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Use of Code Division Multiple Access (CDMA) in conjunction with slotted ALOHA improves throughput since some of the "collided" packets can be retrieved, although at the expense of enlarged bandwidth. In view of the feasibility of recovery of packets, such schemes are attractive to carry receiver-to-transmitter acknowledgement (ACK) traffic also. The presence of ACK traffic is known to significantly reduce the throughput of slotted ALOHA channels. In this paper, the impact of such ACK traffic on the performance of slotted ALOHA-CDMA schemes is examined in detail for both finite and infinite terminal population. Also, a new performance index called "figure of merit" is introduced, which is very useful in comparing the joint delay-throughput-bandwidth performance of different CDMA schemes.