An analysis of the effects of power control error within a direct sequence CDMA system for mobile radio

Direct sequence (DS) code division multiple access (CDMA) systems have previously been proposed as a high capacity multiple access technique for cellular mobile radio (Gilhousen et al. 1991). However, in order to maximise the number of users which may operate within this type of system it is necessary to jointly optimise the apparent signal to noise ratio (SNR) of each system user. This may be achieved by ensuring that the average received signal power level of each user is equal. This implies that the transmitter power of each user must be accurately controlled and that any error within the power control process will degrade system capacity. For this reason accurate power control is an essential aspect of any practical CDMA system. Within the paper the effect of errors within the power control process on the capacity of the uplink of a CDMA system is assessed