SNR estimation for power control of cdma2000 forward fundamental channels

The estimation of signal-to-noise ratio (SNR) for power control of the cdma2000 forward fundamental channel is investigated. Power estimation of the signal component is based on the power control (PC) subchannel symbol whose power is independent of the vocoder frame rate which can vary. An effective method of removing PC bit modulation and equalizing channel variation is proposed to coherently combine PC symbols. Power estimation of the noise component is accomplished by a differential approach to reduce the effect of errors introduced by fading and by increasing the noise sample size. Performance of the estimation algorithm is verified through computer simulations. Results show that the long term average frame error rate (FER) performance of the proposed algorithm is less than 1.5 dB from that of perfect SNR estimation.