SNR Estimation Algorithm for Single Signal with Strong Multiple Access Interference

Abstract

Effective power control was required to improve system capacity and time synchronization accuracy of the CDMA earth station time synchronization networks. It usually uses the equivalent carrier-to-noise power ratio measurement for the CDMA communication system power control. As the receiver equivalent carrier-to-noise power ratio measurement was coupled of the multiple access interference, it cannot accurately estimate the strength of the earth station transmitting power. This paper analyzes the statistical characteristics of both the code tracking loop punctual channel measurements and the early-late phase discriminator channel measurements. By using the early-late phase discriminator output value, increased the multiple access interference noise observations. While using both the punctual channel equivalent carrier-to-noise power ratio and the early-late phase discriminator channels equivalent carrier-to-noise power ratio, we derive the estimate of single signal carrier-to-noise power ratio. The estimates accurately reflect the strength of earth station transmitting power, simulation results show that the algorithm has good estimation performance, both the estimated bias and the estimated standard deviation of the algorithm are less than 0.5 dB, providing high-precision observations for the earth station power control.