Patent ID: 7020214

Claim:
An apparatus for performing in-place path metric addressing for a trellis processing arrangement on an input sequence of a plurality of pairs of path metrics, each path metric being associated with one of a plurality of trellis states having a known order, to form a desired output sequence of path metrics corresponding to a desired older of the associated trellis states, the apparatus comprising: a plurality of first multiplexers, each first multiplexer for receiving one of said pair of path metrics and providing a first selected one of the received pair of path metrics based on a first signal; a plurality of latches, each latch coupled to a corresponding one of the first multiplexers for receiving the first selected one of the received pair of path metrics and configured to delay the first selected one of the received pair of path metrics based upon a delay signal; a plurality of second multiplexers, each second multiplexer for receiving said one of said pairs of path metrics and providing a second selected one of the received pair of path metrics based on a second signal; and a plurality of third multiplexers, each third multiplexer for receiving the delayed first selected one of the received pair of path metrics and the second selected one of the received pair of path metrics, and wherein each of the third multiplexers is configured to present one of the delayed first selected one of the received pair of path metrics and the second selected one of the received pair of path metrics based upon a third signal.