Minimized SER based power allocation for multi HDAF relay cooperative network using differential evolution algorithm

In this paper, a multi Hybrid Decode-Amplify-Forward (HDAF) relay cooperative network with perfect CSI in flat Rayleigh fading channel is considered. The closed form expression of SER (symbol error rate) with tight approximation is derived and compared with the simulation done in Matlab environment. Based on the lower bound of SER, power allocation with Lagrange multiplier method and Differential algorithm (DE) based power allocation schemes are proposed. With fixed source power, the relay powers are optimized with the proposed schemes by the power allocation factor. Further the impact of relay location on the SER performance is investigated. The performance gain of proposed power allocation schemes depend on the channel quality of source to relay and relay to destination links. It is observed that the proposed power allocation schemes outperform the equal power allocation scheme and DE based power allocation provides SER response close to power allocation with Lagrange multiplier method.