Comparative study of cooperative networks with differential modulation

Cooperative networks have been considered for their spatial diversity benefit in wireless communications. The signal in the cooperative networks can be transmitted by a repetitive manner or using space-time codes. For both transmission schemes, we consider the error performance and resource allocation employing differential modulation which bypasses the channel estimation at the transceiver. We derive the error rate of the each scheme by adopting both decode-and-forward (DF) and amplify-and-forward (AF) relaying protocols. Then, three optimum resource allocations, i.e., energy, location, and joint energy and location, are carried out to minimize the error rate. Using these results, we compare the systems with different relaying protocols.