A Trellis-Coded Modulation scheme with 32-dimensional constant envelope Q2PSK constellation

Trellis Coded Modulation with 32-Dimensional Constant Envelope Q2PSK is presented in this paper. TCM combines coding with modulation in such a way that the Euclidean distance is maximized and conserves bandwidth by doubling the number of constellation points of the signal. This way bit rate increases but the symbol rate remains the same. Q²PSK is a spectrally efficient four dimensional modulation scheme which utilizes available signal space dimensions in a more efficient way than the two-dimensional schemes. Utilization of all available signal space dimensions improves the coding gain. To achieve efficient bandwidth utilization Q2PSK is proposed as a modulation technique for TCM. Multidimensional signal constellations have better tolerance to phase ambiguities and better trade-off between complexity and coding gain. To make use of the advantages of both multidimensional TCM and Q2PSK modulation technique, TCM scheme uses 32 dimensional Constant Envelope Q2PSK modulation. The 32-Dimensional Q2PSK is obtained by concatenating eight 4-Dimensional Q2PSK subsets which allows the creation of eight symbols in one processing period. The Bandwidth efficiency is increased without sacrificing BER performance and power efficiency.