Orthogonal OQPSK Modulation with Physical Layer Network Coding Systems over Two-Way Relay

Physical-layer network coding (PNC) can reduce the required number of transmission time slots and increase network throughput. This study combines decode-and-forward (DF) and denoise-and-forward (DNF) in half-duplex two-way relay network (TWRN) using orthogonal offset quadrature phase shift keying (O-OQPSK) modulation under additive white Gaussian noise (AWGN) channels. This approach improves wireless network throughput by two and four times compared to ordinary PNC and conventional network coding schemes, respectively. First, we design the relay decoder in the denoise and decode forward (DNDF)-TWR scheme, relay denoising mapping and decoding functions in the TWR scheme, and decoder using the maximum likelihood (ML) principle. Then we analyse the relay bit error rate (BER) and end-to-end BER of the DNDF-TWR scheme with O-OQPSK modulation. Simulation results show that the BER performance of the DNDF-TWR scheme is better than that of DNF-TWR and DF-TWR schemes.