Performance of cellular SSMA with block coding under fading and multipath conditions

Considers the application of channel coding to cellular DS-SSMA digital radio. The method of moments is used to accurately assess the system error probability. Using this technique, one can also assess the accuracy of assuming that the multiuser interference has a Gaussian distribution, which allows calculations to be analyzed by simpler means. It is verified that the Gaussian assumption is sufficiently accurate under the conditions considered. Cellular system performance is further investigated with voice activity monitoring and cell splitting under AWGN, Rayleigh fading and multipath conditions typical for personal and mobile communications. Block codes of relative low complexity are investigated when Gold sequences of length 255 and 127 are employed for purposes of PN spreading. The average degradation due to interuser interference is determined by employing exact aperiodic correlation parameters as defined by Pursely [1977]. Numerical results indicate that for a given processing gain and number of interfering users, appropriate coding can allow for reliable communication even under multipath fading conditions