Multipath Diversity Reception of Spread-Spectrum Multiple-Access Communications

The analysis of a multipath-combining receiver for directsequence spread-spectrum communications through a specular multipath channel is developed. The analysis applies to systems that use quadriphase-shift-keyed, offset quadriphase-shift-keyed, minimum-shiftkeyed, or binary phase-shift-keyed modulation. The measures of performance are the signal-to-noise ratio and approximations to the error probability involving the signal-to-noise ratio. The performance of a multipath-combining receiver is determined not only for the case of a single transmitter, but also for the case of multiple interfering transmit, ters. Furthermore, the performance of the system is determined in terms of parameters of the signature sequences. These parameters can be used as guides in selecting signature sequences for the system. Results are also given for the case of randomly generated signature sequences.