Patent ID: 6560745
Filing Date: 2003-05-06
Classification: G11B,H03M

Abstract:
A method of determining codeword boundary without marker bits, comprising the steps of:a) receiving a plurality of transmission bits ti, where i indicates bit position, where 1&lE;i&lE;L, where ti includes at least one codeword, where each at least one codeword includes k signal bits, and where each at least one codeword is n bits long; b) determining a dual code of a code used to generate the at least one codeword in ti; c) selecting a first vector from the dual code, excluding an all-zeros vector; d) initializing n scoring variables Sz each to zero, where 1&lE;z&lE;n; e) initializing i=1; f) initializing z=1; g) selecting n bits from ti, starting at bit position i; h) performing a bit-wise AND operation on the vector selected and the n bits selected from ti; i) if the result of step (h) contains an even number of ones then assigning a value of zero to the result of step (h), otherwise assigning a value of one to the result of step (h); j) setting Sz equal to Sz plus the result of step (i); k) if z is less than n, incrementing z and i each by 1 and returning to step (g), otherwise proceeding to the next step; l) if z=n, im) identifying the scoring variable Sz having the lowest score; and n) identifying the subscript z of the result of step (m) as the codeword boundary.