survivor path memory management method using immediate traceback algorithm for Viterbi decoder and apparatus for the same

摘要

PURPOSE: A survivor path memory management method for a Viterbi decoder using an immediate traceback algorithm and an apparatus thereof are provided, which have a smaller survivor path memory size and a processing time delay practically. CONSTITUTION: According to the survivor path traceback method in a decoding process of decoding Viterbi algorithm, deciding vector(DV) data indicating a path selected by an add-compare-select unit is stored into (k+2) memory banks in a survivor path memory in sequence, where a variable "k" is an integer above 2 and a variable "L" is a time required for the survivor path to be merged into one path and L/k is an integer indicating a size of each memory bank. A start state before L unit time in a trellis diagram is determined, by performing k starting node numbers deciding operation using k starting node number deciding circuit(SNNDC). Then, a decoding to the survivor path starts immediately as to the memory bank where the storing of deciding vector data is completed before L unit time from a node number of each starting state being output per every L/k unit time in sequence, and L/k decoding data corresponding to the path decoded from the node number of each starting state is output in sequence for L/k unit time.