Multilevel trellis MPSK codes and rotationally invariant construction

Multilevel trellis codes (MLTC) have proved to be a bandwidth efficient coding technique that can achieve high asymptotic coding gain. Using a staged decoding process, these codes permit very good trade off between performance and complexity. Rotationally invariant multilevel trellis 8PSK codes are proposed to counteract phase instabilities in a bandlimited satellite communication system. By an appropriate partitioning of a 2*8PSK constellation, basic and generalized 45 degrees invariant codes, with 6.02 dB gain over uncoded QPSK, are constructed without bandwidth expansion. These codes outperforms all previously published single level TCM.<>