Reducing the bit-mapping search space of a bit-interleaved polar-coded modulation system

The bit mapping pattern has a crucial effect on the error performance of a bit-interleaved polar-coded modulation (BIPCM) system. In this paper, we have shown that a large proportion of the mapping patterns are producing the same error performances and are hence redundant as far as mapping optimization is concerned. An effective method is then proposed to eliminate the redundant mapping patterns and the optimal pattern is found within the substantially reduced search space. Results show that the mapping optimized by the proposed method can further improve the block error performance compared to existing mapping schemes.