Methods for decoding data in digital communication systems

Abstract

The present invention includes methods relating generally to communication systems. In decoding a sequence of symbols output by an encoder having a first constituent encoder and a second constituent encoder, where the output of these encoders correspond to unterminated trellises, a forward calculation is performed along each trellis to compute a forward state metric value for a first node of each trellis. Prior to performing a backward calculation along each trellis, a backward state metric value of a second node of each trellis is initialized to the forward state metric values of the corresponding first nodes of each trellis. Using these forward and backward state metric values, the sequence of symbols is decoded. Other embodiments include decoding terminated trellises in a similar manner, or dividing each trellis into smaller windows and processing the series of windows.

Dependencies are inferred from the claim text.