Abstract:
For asymmetrical channels, using the same modulation method at both ends of the communication system to send signals will cause problems such as high bit error rate and waste of transmission power. In the proposed scheme, a physical layer network coding scheme based on asymmetric modulation is designed. Firstly we propose the system model of the scheme and formulate the demodulation mapping rules at the relay node. Then we analyze the system under different power allocation ratios. Finally, we introduce the LDPC code as channel coding in the system, and design the corresponding decoding mapping scheme. Numerical results show that under asymmetric channel conditions, compared with the traditional symmetric modulation scheme, the decoding accuracy of asymmetric modulation scheme is improved by 7.6%.