The present invention discloses a decoding path selection device for decoding codewords generated by convolutional codes or turbo codes encoders in error correction codes, the decoding path selection device comprising: a branch metrics calculation unit for receiving incoming signals and calculating branch metrics values; a programmable generalized trellis router for generating a decoding path control signal according to the turbo code or convolutional code specification employed by one of communications standards; a multiplexer for receiving the branch metrics values from the branch metrics calculation unit and the decoding path control signal from the programmable generalized trellis router and selecting a corresponding branch metrics value; a recursive calculation unit, connected after the multiplexer and for receiving the corresponding branch metrics value from the multiplexer; and an a-posteriori probability calculation unit, connected after the recursive calculation unit and for calculating a final decoding result.

A decoding circuit and a decoding method based on the Viterbi algorithm are provided. The decoding method includes the following steps: decoding an encoded data based on the Viterbi algorithm to generate a decoded data; performing error correction on the decoded data to obtain a data content of the encoded data; comparing the decoded data and the data content to generate bit correction information; using the encoded data to calculate multiple first branch metrics based on the Viterbi algorithm, the first branch metrics corresponding to a target bit of the data content; adjusting at least one of the first branch metrics based on the data content and the bit correction information to generate multiple second branch metrics; and selecting the first branch metrics or the second branch metrics based on the bit correction information.

Techniques are presented for mapping a digital data sequence into a signal point sequence for transmission. The signal point sequence belongs to a set of possible signal point sequences. In one example, a digital data sequence is received. Forbidden branch flags that forbid certain signal points in the possible signal points sequences are applied. The signal point sequence is selected from a subset of all the possible signal point sequences based on the digital data sequence. The subset is defined by the forbidden branch flags.

It provides a method (300) for polar decoding a received signal into a number, N, of bits with Successive Cancellation List, SCL. The method (300) includes: at the i-th level of a binary tree for decoding the i-th bit of the N bits, where 1≤i≤N: when the 1-th bit is an information bit, calculating (310) a path metric for each of 2*L.sub.i-1 candidate paths at the i-th level, where L.sub.i-1 is an SCL size at the (i−1)-th level and L.sub.0=1; setting (320) an SCL size at the i-th level, L.sub.i, based on L.sub.i-1 and a statistical distribution of the path metrics calculated for the 2*L.sub.i-1 candidate paths; and selecting (330) L.sub.i surviving paths from the 2*L.sub.i-1 candidate paths based on their respective path metrics.

A decoding circuit and a decoding method based on the Viterbi algorithm are provided. The decoding method includes the following steps: decoding an encoded data based on the Viterbi algorithm to generate a decoded data; performing error correction on the decoded data to obtain a data content of the encoded data; comparing the decoded data and the data content to generate bit correction information; using the encoded data to calculate multiple first branch metrics based on the Viterbi algorithm, the first branch metrics corresponding to a target bit of the data content; adjusting at least one of the first branch metrics based on the data content and the bit correction information to generate multiple second branch metrics; and selecting the first branch metrics or the second branch metrics based on the bit correction information.

It provides a method (300) for polar decoding a received signal into a number, N, of bits with Successive Cancellation List, SCL. The method (300) includes: at the i-th level of a binary tree for decoding the i-th bit of the N bits, where 1≤i≤N: when the i-th bit is an information bit, calculating (310) a path metric for each of 2*L.sub.i-1 candidate paths at the i-th level, where L.sub.i-1 is an SCL size at the (i−1)-th level and L.sub.0=1; setting (320) an SCL size at the i-th level, L.sub.i, based on L.sub.i-1 and a statistical distribution of the path metrics calculated for the 2*L.sub.i-1 candidate paths; and selecting (330) L.sub.i surviving paths from the 2*L.sub.i-1 candidate paths based on their respective path metrics.

Techniques are presented for mapping a digital data sequence into a signal point sequence for transmission. The signal point sequence belongs to a set of possible signal point sequences. In one example, a digital data sequence is received. Forbidden branch flags that forbid certain signal points in the possible signal points sequences are applied. The signal point sequence is selected from a subset of all the possible signal point sequences based on the digital data sequence. The subset is defined by the forbidden branch flags.

Methods and apparatuses are provided for operating a list Viterbi decoder. A path metric difference (PMD) threshold is set based on an input signal level and a PMD limit value. Decoding is performed by using the PMD threshold. Performing the decoding includes determining a PMD of a best path, comparing the determined PMD and the PMD threshold, and declaring a decoding failure and ending performing of the decoding, if the PMD is greater than or equal to the PMD threshold.

The present invention discloses a decoding path selection device for decoding codewords generated by convolutional codes or turbo codes encoders in error correction codes, the decoding path selection device comprising: a branch metrics calculation unit for receiving incoming signals and calculating branch metrics values; a programmable generalized trellis router for generating a decoding path control signal according to the turbo code or convolutional code specification employed by one of communications standards; a multiplexer for receiving the branch metrics values from the branch metrics calculation unit and the decoding path control signal from the programmable generalized trellis router and selecting a corresponding branch metrics value; a recursive calculation unit, connected after the multiplexer and for receiving the corresponding branch metrics value from the multiplexer; and an a-posteriori probability calculation unit, connected after the recursive calculation unit and for calculating a final decoding result.

A multi-mode viterbi decoder supporting different decoding modes. The viterbi decoder comprises circuitry to output one or more data symbol values. The circuitry sets the one or more data symbol values to a first quantity of unit intervals in a first decoding mode (e.g. PAM-4). The circuitry sets the one or more data symbol values to a second quantity of unit intervals in a second decoding mode (e.g. NRZ). The second quantity of unit intervals is greater than the first quantity of unit intervals. A branch metric circuit is adapted to, in the first decoding mode, generate a set of viterbi branch metrics based on the data symbol values for the first quantity of unit intervals. The branch metric circuit is adapted to, in the second decoding mode, generate the set of viterbi branch metrics based on the data symbol values for the second quantity of unit intervals.