Wireless Imaging Using Cooperative Diversity of Relay Networks
Transmit diversity generally requires more than one antenna at the transmitter.However, many wireless devices are limited by size or hardware complexity to one antenna. Recently, a new class of methods called cooperative communication has been proposed that allows radio terminals to jointly transmit their information to emulate an antenna array and exploit spatial diversity in wireless fading channels. For a variety of processing algorithms and transmission protocols, per- formance improvements in terms of transmission rate and reliability have been demonstrated. In cooperative wireless communication, we are concerned with a wireless network, of the cellular or ad hoc nature, where the wireless agents, which we call users, may increase their e®ective quality of service (measured at the physical layer by bit error rates, block error rates, or outage probability) via cooperation. This research work describes the performance of relaying protocol in terms of average symbol error probability. Moreover it describes the promising benefits of distributed space time block codes over Rayleigh and Nakagami-m fading channels in order to enhance the performance of data transfer in cooperative relay networks. In addition it describes how the diversity achievement has been ana- lyzed in wireless relay networks employing distributed-Alamouti scheme. Further- more the optimal power allocation algorithm has been developed which e±ciently improve the symbol error probability over the equal power allocation. Finally the region of interest (ROI)-based scheme for image transmission is examined over the wireless cooperative/fading channels which improves the performance of ROI compared to direct communication (non-cooperative) and conventional co- operative communications image transmission schemes. Matlab simulations and Mathematica results are presented which show the good contribution to the latest research in the domain of cooperative communication.
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