol. As a result
of constellation symmetry and equal prior probabilities, the third and fourth bits are the same in
error probabilities. The third bit is in error when one of these cases happens
2 1
2
1 1 0
2 2
I
P P
P
h n h
2 1 2
1 1
2
2
I
P P P
n h h
(5.1)
2 1 2
1 1
0
2
2
I
P P P
n h h
2 1 2
1 1
2
2
I
P P P
n h h
.
The error probability of NU calculated from (5.1) is
1 1 2 1 2 1
1 3 1 1
0 0 0
2 2
1
.
2
b
P h P P P P
P e P e Q Q h Q h
N N N
(5.2)
And the average BER expression of NU over the quasistatic Rayleigh channel is given by (5.3),
with notation in (4.17)
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103
1
1 1
1
2 4
2 2 2
C G
F
C F G
P e
. (5.3)
If we use the above approach for MUST cat.1, UE1 BER expressions obtain the same result as
(4.16) and (4.18)[12, 13]. Compare (4.16) and (5.2) or (4.18) and (5.3), a BER expression of
MUST cat.2 has only three out of five components of MUST cat.1, hopefully leading to lower
BER.
6. BER IN MIMO-NOMA
As derived in Section 3.2, we have the equalized signal, more specifically expressed as[19, 21]
1
1
2
H H
m
m
ZF
m z h h
m h z . (6.1)
Each receiving antenna has two data streams that are perfectly separated when the channel is not
correlated with the ideal ZF. Now consider the effect of ZF on AWGN. We have the singular
value decomposition (SVD) for the MIMO 2x2 channel is H
h UΣV , where 2x2
U and
2x2
V are unitary matrices, 2x2
Σ is a rectangular matrix whose diagonal elements are non-
negative real numbers and whose off-diagonal elements are zero. The diagonal elements of Σ are
the singular values of the matrix h , denoting them as 1
, 2
, so 2
1
and 2
2
are eigen values.
Then, (6.1) can be rewritten
1
2
1
2
1
1
.
H H H H
H
H
m
m
m
m
UΣV UΣV UΣV
VΣ
z
U
m
z
(6.2)
From (6.2), for uncorrelated MIMO channels, eigenvectors are linearly independent leading to
their singular values are non-zero and non-repeated, the expected value of noise power at fixed
eigen values is given as [21]
2 2 2
2
2
2 2 2
MIMO
1 1 2
z z z
i i
E
ZF
z . (6.3)
If 2 2
1 2
, equation (6.3) can be approximated
2 2
2
2
2 2
MIMO
1 1
z z
i i
E
ZF
z . (6.4)
From (6.4), we can see that each antenna in the introduced MIMO encounters the same effect as
SISO channel with the corresponding eigen value 2
1
. If the condition number of the channel
matrix is getting larger than a threshold, then the minimum singular value is very small, which
makes the approximation be more precise. For MIMO T R
N N
channel matrix where T R
N N
denoting the number of transmit and receive antennas respectively,
2 2 2 2
min 1 2
min , ,..., T
N
,
followed by (6.5)
12. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
104
2 2
2
2 2
MIMO
1 min
T
N
z z
i i
E
ZF
z . (6.5)
7. NUMERICALAND SIMULATION RESULTS
In this section, the authors used Monte Carlo simulation over independent symbols to verify all
proposed expressions, under different power allocation ratios and MUST types corresponding to
the model in Figure 1 and Figure 2. Simulation parameters are specified in Table 1.
Table 1. Simulation parameters for single tap fading channels
Parameter Value
UE1’s average channel gain
2
1 1
E 1
g
h
UE2’s average channel gain
2
2 2
E 0.5
g
h
Power allocation ratio
0.2;0.3
Single antenna transmission power 1
S
P
Channel information Perfectly known at receivers
Equalization method ZF
Fading channel
Single-tap Rayleigh
SISO, uncorrelated MIMO
Figure 8 shows the BER results when using MUST cat.1 in SISO-NOMA systems where 0.2
and 0.3
, corresponding to
1 2
; 0.2;0.8
P P and
1 2
; 0.3;0.7
P P respectively. All
proposed expressions perfectly match the simulation results for both cases, as equation (4.5) for
UE2 and equation (4.18) for UE1. Under given channel conditions, BER of two users in 0.2
is better than 0.3
. At optimum power allocation, if increasing , which decreases UE2’s
power allocation coefficient, it leads to the degradation of the BER in UE2. In such a case,
although UE1 is allocated more power, its BER is not better but on the trend of getting worse, the
reason is that UE1’s symbol detection depends on UE2’s decoding.
