Patent ID: 8630335

Claim:
A method for estimating a Signal to Noise Ratio (SNR) in a received signal comprising: for a fixed first set of a plurality of samples from the received signal, providing an initial noise estimate; starting with the initial noise estimate, iteratively improving the noise estimate using an iterative Expectation Maximization (EM) method comprising: (a) calculating a matrix of probability coefficients C i,j indicating probabilities of each one of a set of valid magnitudes μ j corresponding to each one of measured magnitudes y i of the samples, given the noise estimate; and (b) re-estimating the noise estimate to maximize a likelihood of obtaining the measured magnitudes y i , given the matrix of probability coefficients C i,j , the set of valid magnitudes, and the previous noise estimate; and repeating (a) and (b) until reaching a stop criterion; and estimating SNR based, at least partly, on the fixed first set of samples from the received signal and the noise estimate.