ARQ strategies for relay cooperative systems

We propose two novel automatic repeat request (ARQ) strategies for relay cooperative system over Rayleigh fanding channel: one uses relay ARQ and the other destination ARQ. The BER performace of these two strategies is derived in fast block fading. Numerical analysis and simulation show the systems can get more performace gain when the inter-channel (the source to the relay) quality is bad in the relay ARQ strategy. In the destination ARQ strategy, when the uplink qualities of the source and relay to the destination are poor, the average received SNR of the destination is much low, the systems performce can be improved efficintly.