Throughput analysis of direct-sequence CDMA-ALOHA in a near-far environment

The steady-state packet throughput characteristics of a slotted direct-sequence CDMA-ALOHA system in a near-far environment are derived. The network users are assumed to be spatially distributed in a plane and a 1/r/sup 4/ propagation power loss law is used. An accurate approximation for the probability of successful packet transmission incorporating error-correcting block codes is given employing an improved Gaussian method. Results for effective packet throughput and network capacity are presented for various spreading factors and error-correcting codes.