Figure 8. BER of two users in SISO-NOMA using MUST cat.1 with different power allocation ratios
13. International Journal of Computer Networks & Communications (IJCNC) Vol.13, No.6, November 2021
105
Figure 9 changes to MUST cat.2 in MIMO-NOMA systems with 0.2
and 0.3
. Results
show that MIMO has the same BER performance as SISO under certain restraints, with BER of
UE1 using equation (5.3), while UE2 using (4.5). Using MUST cat.2 with 0.3
, BER of UE1
is almost superior to UE2 when 0
b
E
N is larger than 2 dB, while in the case of 0.2
, to achieve
that, 0
b
E
N needs to be larger than 15 dB. The reason for this is MUST cat.2 ensures Gray-coded
mapping for composite constellations maximum a single-bit error for sufficient 0
b
E
N , if allocating
more power to UE1, we are “protecting” UE1 more than UE2. Compared to Figure 8, MUST
cat.2 is also better than MUST cat.1.
Figure 9. BER of two users in MIMO-NOMA using MUST cat.2 with different power allocation ratios
Figure 10 shows the results when the SISO channel has multiple taps, we need to scale the
analytical expression SNR, but due to error in limited ZF equalization causing ISI, simulations
barely fit derived BER formulas. When the system is combined with OFDM (see Table 2 for
parameters), BER curves match the expressions due to ISI elimination in cyclic prefixes. It is
noteworthy that SNR must be scaled for OFDM signals.
Table 2. Simulation parameters for two-tap fading channels
Parameter Value
UE1’s average channel gain
2
1 1
E 1
g
h
UE2’s average channel gain
2
2 2
E 0.5
g
h
Power allocation ratio 0.2
Single antenna transmission power 1
S
P
Number of FFT points 64
Number of data subcarriers 52
Number of zeros 1 DC, 11 guard bands
Number of cyclic prefixes 16
Channel information Perfectly known at receivers
Equalization method ZF
Fading channel Rayleigh SISO 2 taps
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106
Figure 10. BER of two NOMA users in SISO-ZF-OFDM and SISO-ZF systems using MUST cat.1
8. CONCLUSION AND FUTURE WORK
This research has introduced BER expressions for downlink MIMO-NOMA-ZF systems using a
SIC receiver, serving two users with QPSK modulation over an uncorrelated quasi-static
Rayleigh channel. Simulation results are perfectly matched with analytical expressions, not only
in different power allocation ratios but also MUST type 1 and 2 for signal generations. The
results show that MUST type 2 has better performance than type 1 due to Gray-mapping rules,
and when combined with OFDM, the system can minimize ISI, the simulations fit well with the
proposed theory. An approach to compare the performance between SISO and MIMO in the
NOMA system has also been clarified.
When the channel is bad or there is no need for high data rate, we can consider using diversity
instead, such as space-time coding, or develop a machine-learning detection system to ensure
integrity. Future work can be conducted for higher modulation orders, antenna beam forming,
optimal power allocation, MMSE or different equalization techniques, increasing the number of
users, having non-linear effects, and over correlated channel models.
CONFLICT OF INTEREST
The authors declare no conflict of interest.
ACKNOWLEDGMENT
This research is funded by Vietnam National University HoChiMinh City (VNU-HCM) under
grant numberC2019-18-32.
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AUTHORS
Vu Tran Hoang Son received a B.S. degree in Electronics and Telecommunications,
minor in Telecommunications and Networks, from the University of Science, Vietnam
National University, HoChiMinh City (VNU-HCM). He is focusing on new-generation
mobile networks and wireless communications.
Dang Le Khoagraduated B.E. and Ph.D. in Radio Physics and Electronics from
University of Science, Vietnam National University, HoChiMinhCity (VNU-HCM). He
is the head of the Telecommunications and Networks Department, University of Science,
VNU-HCM. His current research interests are in the areas of wireless communications
and digital signal processing for telecommunication.