Design and robustness analysis of rotationally invariant SCTCM

This paper deals with the analysis and design of rotationally invariant (RI) serially concatenated trellis coded modulation (SCTCM) over AWGN channels. Several powerful RI-SCTCM codes are designed which are close to the capacity limit of the modulation constrained channel. Invariance to partial phase rotations is also investigated. Although it is shown that standard (i.e., non-concatenated) TCM codes are provably robust to phase rotations that only affect part of the coded sequence, this property is demonstrated for SCTCM codes only through simulations. A number of experiments were run to verify the expected performance of the designed codes. High order constellations, like 8-PSK and 16-QAM are used to obtain overall throughput on the order of 2-3 bits per channel use