Two-Way Relaying Using Constant Envelop Modulation and Phase-Superposition-Phase-Forward

In this paper we propose the idea of Phase-Superposition-Phase-Forward (PSPF) relaying for 2-way 3-phase cooperative network involving constant envelop modulation with discriminator detection in a time-selective Rayleigh fading environment. A semi-analytical expression for the bit-error-rate (BER) of the system is derived and comparison with one-way relay is made. Preliminary results indicate that 2-way relaying with PSPF suffers only a moderate loss in energy efficiency (of 1.25 dB) when compared to its one-way relaying counterpart. We attribute the loss to non-optimal power allocation amongst the three nodes in the system. On the other hand, PSPF improves the transmission efficiency by 33% and it offers a way to avoid expensive linear power amplifiers and complicated signal processing at the relay. It is thus a viable alternative to some of the 2-way relaying techniques in the literature.