SIGNAL AND INTERFERENCE STATISTICS OF A CDMA SYSTEM WITH FEEDBACK POWER-CONTROL

Power control is essential in the use of direct-sequence code-division multiple-access (CDMA) techniques over fading radio channels. This pa per investigates a feedback power control approach that allows power c ommands to be updated at a higher rate than the rate of multipath fadi ng. The signal and interference statistics as received at the base sta tions after power control are obtained for a simulated CDMA system whi ch includes multiple base stations with diversity receivers and a larg e number of power-controlled users continuously moving at various spee ds. We show that often-used analyses based on perfect average power co ntrol lead to optimistic capacity results (by about 25%) because inter ference is underestimated by as much as 1 dB.