Abstract: The present invention relates to a method and apparatus for providing digital background calibration for mismatches in M-channel time-interleaved ADCs(TI-ADCs), more specifically providing a pure digital blind calibration technique for offset mismatch, gain mismatch and time mismatch, which are essentially incurred by utilizing a time-interleaved analog-digital converter in systems having to process data with high speeds. Wherein the offset mismatch and gain mismatch are corrected based on statistical characteristics of the digital signals which are sampled and outputted in channel by channel, and the time mismatch is corrected based on a derivative filter and a delay filter. Thereby the present invention relating to a method and apparatus for digital background calibration enables the hardware complexity to be reduced and the efficiency of hardware resource to be increased.

Abstract: An add-compare-select (ACS) arithmetic unit for a Viterbi decoder is provided.

Abstract: A pre-decoder applied to a turbo decoder for decoding a punctured turbo code. The turbo code consists of a data bit stream and a plurality of parity bit streams, parts of which are punctured. The pre-decoder has an arithmetic unit for calculating estimated parity bit streams by carrying out, with respect to the data bit stream, the same algorithm used by a turbo encoder to produce the parity bit streams, a comparison unit for comparing the plurality of parity bit streams with the estimated parity bit streams, and a recovery unit for substituting estimated parity symbols for corresponding punctured parts of the parity symbol streams when related non-punctured bits of the parity bit streams are identical with corresponding estimated non-punctured parity bits. The punctured parity symbols are recovered by the pre-decoder completely, or at least partially, and provided to the turbo decoder. Accordingly, the decoding performance of the turbo decoder is enhanced.

Abstract: An add-compare-select (ACS) arithmetic unit for a Viterbi decoder is provided.

Abstract: A pre-decoder applied to a turbo decoder for decoding a punctured turbo code. The turbo code consists of a plurality of parity bit streams, parts of which are punctured. The pre-decoder has an arithmetic unit for calculating an estimation value of the parity bit streams by carrying out a same algorithm with respect to the data bit stream which is used by a turbo encoder to produce the parity bit streams, a comparison unit for comparing the plurality of parity bit streams with the estimation value, and a recovery unit for substituting the punctured bits of the parity bit streams for bits of the estimation values corresponding to the punctured parts when the respective bits of the parity bit streams are identical with the bits of the estimation values corresponding to the punctured parts. The punctured parity symbols are recovered by the pre-decoder completely, or at least partially, and provided to the turbo decoder. Accordingly, the decoding performance of the turbo decoder is enhanced.