A Multiplicative and Constant Modulus Signal Based Network Coding Method Applied to CB-Relaying

In this paper, a new and simple arithmetic operation for network coding (NC) in wireless communication is proposed. It is built on the assumption of constant modulus signals with phase conveyed information such as PSK and employs, in contrast to classical NC finite field additions, a multiplicative NC operation. The benefit of the method is that it decouples the NC operation from forward error correction (FEC) and modulation imposed joint constraints and thus permits for greater flexibility to adapt code and modulation rates to different user. It may further reduce hardware (HW) complexity and cost for NC enabled relays and it may operate directly on (potentially noisy) baseband signals. The performance of the proposed NC method is examined in a three phase NC bi-directional relaying scenario and compared to a traditional four phase non-NC scheme illustrating performance benefits in the high signal to noise (SNR) region and its viability for the former.