Patent ID: 6044116
Filing Date: 2000-03-28
Classification: H03M

Abstract:
A method for communicating systematic data bits using a prior bias information over a channel, the method comprising the steps of,generating an input block of data bits as the systematic data bits,repeating r time the systematic data bits as a repetitive systematic sequence,generating systematic tail bits,appending the systematic tail bits to the repetitive systematic sequence providing a systematic string,first data bit encoding the repetitive systematic sequence into first code bits,first tail bit encoding the systematic tail bits into first parity check tail bits, the first encoding step transits between defined states ending in an all zero state,appending the first parity check tail bits to the first code bits providing a first code string,second encoder interleaving the systematic string providing a second encoder interleaved string,second encoding the second encoder interleaved string into a second code string in interleaved order, the second code string, the first code string and the systematic string have equal length, the second encoding step transits between defined states not ending in an all zero state,transmitting the systematic string, the first code string and the second code string throughout the channel,receiving the second code string, the first code string, and the systematic string,first decoding the systematic string using the first code string and using the a priori bias information as bias information as a first a posteriori probability bias estimation providing a bias estimate,first decoder interleaving the bias estimate into an interleaved bias string,second decoder interleaving the systematic string into a decoder interleaved string,second decoding the decoder interleaved string using the interleaved bias string and the second code string providing interleaved updated bias information and interleaved data bit estimates,feed back deinterleaving the interleaved updated bias information into updated bias information,feeding back the updated bias information as the a-priori bias information for first decoding step,output deinterleaving the interleaved data bit estimates into data bit estimates,hard limiting the data bit estimates into values of zero and one,repeating the first decoding, first decoding interleaving second decoding interleaving, second decoding, feed back deinterleaving, feeding back, output deinterleaving and hard limiting steps a plurality of iterations for generating a repetitive output block of values as an estimate of the repetitive systematic sequence, andbit deleting 1/r times the repetitive output block of values into an output block of values as an estimate of the input block of data bits.