scholarly journals Rate Maximization Using Cooperative Ratio Over Rayleigh Fading Channels

2021 ◽  
Author(s):  
Lavanya Rajagopalan
Keyword(s):  
Power Allocation ◽  
Fading Channels ◽  
Cooperative Diversity ◽  
Spatial Diversity ◽  
Cooperative Transmission ◽  
Total Power ◽  
Destination Node ◽  
Equal Distribution ◽  
Power Simulation ◽  
Diversity Transmission

Cooperative Diversity transmission, a newly upcoming field in the area of wireless communication, has been receiving great attention. This diversity transmission exploits the spatial diversity created by antenna sharing to improve the performance of a wireless network. The working of a cooperative diversity system is such that a source node communicates with a destination node with the help of another partner node. One important question usually raised regarding the operation of this system is that of the amount of power allocation among partnering nodes. Initial stages of research in this area had assumed equal distribution of power resources between the nodes. This approach has been proven as clearly suboptimal. Several works to allocate power optimally are coming up. In this project, optimal power allocation is used as a key approach to analyze the rate performance of the system. This is done with the help of a parameter called cooperative ratio which is the ratio of the power used for cooperative transmission to total power. Simulation results to support the analysis have also been provided.

scholarly journals Rate Maximization Using Cooperative Ratio Over Rayleigh Fading Channels

2021 ◽  
Author(s):  
Lavanya Rajagopalan
Keyword(s):  
Power Allocation ◽  
Fading Channels ◽  
Cooperative Diversity ◽  
Spatial Diversity ◽  
Cooperative Transmission ◽  
Total Power ◽  
Destination Node ◽  
Equal Distribution ◽  
Power Simulation ◽  
Diversity Transmission

Cooperative Diversity transmission, a newly upcoming field in the area of wireless communication, has been receiving great attention. This diversity transmission exploits the spatial diversity created by antenna sharing to improve the performance of a wireless network. The working of a cooperative diversity system is such that a source node communicates with a destination node with the help of another partner node. One important question usually raised regarding the operation of this system is that of the amount of power allocation among partnering nodes. Initial stages of research in this area had assumed equal distribution of power resources between the nodes. This approach has been proven as clearly suboptimal. Several works to allocate power optimally are coming up. In this project, optimal power allocation is used as a key approach to analyze the rate performance of the system. This is done with the help of a parameter called cooperative ratio which is the ratio of the power used for cooperative transmission to total power. Simulation results to support the analysis have also been provided.

Power Allocation for Multi-Relay Nodes Based on Signal-Noise-Ratio

2011 ◽  
Vol 403-408 ◽  
pp. 2255-2258
Author(s):  
She Xiang Ma ◽  
Yuan Zhang
Keyword(s):  
Power Allocation ◽  
Cooperative Diversity ◽  
Destination Node ◽  
Relay Nodes ◽  
Signal Noise ◽  
New Space ◽  
Noise Ratio ◽  
Equal Power Allocation ◽  
Equal Power ◽  
Cooperative Nodes

In wireless communication system, the cooperative diversity is a new space diversity mode. Power allocation plan aiming at maximizing the signal-noise-ratio (SNR) for multi-relay cooperative nodes system is discussed. Diversity signals are combined by the maximum ratio at the destination node. The research results show that 1) when the received noise level at destination node is very low, it can be neglected; 2) when the power allocation coefficients are proportional to the square of the channel gains from the source node to the relay nodes, the SNR of system is maximized in the maximum ratio combination model; and 3) When the received noise at destination node cannot be neglected, the power allocation coefficients are correlative to the received noise at destination node, the amplifying coefficients and the fading coefficients. The SNR of system can be enhanced by using the plan compared with traditional equal power allocation plan.

Single-Carrier Frequency Domain Equalization for Broadband Cooperative Communications

2010 ◽  
pp. 399-427 ◽  
Author(s):  
Tae-Won Yune ◽  
Dae-Young Seol ◽  
Dongsik Kim ◽  
Gi-Hong Im
Keyword(s):  
Fading Channels ◽  
Cooperative Communications ◽  
Cooperative Diversity ◽  
Spatial Diversity ◽  
Block Type ◽  
Channel Tracking ◽  
Single Carrier ◽  
Space Frequency ◽  
Pilot Design ◽  
Network Form

Cooperative diversity is an effective technique to combat the fading phenomena in wireless communications without additional complexity of multiple antennas. Multiple terminals in the network form a virtual antenna array in a distributed fashion. Even though each of them is equipped with only one antenna, spatial diversity gain can be achieved through cooperation. In this chapter, we discuss relay-assisted single carrier transmissions extending conventional transmit diversity schemes. We focus on distributed space-frequency block coded single carrier transmission, in order to operate over fast fading channels. A pilot design technique is also discussed for channel estimation of this single carrier cooperative system, which shows better channel tracking performance than conventional block-type channel estimations. In addition, spectral efficient cooperative diversity protocols are presented, where the users access a relay simultaneously or transmit superposed data blocks. Interference from the other user is effectively removed by using an iterative detection technique.

