Delayed Bit Interleaved Polar Coded Modulation
Dekun Zhou, Kai Niu, Chao Dong · 2018
In the conventional bit interleaved polar coded modulation (BIPCM), there exist some mutual information losses due to neglecting the correlations between the bit levels by using the bit interleaver. Based on this, the delayed BIPCM (DBIPCM) architecture is proposed to reduce the information losses in this paper. In the DBIPCM scheme, only one encoder is adopted and the transmitted symbols convey bits from the codewords encoded at different time for each bit level determined by the preset delays, which is different from the BIPCM. As we know, the variance of the bit channel capacities is used to measure the polarization effect under the multilevel polar coded modulation (MLC-PCM) scheme. It is found that the DBIPCM can achieve a more significant polarization effect compared to the MLC-PCM with the same set partitioning (SP) mapping way due to an extra log2m polarization transform process for 2m-ary constellations. From the simulation results by using the 16PAM over the additive white Gaussian noise channels, it is shown that the DBIPCM with Gray mapping can achieve a better performance compared to the conventional BIPCM. In addition to this, the DBIPCM with SP mapping outperforms the MLC-PCM by up to more than 0.6dB.