Pragmatic TCMs With General Cross-Type M-QAM Constellations

Abstract

Recent applications of pragmatic trellis-coded modulation (TCM) to the $\boldsymbol {2^{k}}$ -quadrature amplitude modulation (QAM) (where ${k}$ is an even integer) have been preferred to utilize the square-type constellations due to its simplicity for practical implementation. However, these schemes limit a degree of freedom in designing transceivers since the cross-type constellations cannot be used. In this paper, pragmatic TCM having cross-type $\boldsymbol {2^{k}}$ -QAM constellations with the odd integer ${k}$ ’s greater than 4 are proposed. The proposed work includes details on the transceiver structures of pragmatic TCM based on the required constellation remapping rules. In addition, the approximate bit error rates (BERs) of 32 ( $\boldsymbol {k=5}$ ) and 128 ( $\boldsymbol {k=7}$ )-QAM utilizing the proposed rules are analytically derived and their BER performances are evaluated by the Monte-Carlo simulation. Simulation results of comparable performances to the conventional TCM schemes confirm the validity of the proposed transceiver design and the soundness of the BER analyses for the cross-type M-QAM constellations.