Cooperative Versus Receiver Coded Diversity with Low-Complexity Encoding and Decoding

The amplify-and-forward (AF) and the decode-and-forward (DF) cooperative coded diversity is compared with the conventional receiver coded diversity in terms of the bit error rate (BER). The comparison assumes channel coding with non-binary modulations, and fast fading channels with path-loss attenuation proportional to the distance between nodes. Numerical results obtained by extensive computer simulations suggest that, for our path-loss system model, the AF diversity outperforms the receiver diversity provided that the relay is closer to the source and to the destination than the distance between the source and the destination. This condition can be satisfied more easily provided that there is more than one relay about the source, and for higher order modulations. In addition, the BER performance of the DF relaying is found to be more sensitive to the relay location than the BER performance of the AF relaying.