Performance Improvement of Non-Regerative Cooperative Relay Networks with Optimal Power Allocation and Adaptive M-QAM/M-PSK Modulation Over Generalized Fading Channels

Abstract

This paper analyzes the performance of Channel Side Information (CSI)-assisted cooperative amplify-andforward (CAF) relay networks that employ both the node placement (i.e., relay position) based optimal power allocation policy among collaborating nodes and adaptive M-ary quadrature amplitude modulation (M-QAM)/ M-ary phase shift keying (M-PSK KEYWORDSCooperative diversity, adaptive modulation, optimum power allocation, relay node placement MOTIVATIONThe increasing demand for wireless communication system in recent years has necessitated a need to improve the performance, reliability and data rate of wireless channels. To address these needs, several attempts have been made on each of these improvement areas. The broadcast nature of wireless transmissions has enabled a new communication paradigm known as "cooperative communication" where a source node communicates with a destination node with the help of one or more relay nodes to harness a new form of spatial diversity and combat the effect of multipath fading. Cooperative communication serves as an alternative to conventional space diversity technique (i.e., Multiple Input Multiple Output (MIMO) technique), as the size of communication nodes (i.e., mobile handheld devices or wireless sensors) may not accommodate multiple transmit and/or receive antennas. Cooperative diversity also referred to as a "distributed MIMO" provides additional reliability to the wireless system.