A Simplified Power Allocation Method for Cooperative Communication Based on Internet of Things

2012 ◽  
Vol 195-196 ◽  
pp. 200-204
Author(s):  
Yi Li ◽  
Xiao Mei Fu ◽  
Quan Guo ◽  
Yi Lu
Keyword(s):  
Internet Of Things ◽  
Outage Probability ◽  
Power Allocation ◽  
Cooperative Diversity ◽  
Future Internet ◽  
Spatial Diversity ◽  
Search Method ◽  
Opportunistic Relaying ◽  
Allocation Method ◽  
Simulation Results

In order to combat multi-path fading across multiple protocol layers in the wireless networks effectively, cooperative diversity is developed with a virtual multi-antenna array, and spatial diversity can be achieved with the relaying. In this paper, we study an improved opportunistic relaying which could be applied to future Internet of Things. Simulation results shows it has better outage probability and spectral efficiency, and based on the model we propose a simplified power allocation method, which has close performance to the exhaustive search method. It has less calculation complexity and lower outage probability, which would be more applicable for future cooperative systems.

Jointly Optimal Precoder and Power Allocation for an Amplify-and-Forward Half-Duplex Relay System

2011 ◽  
Vol 1 (1) ◽  
Author(s):  
Leonardo J. Rodríguez ◽  
Nghi H. Tran ◽  
Tho Le-Ngoc
Keyword(s):  
Power Allocation ◽  
Cooperative Diversity ◽  
Relay Node ◽  
Total Power ◽  
Asymptotic Performance ◽  
Amplify And Forward ◽  
Coding Gain ◽  
Half Duplex ◽  
Single Relay ◽  
System Power

This paper investigates the optimal precoder design and power allocation between the source and relay for a half-duplex single-relay non-orthogonal amplify-and-forward (NAF) system. Based on the pair-wise error probability (PEP) analysis, an optimal class of 2 × 2 precoders is first derived for the traditional power allocation scheme, where one-third of the system power is spent at the relay node, while two-thirds are spent at the source node. Different from optimal unitary precoders proposed earlier, the derived class of precoders indicates that the source should spend all its power transmitting a superposition of the symbols in the broadcast phase, while being silent in the cooperative phase, for optimal asymptotic performance. We then further address the problem of jointly optimal precoder and power allocation for the system under consideration. It is shown that the total power should be equally distributed to the source and the relay, and the source should again spend no power during the cooperative phase for the best asymptotic performance. Analytical and simulation results reveal that the proposed precoders not only exploit full cooperative diversity, but also provide significant coding gain over the optimal unitary precoders. For instance, a coding gain of around 1dB can be attained at the practical BER level of 10 − 5 for various modulation schemes.

scholarly journals Joint Power Allocation for Coordinated Multi-Point Diversity Transmission in Rayleigh Fading Channels

Electronics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 101
Author(s):  
Min Lee ◽  
Seong-Keun Oh
Keyword(s):  
Power Allocation ◽  
Fading Channels ◽  
Rayleigh Fading ◽  
Numerical Results ◽  
Rayleigh Fading Channels ◽  
Joint Power ◽  
The Third ◽  
The Mean ◽  
Log Linear ◽  
Diversity Transmission

We consider the problem of joint power allocation (JPA) in a coordinated multi-point (CoMP) joint diversity transmission (JDT) network with a total coordination point power (TCPP) constraint, aimed at maximizing the ergodic cooperative capacity (ECC) in Rayleigh fading channels. In this paper, we first extend the JPA problem in the coordinated two-point (Co2P) JDT networkto the case of a non-unity TCPP constraint. Furthermore, we introduce more accurate log-quadratic approximated (LQA) expressions to obtain the coordinated transmission point (CTP) powers. Next, we extend our study to a coordinated three-point (Co3P) JDT network. Given the mean branch gain-to-noise ratios, we first obtain a log-linear approximated (LLA) expression for obtaining the optimum power of the third CTP (i.e., the worst quality-providing CTP). After obtaining the third-CTP power, we obtain the CTP powers of two better quality-providing CTPs by invoking the LLA CTP power expressions for Co2P JDT power allocation, under the remaining power given by the TCPP minus the third-CTP power. The numerical results demonstrate that the LQA and LLA CTP power expressions for Co2P JDT and the LLA CTP power expressions for Co3P JDT are very efficient in terms of the simplicity for JPA and CoMP set selection, as well as the resulting ECC.

scholarly journals Predictive Relay Selection: A Cooperative Diversity Scheme Using Deep Learning

2021 ◽  
Author(s):  
Wei Jiang ◽  
Hans Dieter Schotten
Keyword(s):  
Deep Learning ◽  
Fading Channels ◽  
Relay Selection ◽  
Cooperative Diversity ◽  
Spatial Diversity ◽  
Fast Time ◽  
Transmission Scheme ◽  
Opportunistic Relaying ◽  
Full Diversity ◽  
Slow Fading Channels

In this paper, we propose a novel cooperative multi-relay transmission scheme for mobile terminals to exploit spatial diversity. By improving the timeliness of measured channel state information (CSI) through deep learning (DL)-based channel prediction, the proposed scheme remarkably lowers the probability of wrong relay selection arising from outdated CSI in fast time-varying channels. It inherits the simplicity of opportunistic relaying by selecting a single relay, avoiding the complexity of multi-relay coordination and synchronization. Numerical results reveal that it can achieve full diversity gain in slow-fading channels and substantially outperforms the existing schemes in fast-fading wireless environments. Moreover, the computational complexity brought by the DL predictor is negligible compared to off-the-shelf computing hardware.

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