Frequency-domain equalization and diversity combining for demodulate-and-forward cooperative systems

We propose a low-complexity single carrier frequency-domain equalizer and diversity combining for cooperative systems with demodulate-and-forward relaying over frequency-selective channels. At the relays, we apply the conventional frequency-domain linear equalizers and compute the output signal to noise ratios, which are used to calculate the normalized correlation coefficient for deriving an equivalent source-to-relay-destination (S-R-D) channel. At the destination, we propose the joint equalization and diversity combining receiver for symbol detection by utilizing the equivalent S-R-D channel. Finally, we demonstrate the superiority of the proposed scheme over the straightforward solution that ignores the decisions errors at the intermediate relays through simulations.