Patent ID: 6950975
Filing Date: 2005-09-27
Classification: H03M

Abstract:
1. A method of accelerating the convergence rate of a turbo decoder comprising: receiving an encoded data block at the turbo decoder, wherein the encoded data block comprises frames and wherein a frame comprises bits; decoding a frame; determining whether the decoded frame comprises bit errors; if the decoded frame does not comprise bit errors, then identifying the bits as verified bits; if the decoded frame comprises bit errors, then identifying the bits as unverified bits; representing the possible states of the turbo decoder as nodes on a code trellis, wherein each node comprises a state metric; identifying a node on the code trellis entered by a verified bit as a bound node and a node entered by an unverified bit as an unbound node; enhancing the state metric of a bound node by identifying invalid transition states to and from the bound node; generating extrinsic information at the unbound node based on the enhanced state metric of an adjacent bound node adjacent to the unbound node, wherein the extrinsic information precludes invalid transition states; and terminating the decoding of the encoded data block when each node of the code trellis is bound.