A comparison of CDMA and NPCSMA for an indoor data network

An indoor communication system using direct-sequence spread-spectrum signaling is considered. CDMA (code-division multiple-access) and NPCSMA (nonpersistent carrier-sense multiple-access) are considered as multiple-access alternatives and are compared based on their throughput and delay characteristics. The advantage of multipath diversity is illustrated. For NPCSMA and CDMA, delay and code length, respectively, restrict the number of simultaneous accesses allowable. A hybrid scheme, NPCSMA-CDMA, based on code sharing by contention, is examined. This scheme offers high capacity, without requiring very long codes or exhibiting excessive delays. Throughputs that approach that of NPCSMA are observed.<
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