Patent ID: 7644346
Filing Date: 2010-01-05
Classification: H04L

Abstract:
1. A method of assessing an encoded signal to locate a format in a plurality of candidate formats that was likely used to arrange the signal into blocks before the encoding was done, the method comprising: performing a test on candidate formats in turn but refraining from testing further candidate formats once a candidate format passes the test, wherein the test determines whether or not a candidate format is likely to be the format used on the signal and the test, for a given candidate format, comprises: using a Viterbi algorithm to determine trellis metrics for a point in said signal that would be an end point of a candidate block according to the given candidate format; determining from said metrics the likelihood of occupation at said point of an end state of an encoding scheme used to create the encoded signal; decoding a part of said signal ending at said point; and performing a check using said decoded part to determine whether the candidate block satisfies an error protection scheme of the given candidate format.