Cooperative Multi-Antenna Relaying in Fixed Hybrid Relay Networks

Co-operative communication using relays can achieve spatial diversity, which improves the link quality in a wireless network. In this paper, the performance of an infrastructure based multi-antenna adaptive decode-and-forward cooperative relay network in presence of a m-Nakagami fading channel using Low Density Parity check (LDPC) code has been investigated. The bit error probability (BER) and outage probability performance has been evaluated, when received signals are coherently combined at both the relays with multi-antenna and destination using Selection Combining (SC) and Maximal Ratio Combining (MRC) schemes respectively. The effects of number of relay antennas (L) and number of relays on the system performance have been studied. The impact of decoding threshold and „m‟ parameter on bit error rate (BER) and outage probability have also been evaluated. Further a tradeoff between relay antennas and number of relay is also indicated. Key-Words: Low Density Parity check (LDPC) code, Amplify and forward (AD), decode and forward (DF), adaptive decode and forward (ADF), BER, outage probability, Loglikelihood ratio (LLR), end-to-end (E2E).