Performance of trellis coded direct-sequence spread-spectrum with noncoherent reception in a fading environment

We consider a different coding scheme for direct-sequence spread-spectrum (DSSS). The Nordstrom-Robinson (NR) code, a nonlinear code that has large distance for a given rate, used in conjunction with a trellis-code version is examined. A bound is developed on the error probability for this trellis coded Nordstrom-Robinson (TCNR) code with noncoherent reception over a frequency-nonselective Rayleigh or Rician fading channel with additive white Gaussian noise. This bound is tighter than a standard union bound. Our results indicate that the standard union bound can be significantly different from the more accurate results obtained from the improved union bound.