Performance of trellis-coded direct-sequence spread-spectrum communications

Considers the application of trellis coding techniques to the problem of direct-sequence spread-spectrum multiple-access communication. The unique feature of the trellis codes considered is that they are constructed over the set of possible signature sequences rather than over some standard 2-D signal constellation. The resulting codes have a small number of signals per dimension. The authors present several examples of the trellis codes, and a specific method of implementation. They also present a detailed error analysis for this type of system, which employs recently developed techniques due to Lehnert and Pursley. They generate numerical results for several examples and conclude that the proposed trellis coded systems yield significant performance improvements over binary antipodal DS/SSMA systems