SNR Estimation Based on Metric Normalization Frequency in Viterbi Decoder

Signal-to-noise (SNR) estimation plays an important role in modern wireless communication systems because an accurate SNR value can aid the improvement of transmission performance in various aspects. In this letter, we propose a estimation method of noise variance based on the normalization frequency of path metric in Viterbi decoder, and the channel gains are evaluated by the least squares estimation and the energy estimator. Then, we derive the SNR from the ratio of the estimated channel gain to the estimated noise variance. The simulation results show that the proposed algorithm can estimate SNR more accurately than previously published SNR estimators.