Performance Analysis And Outage Optimal Power Allocation Scheme For Opportunistic Cooperative Communication

A threshold based opportunistic relaying cooperative communication protocol has been analysed in this thesis. The relay is selected opportunistically to maximize the end-to-end signal to noise ratio received at the destination. The relay selection may be proactive and reactive. The underlying communication protocol at relay is decode and forward cooperation. At destination Maximal Ratio Combining(MRC) is done to exploit diversity. The statistics in terms of (PDF ) and (CDF ) have been derived and used for determining outage probability, symbol error rate(SER) and the diversity gain. The asymptotic high SNR approximation of outage probability for proactive non-threshold opportunistic relaying has been derived and shown that it is a tight upper bound for proactive threshold opportunistic relaying. The approximate outage probability has been minimized subject to fixed total power and outage optimal power allocation ratio has been derived for varying channel conditions at source and relay. The outage performance with perfect and imperfect channel state information(CSI) have been compared and from simulation result the diversity loss in case of imperfect CSI is clearly evident. A new performance metric probability of miss of best relay has been proposed to have a better insight on the affect of the performance when CSI is imperfect. Probability of miss is higher in proactive opportunistic relaying than reactive opportunistic relaying. To whom, for them I matter