average of sixteen this increase in symbols by a factor of four produces a more stable rssi estimate with a smaller variance over time thus closed loop transmit power is more closely regulated between the base station and the mobile communication system the sir measurement circuit 132 produces an sir signal on lead 125 fig1 in response to the new rssi and the issi a comparison circuit 126 compares the sir signal to a target sir on lead 124 a result of the comparison is applied to tpc command circuit 130 via circuit 128 the tpc command circuit then applies an appropriate tpc symbol to transmit amplifier 134 for inclusion in the next transmit time slot this tpc symbol instructs a remote base station to preferably increase or decrease transmit power by 1 db tuning now to fig5 a there is a diagram of a first iteration of an iterative signal to interference ratio determination of the present invention average circuit 412 receives tree groups of four pilot symbols 416 418 from the current time slot 404 and the prior time slots 400 402 the averaging circuit produces an improved initial channel estimate of rayleigh fading from the predetermined state of these twelve pilot symbol amp the correction or demodulation circuit then uses this improved channel estimate to correct phase and magnitude of thirty.