Channel estimation technique with SNR measurement by minimum accumulated distance of Viterbi decoder

Abstract

This paper addresses channel estimation technique with SNR measurements for low SNRs. The LS estimator is simple and adequate for high SNRs, but the LMMSE estimator of assuming a priori knowledge of SNR value and channel covariance has a better gain over LS estimator for low SNRs. In this paper we propose an SNR measurement method with a little complexity by using minimum accumulated distance in Viterbi decoder. The measured SNR value is used in the LMMSE estimator and the performance is presented both in terms of mean square error and bit error rate compared to the LS estimator and the perfect channel state information case.