Patent ID: 7496159

Claim:
A survivor path decoding apparatus for a Viterbi decoder with a constraint length of K, comprising: a best survivor unit for receiving path metrics of 2 K−2 local winner states from which a best state is selected every L iterations_said local winner states are chosen from 2 K−2 pairs of odd and even states, respectively; and a survivor memory comprising: a register-exchange network for receiving decision bits of 2 K−1 states and generating decision vectors of survivor paths leading to said 2 K−1 states at instant i according to said decision bits of said 2 K−1 states from instant i−L to instant i, wherein said 2 K−1 states are divided into said 2 K−2 pairs of odd and even states, said decision vectors of said 2 K−1 states are output every L iterations, and each of said decision vectors has a length of L bits; and a trace-back unit for storing said decision vectors of said 2 K−1 states and finding a global survivor path sequence by following said decision vectors back from the best state at instant i−L, such that L decoded bits are output every L iterations.