Abstract: A turbo decoder employs max* term or max term maximum a priori (MAP) decoding of received, encoded data. Initially, MAP decoding is iterative and employs max* term computation of log-likelihood values at each iteration. Max* term computation includes computation of a max term and a logarithmic correction term. A bypass algorithm switches from max* term computation to only max term computation in later iterations with little or no degradation in decoder performance. The iteration selected for switching may be based on increasing intrinsic signal-to-noise ratio (SNR) of the iterative MAP decoding. Since, in general, fewer computations are required for max term computation than for max* term computation, switching between max* and max allows for reduced power consumption of a particular decoder implementation.

Abstract: A turbo decoder employs max* term or max term maximum a priori (MAP) decoding of received, encoded data. Initially, MAP decoding is iterative and employs max* term computation of log-likelihood values at each iteration. Max* term computation includes computation of a max term and a logarithmic correction term. A bypass algorithm switches from max* term computation to only max term computation in later iterations with little or no degradation in decoder performance. The iteration selected for switching may be based on increasing intrinsic signal-to-noise ratio (SNR) of the iterative MAP decoding. Since, in general, fewer computations are required for max term computation than for max* term computation, switching between max* and max allows for reduced power consumption of a particular decoder implementation.