Viterbi decoding method
A decoding method relative to this application improves an error correction performance without increasing a memory. The decoding method includes obtaining a first decoded result from a first decoding path being on a trellis diagram; determining whether the first decoded result is incorrect or not; creating a second decoding path when the first decoded result is incorrect; and obtaining a second decoded result from the second decoding path.
1 . A decoding method comprising:
obtaining a first decoded result from a first decoding path being on a trellis diagram;
determining whether the first decoded result is incorrect or not;
creating a second decoding path when the first decoded result is incorrect; and
obtaining a second decoded result from the second decoding path.
2 . The decoding method according to claim 1 , wherein
the first decoding path includes a first branch connecting a first state and a second state, the second state being at a time point previous to the first state and
the second decoding path includes a second branch connecting the first state and a third state, the third state being different from the second state and at a time point equal to the second state.
3 . The decoding method according to claim 2 , further comprising:
determining whether the second decoded result is incorrect or not;
creating a third decoding path when the second decoded result is incorrect; and
obtaining a third decoded result from the third decoding path.
4 . The decoding method according to claim 3 , wherein
the first decoding path further includes a third branch connecting the second state and a fourth state, the fourth state being at a time point previous to the second and third states and
the third decoding path includes the first branch and a fourth branch connecting the second state and a fifth state, the fifth state being different from the fourth state and at a time point equal to the fourth state.
5 . The decoding method according to claim 4 , wherein creating a new decoding path and obtaining a new decoded result are repeated till a correct decoded result is obtained.
6 . The decoding method according to claim 4 , wherein creating a new decoding path and obtaining a new decoded result are repeated predetermined number of times.
7 . The decoding method according to claim 1 , wherein the first decoding path has the highest likelihood in decoding paths being on the trellis diagram.
8 . The decoding method according to claim 1 , wherein the second decoding path has the second highest likelihood in the decoding paths.
9 . The decoding method according to claim 2 , wherein the first state is a final state being at a final time point of the trellis diagram.
10 . The decoding method according to claim 1 , wherein the first decoded result is obtained by performing a trace back on the trellis diagram.