A Simple Symbol Estimation for Soft Information Relaying in Cooperative Relay Channels

This paper proposes Symbol-based Soft Forwarding (SSF) protocol for coded transmissions which is based on a simple proposed soft symbol estimation at relay nodes. We present a simple strategy of forwarding soft information based on a simple linear summation of likelihood functions of each symbol. Specifically, with SSF, we demonstrate that exclusion of decoding at the relays costs no significant performance loss. To validate our claims, we examine bit error rate (BER) performance for the proposed scheme against the baseline SF scheme through computer simulations. We find that the proposed scheme can obtain considerable performance gains compared to the conventional relaying protocol.