Packet error probability calculation in a direct sequence spread spectrum network

The author considers a multiple access communication system using direct-sequence spread-spectrum signaling as in a terrestrial packet radio network or a multiple-access satellite channel. A technique to characterize multiuser interference and background noise is introduced, and packet error probabilities are calculated. The multiuser interference over a packet in the network is modeled as a compound Gaussian multivariate random variable for moderate to large values of the processing gain. The conditional variance is dependent on the number of users and their interference powers. The best performance results, in terms of the expected total interference power, are obtained for the case of a large number of interferers with comparable interference powers. For small values of SNR (signal-to-noise ratio) the probability of error is smaller than that corresponding to Gaussian noise, and for large values of SNR it is larger