Error probability of digital communications using relay diversity over Nakagami-m fading channels

The (lower-bound) symbol error rate (SER) performance of cooperative digital communication schemes is investigated, where multiple dual-hop relays are invoked for achieving the cooperative diversity with the aid of the maximal ratio combining (MRC). A range of closed-form expressions are obtained for the probability density functions (PDFs) of the relay-channels' output signal-to-noise ratio (SNR). Accurate and approximated closed-form expressions are derived for computing the SER. Our study shows that, with the aid of the closed-form expressions obtained in this contribution, the SER performance of the relay-assisted digital communications schemes, which may employ various classes of coherent modulations, can be readily evaluated in the context of a variety of fading scenarios that the cooperative signals might experience.