Parallel Concatenated Trellis Coded Modulation1

In this paper, we propose a new solution to parallel con- catenation of trellis codes with multilevel amplitude/phase modulations and a suitable bit by bit iterative decoding structure. Examples are given for throughput 2 and 4 bits/sec/Hz with 8PSK, 16QAM, and 64QAM modulations. For parallel concatenated trellis codes in the examples, rate 2/3 and 4/5, 8, and l6-state binary convolutional codes with Ungerboeck mapping by set partitioning (natural mapping), a reordered mapping, and Gray code mapping are used. The performance of these codes is within 1 dB from the Shannon limit at a bit error probability of lo-' for a given throughput, which outperforms the performance of all codes reported in the past for the same throughput.