This paper proposes a power control algorithm with fast convergence suited for wideband code division multiple access (WCDMA). Conventional algorithms are developed with continuous mode power control not binary mode power control. The new power control algorithm is suggested to support the binary mode power control and to offer the optimal relaxation factor for fast convergence.

The reverse link bandwidth efficiency of a spectrally overlapped CDMA system with fast transmit power control is evaluated to find the optimum overlapping, where the bandwidth efficiency is defined as the maximum aggregate bit rate of all subsystems per unit bandwidth (bps/Hz). Single and multiple cell environments are considered. Besides the rectangular chip pulse, the impact of a pulse-shaping filter is discussed. It is found that the raised cosine spectrum pulse shaping helps to increase the bandwidth efficiency and strict pulse shaping filter problem can be avoided if a large number of subsystems are overlapped. It is also found that the optimum carrier spacing remains unchanged irrespective of the power delay profile shape of the multipath channel, whether multipath fading exists or not, and whether a single cell or multiple cell system is considered. However, the bandwidth efficiency strongly depends on them and the impacts of the related parameters are discussed.