COOPERATIVE COMMUNICATIONS COMBINATION DIVERSITY TECHNIQUES AND OPTIMAL POWER ALLOCATION EXPRESSION (original) (raw)

Performance Analysis Of Mimo Based Multi-User Cooperation Diversity Over Various Fading Channels

2010

In this paper, hybrid FDMA-TDMA access technique in a cooperative distributive fashion introducing and implementing a modified protocol introduced in [1] is analyzed termed as Power and Cooperation Diversity Gain Protocol (PCDGP). A wireless network consists of two users terminal , two relays and a destination terminal equipped with two antennas. The relays are operating in amplify-and-forward (AF) mode with a fixed gain. Two operating modes: cooperation-gain mode and powergain mode are exploited from source terminals to relays, as it is working in a best channel selection scheme. Vertical BLAST (Bell Laboratories Layered Space Time) or V-BLAST with minimum mean square error (MMSE) nulling is used at the relays to perfectly detect the joint signals from multiple source terminals. The performance is analyzed using binary phase shift keying (BPSK) modulation scheme and investigated over independent and identical (i.i.d) Rayleigh, Ricean-K and Nakagami-m fading environments. Subsequent...

Cooperative Diversity Using Optimal Relay Power Control for Different Fading Channels

2017 IEEE Wireless Communications and Networking Conference (WCNC), 2017

In this paper, we study the performance of a wireless communication system, where an arbitrary number of relays cooperate to enhance the signal between source and destination. The source and destination are hidden from each other, and there is no direct link between them. Optimal Relay Power Control (ORPC) is introduced as an effective scheme to achieve cooperative diversity, where there is a trade-off between complexity and system performance. This paper develops a new and more accurate model for the ORPC scheme and takes into account the effects of fading and thermal noise at both the relays and destination. This leads to the derivation of new analytical expressions for the overall spectral efficiency which can be used to estimate the throughput of the ORPC in Rayleigh and Nakagami-m fading channels, and to study the impact of different system parameters on efficiency. The accuracy of the new mathematical results is confirmed by Monte Carlo simulation. The results of this paper ca...

Performance Analysis of MIMO Relaying Channels’ Cooperative Diversity for Mobile Networks

Relay networks achieve high performance by utilizing cooperation between nodes which can classified as multi-hop networks and cooperative MIMO relaying networks. Cooperative diversity is a transmission technique to overcome fading, multipath and inter-channel interference. As an important part of "spatial diversity" systems, cooperative diversity involving multi hop data relays is a solution to improve propagation performance, expanding coverage and enhancing system capacity in such wireless environments. In a cooperative diversity system, the "third party" mobile devices acting as relays to help the main transmission link for improving the performance such as bit error rate (BER), data rate, coverage. This paper is a study of analyzing the system performance for MIMO-Relaying MIMO in different wireless channel and results show the better performance of cooperative communication.

Optimal power allocation in multi-relay MIMO cooperative networks: Theory and algorithms

2012

Abstract Cooperative networking is known to have significant potential in increasing network capacity and transmission reliability. Although there have been extensive studies on applying cooperative networking in multi-hop ad hoc networks, most works are limited to the basic three-node relay scheme and single-antenna systems. These two limitations are interconnected and both are due to a limited theoretical understanding of the optimal power allocation structure in MIMO cooperative networks (MIMO-CN).

Design and performance analysis of multiple-relay cooperative MIMO networks

In this paper, we propose a closed-form (i.e., without the need of any iterative procedure) joint optimization framework of the source precoder, the amplify-and-forward relaying matrices , and the destination equalizer for a cooperative multiple-input multiple-output (MIMO) wireless network. We study in depth such a design and carry out its performance analysis in terms of average symbol error probability (ASEP), which allows one to calculate the diversity order of the cooperative system. The ASEP is also evaluated via Monte Carlo simulations and compared with recent competitive alternatives. Results show that the proposed design performs better than or comparably to recently proposed iterative approaches , with lower computational requirements.

Network Parametric Analysis in MIMO-OFDM Using Multiuser Cooperative Relay

Cooperative relaying is a significant technique in wireless communication technologies .The cooperative relay network mainly enables to improvise the channel entities and assures an error free transmission. Cooperative relaying promises an enhancement in the channel capacity and throughput. However, relay selection, power allocation and subcarrier assignment seems to be complex issue in cooperative relay MIMO-OFDM system. Hence, in this article, an attempt has been made to design a novel algorithm for cooperative relay MIMO-OFDM system by selecting an appropriate relay with proper subcarrier assignment in-order to improve the performance metrics such as BER, channel capacity and throughput. In this algorithm, as a first step, the number of subcarriers is selected according to the average channel gains and the target rates of users. After that, the subcarriers are assigned to the users with the best equivalent channel gains along with the relay selection. Then the, multiuser cooperative relay algorithm is developed for analyzing the above-mentioned performance metrics. And, finally the multiuser cooperative relay algorithm developed for MIMO OFDM system is compared with two other algorithms such as Successive Convex Approximation (SCA) and Energy Harvesting Successive Convex Approximation (EH-SCA). It is evident that the cooperative relay algorithm provides a lower BER value and SNR for a balanced interference oriented environment compared to that of SCA and EH-SCA algorithms. The attributes of the cooperative network aims to increase the channel capacity and enhance the data rate requirements. The Decode and Forward (DF) relaying technique used in this work re-encodes and processes the data to ensure maximum throughput efficiency. The cooperative relay algorithm can be further extended mainly to wireless sensor networks and it can also be used to manage the power requirements in cooperative multiuser MIMO-OFDM networks.