Crosscorrelation functions of DS codes and probability of error evaluations for a multiple access channel

We derive a computationally feasible closed form error expression for probability of error for a small multiple access DS-BPSK system operating in a Rayleigh fading environment. Two properties of the cross-correlation functions of the DS codes help reduce the number of error probability evaluations required when one considers all possible phase shifts of the users´ codes. Examination of the error rates for different phases of three maximal-length codes reveal that the probability of error is only weakly dependent on the phases