Throughput of spread-spectrum systems with a large number of users

Gives throughput results in terms of capacities per unit bandwidth for a multiaccess spread-spectrum communication system with a large number of users. Various spread-spectrum users are included. The direct sequence scheme with a sinc pulse as the chip pulse gives the maximum throughput of log/sub 2/ e(=1.44) bit/Hz. The frequency hopping schemes with M-ary frequency-shift keying have the smallest throughput; assuming detection with side information, for M=2 the throughput is equal to that of slotted ALOHA (e/sup -1/) and decreases as M increases.