Samsung Electronics Co., Ltd.

Sung-han Choi

Jun-jin Kong

An apparatus for providing and storing a state metric which is used for an add-compare-select (ACS) operation in a Viterbi decoder using a number of ACS units in order to enhance decoding speed. A state metric memory in Viterbi decoder uses a two-port memory, in which a memory bank for reading and writing a state metric of a first half among the N state metrics generated in a ACS unit and two memory banks for alternately reading and writing the state metric of the second half whenever a codeword is input, are incorporated into a single memory. As a result, the storage capacity for storing the state metrics can be greatly reduced as compared to a conventional apparatus.

Viterbi decoder

A quality calculator apparatus for Viterbi-decoded data using zero-state metrics. The quality calculator for the Viterbi-decoded data includes: a Viterbi decoder which outputs zero-state metrics of input demodulated data according to the four possible transmission rates of FULL, HALF, QUARTER and 1/8; a register which stores respective zero-state metrics output from the Viterbi decoder; and a quality evaluation unit which reads the zero-state metrics stored in the register to evaluate the Viterbi-decoded data based on the zero-state metrics and which determines the actual transmission rate to be the one among the possible transmission rates which has the least zero-state metrics. The zero-state metrics of the demodulated data input to the Viterbi decoder are used as a quality evaluation parameter so that the quality evaluation can be correctly achieved to avoid errors in determining of the transmission rate, as compared to a quality calculator using a bit error ratio as the quality evaluation parameter.

Growing community of inventors

Suwon, South Korea

Sung-han Choi