Patent ID: 8495480

Claim:
An apparatus for signal-to-noise ratio (SNR) estimation in a convolutional codes decoder, the apparatus comprising: a branch metrics calculation unit, a path metrics and paths calculation unit and a decoded symbol generation unit, all connected in series; a minimal path metrics memory, a path metrics memory and a paths memory connected to the path metrics and paths calculation unit; a decoding path length estimation unit, where all paths calculated by the path metrics and paths calculation unit converge, the decoding path length estimation unit connected in series with an SNR estimation unit, wherein an input of the decoding path length estimation unit is connected to a first output of the paths memory, wherein a first output of the SNR estimation unit is connected to a first control input of the branch metrics calculation unit and to a control input of the path metrics and paths calculation unit, and wherein a second output of the SNR estimation unit is connected to a second control input of the branch metrics calculation unit and serves as a second decoder output that represents a current SNR estimate.