Method and apparatus for determining scaling factors in fixed-point decoder

Abstract

Data from a communications channel is decoded by receiving data bits corresponding to encoded data, determining a set of data representations from the data bits, distributing the set of data representations into bins across a dynamic range to generate a distribution of the data representations, assigning a respective intermediate scale factor to each bin, deriving a set of moments from the intermediate scale factors, combining the moments into a scaling factor, scaling the data representations by the scaling factor, and sending the scaled data representations to a decoder. The data representations may be a histogram or cumulative distribution function of log-likelihood ratios (LLRs) or values based on channel estimates. In an iterative implementation performed until a stopping condition is met, the data representations may be scaled down on later iterations to avoid saturation. A correction factor may be applied to update the scaling factor for later data bits.