①(School of Information Science and Engineer, Yunnan University, Kunming 650091, China) ②(School of Software, Yunnan University, Kunming 650091, China)
In wireless communication network, the channel state information is complicated. A joint Hierarchical Modulation and Physical-layer Network Coding (HM-PNC) scheme is proposed for the asymmetric Two-Way Relay Channel (TWRC). In this scheme, the two source nodes and the relay node adopt the hierarchical modulation technology (2/4-PSK). In the relay node, a special demodulation/modulation and PNC mapping rule is designed. Corrupted by Additive White Gaussian Noise (AWGN), the relay Bit Error Ratio (BER) and the end-to-end BER expressions are derived. Simulation results show that the HM-PNC scheme not only improves the data rate in better links, but also takes into account the transmission reliability of the poor channels. Compared with the traditional QPSK-PNC scheme, the HM-PNC scheme has better mobile performance.
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