Performance measures for satellite-to-land-mobile communication systems using spread spectrum

Abstract

Absbract:A direct-sequence spread-spectrum satellite-Wand-mobile communications system is analyzed with respect to fading/multipath effects in Rayleigh or R i c h faded multiple-access environment with an unfaded, Rayleigh, and Riaan faded desired user. Numerical results employing Gold codes of lengths 31 and 127 for all three fading cases of the desired user are presented in terms of tight lower and upper bounds of the bit error probability as wen as user capacity. The latter performance measure is represented by the minimum required SNR for a specified acceptable bit error probability versus the number of users in the system. Conclusions on the fadinglmultipath effect on the number of simultaneous users of the satellite-toland-mobile communications system are drawn from the numerical results.