Patent ID: 6836516
Filing Date: 2004-12-28
Classification: H03M

Abstract:
An apparatus for decoding a data symbol Xi of a plurality of data symbols Xi with subscript (i) having a value from (1) to (k) and (k) being a finite number, comprising:means for determining a data symbol initial estimate for all data symbols of said plurality of data symbols Xi for â€œiâ€  being equal from 1 to k, all data symbols of a plurality of data symbols Yi for â€œiâ€  being equal from 1 to k, and all data symbols of a plurality of data symbols Wi for â€œiâ€  being equal from 1 to k, wherein all data symbols of said plurality of data symbols Yi for â€œiâ€  being equal from 1 to k are produced in a transmitter in said communication system by a first convolutional encoding of all data symbols of said plurality of data symbols Xi for different values of â€œ1â€  between 1 and â€œkâ€ , wherein all data symbols of said plurality of data symbols Wi for â€œiâ€  being equal from 1 to k are produced in said transmitter by interleaving all data symbols of said plurality of data symbols Xi, or Xi and Yi for different values of â€œiâ€  between 1 and â€œkâ€  to produce all data symbols of a plurality of data symbols Zi for â€œiâ€  being equal from 1 to k, and a second convolutional encoding of all data symbols of said plurality of data symbols Zi for different values of â€œjâ€  between 1 and â€œkâ€  to produce all data symbols of said plurality of data symbols Wi for â€œiâ€  being equal from 1 to k; means for passing said estimates of data symbols Xi, Yi, and Wi for different values of â€œiâ€  between 1 and â€œkâ€  to a decision node, wherein said estimates of data symbols Xi, Yi, and Wi for different values of â€œiâ€  between 1 and â€œkâ€  passing to said decision node are determined according to said first and second convolutional encodings, wherein said estimates of data symbols Yi and Wi are in terms of estimates of data symbols Xi for different values of â€œiâ€  between 1 and â€œkâ€  based on said first and second convolutional encodings, thereby producing more than one occurrences of estimate of said data symbol Xi for different values of â€œiâ€  between 1 and â€œkâ€  at said decision node; means for determining a new estimate for said data symbol Xi for different values of â€œiâ€  between 1 and â€œkâ€  based on said initial estimate and each occurrence of estimate of said data symbol Xi for different values of â€œiâ€  between 1 and â€œkâ€  at said decision node based on said passing.