On Linear Physical-Layer Network Coding with Non-Identical Modulation

• Published in: IEEE Wireless Communications and Networking Conference : [proceedings] : WCNC pp. 1 - 7
• Main Authors: Chen, Qiuzhuo, Yang, Tao
• Format: Conference Proceeding
• Language: English
• Published: IEEE 29.03.2021
• Subjects: compute-and-forward; distance spectrum; Error probability; Fading channels; Modulation; Physical-layer network coding; Simulation; Spread spectrum communication; Transmitters; Wireless networks
• ISSN: 1558-2612
• DOI: 10.1109/WCNC49053.2021.9417472

Physical-layer network coding (PNC) is able to boost the error probability performance or throughput of a set of multi-source and multi-hop wireless networks. In this paper, we put forth a new asymmetric linear PNC (A-LPNC) scheme for the setup where the users are subject to non-identical power and modulation schemes. For deterministic channel, we show that given any unequal average symbol energy, the effective minimum distance of A-LPNC constellation can be made to be identical to the single-user minimum distance lower bound, translated into optimal error probability performance at a medium to high SNR. For fading channels, we show that the optimized network coding coefficients can be found and employed such that the effective minimum distance of A-LPNC is equal to the single-user minimum distance lower bound for integer channel gains. For real-valued channel gains, we present the optimal NC coefficients selection that minimizes the error probability of A-LPNC. These results are verified via simulations.