基于分层调制的物理层网络编码系统概率成形设计OA

Hierarchical modulation,a crucial technique for unequal protection of data streams based on their significance,is investigated for physical layer network coding(PNC)systems in two-way relay channels.Traditional shaping techniques,which utilize distribution matches for nonlinear shaping and decoding,are inadequate for PNC systems due to the incurred shaping loss when a uniform input distribution is employed.This study introduces a novel linear probabilistic shaping codebook approach that ensures a linear shaping and decoding process.An expression for the achievable rate of the shaped system is further derived.Simulation results demonstrate that the proposed linear shaping scheme achieves a shaping gain of 0.3 dB at low to medium SNR levels.