Performance Investigation of CDMA/PRMA with Imperfect Power Control in TDD Cellular Systems

This study investigates the performance of joint code-division multiple access/packet-reservation multiple access (CDMA/PRMA) with the consideration of imperfect power control in TDD-CDMA cellular systems, and compares with that of CDMA/PRMA with an assumption of perfect power control. Both voice and World Wide Web (WWW) Internet browsing traffic were considered. We have studied their performances in terms of packet loss probability, power outage probability and average access delay. The results show that the assumption of CDMA/PRMA with perfect power control is too optimistic and independent of cell radius. It might be valid when the cell radius is <500 m. In addition, the performance of CDMA/PRMA with imperfect power control is highly limited by the cell radius due to its constraint on transmission power levels. Therefore, careful study is required if CDMA/PRMA is used in TDD systems.