TDD-CDMA uplink capacity investigation in the background noise floor

Many system load evaluations have been proposed, and some applications, such as admission control strategies, have been discussed. It is observed, however, that, due to the TDD-CDMA specialization in the uplink (UL), i.e., multiuser detection (MUD) technology is used and the transmission is discontinuous per frame, all those schemes which are based on the FDD mode should be carefully investigated for the TDD system. The well-known formulation of UL background noise rise (BNR) for FDD-CDMA is modified and enhanced, and a modified BNR is presented for TDD-CDMA. Pole capacity, load and capacity estimation of the UL based on modified BNR are all described. The distribution of the parameter, j, which is used to define the ratio of other cell to own cell interference, is discussed based on the picocell scenario. Finally, in order to demonstrate the efficiency of the load strategy for TDD-CDMA, an admission control strategy based on modified BNR is evaluated and simulated. All works demonstrate that modified BNR gives a very good representation for capacity and load estimation in TDD-CDMA systems.