Patent ID: 6697442
Filing Date: 2004-02-24
Classification: H03M

Abstract:
A Viterbi decoding apparatus for processing received P data and received Q data by a trace-back method to obtain decoded data, said received P data and said received Q data being obtained by carrying out convolutional coding of data which are received by a receiver, said Viterbi decoding apparatus comprising:branch metric producing means for computing a branch metric in accordance with said received P data and said received Q data; path metric register means for storing a cumulative metric of survivor paths; ACS circuit means for adding said branch metric entering that state to said cumulative metric of the connecting survivor for all the paths entering a state, comparing, selecting the largest metric for each state (in the case constraint length equals to K, the number of the states is the (kâˆ’1)th power of 2), outputting path-selecting information of each state every symbol time, and storing the selecting metric for each state as the cumulative metric(path metric) of the next proceding time unit; maximum path state number detector means for getting the state number to check the largest path metric among said the states; a plurality of path memory blocks for storing said path-selecting information of each state every symbol time, said path memory blocks being connected to one another so that a result of trace-back may become a starting point for starting said trace-back of a next path memory block when said trace-back is made, wherein each of said path memory blocks comprises a selecting-information register for storing state selecting information therein, said selecting-information register being a flip-flop type memory element; and selector means for selecting outputs of said path memory blocks to produce said decoded data.