Abstract:  A novel approach to determine the uplink capacity and load of time division duplex-code division multiple access system by using background noise rise is presented. According to the approach, the influence of multi-user detection factor can be determined, and the uplink capacity and load can be calculated by some close form expressions as frequency division duplex-code division multiple access scheme. By comparing our analytical results with static simulation results, we show that our analytical approach and the deduced expressions are very good math with simulations.

Key words: code division multiple access, time division duplex, uplink system capacity, background noise rise, uplink load