Improved relay selection for decode-and-forward cooperative wireless networks under secrecy rate maximization
Switch and Examine combining (SEC) diversity scheme is one of the simplest yet efficient diversity schemes. Earlier in  and , we proposed sequential power loading algorithm to reduce the average power used at the transmitter in transmit diversity systems. In this paper, we propose the usage of a maximum ratio combining (MRC) receiver on top of sequential power loading, and provide a complete performance analysis of this proposed scheme in terms of average power used, average number of used antennas, average feedback load, and outage probability. Numerical results show that the proposed MRC enhanced scheme provides lower average number of used antennas and average feedback load with better outage performance than post selection and early selection schemes that were proposed earlier. This improved performance comes at the expense of a slightly higher average transmit power used.