Construction of trellis codes at high spectral efficiencies for use with sequential decoding

Sequential decoding of trellis codes at high spectral efficiencies is investigated and large constraint length trellis codes for two dimensional and four dimensional constellations are constructed for use with sequential decoding. It is shown that the channel cut-off rate bound can be achieved using constraint lengths between 16 and 19 with sequential decoding at a bit error rate of 10/sup -5/-10/sup -6/.