Lasting Successive-Cancellation based Decoders for Multilevel Polar Coded Modulation
Ludovic Chandesris, Valentin Savin, David Declercq · 2018
This paper investigates a new approach to decoding (higher order) multi-level polar coded modulations (MLCM). In general MLCM, bit-levels are encoded and decoded separately, thus leading to a delicate “rate-allocation” task. In this paper, we show that the structure of Successive Cancellation (SC)-based polar decoders, such as SC-List or SC-Flip, can be efficiently exploited to improve the decoding performance. Instead of considering each bit-level separately, the proposed lasting decoders work continuously along all the bit-levels. At the cost of a slight increase of the complexity, these decoders offer significantly better performance, and make the rate-allocation problem very simple. Finally, it is shown that multi-level polar coded modulations offer a clear advantage as compared to bit-interleaved polar coded modulations.