Hyundai Electronics Ind. Co., Ltd.

Dae-Il Oh

Won-Jin Lee

Dae-Hyun Kim

Eung-Ryeol Kim

Myung-Sik Kim

A traceback device of a trellis decoder including a memory for storing survivor path information as much as a decision depth, a multiplexing unit for decoding the survivor path information received from the memorizing unit, and a traceback unit receiving the survivor path information of lower bits decoded by the multiplexing unit and state output of itself, to carry out a state transition and trace back the decoded value of lower bits.

Trellis decoder for ATSC 8VSB

A trellis decoder uses a branch metric unit, an ASC unit, a maximum likelihood value detector, and a normalization unit in common by time-division method to realize a trellis coding interleaver used in a DTV. The trellis decoder includes path memories, state metric memories and traceback units each as many as required in the trellis coding interleaver.

Trellis decoder of a DTV

In an error data removing apparatus and method by decoding delay in a DTV system which employs a decoder of the VSB standard, respective segments or respective fields are divided into area 1 and area 2 using a starting point of decoded data as a reference to provide the decoded data of said area 1 section without involving delay and provide the decoded data of said area 2 section by delaying as long as a sync signal. A memory is utilized as the decoded data delay apparatus, and at this time, a value of a counter used for generating an address for reading/writing of the memory is utilized to delay the segment sync signal and field sync signal as required without separately using flip-flop or memory.

Apparatus and method for removing error data decoding delay in a DTV

A viterbi decoder includes a maximum branch metric value detecting device separated from a feedback loop consisting of an ACS arithmetic unit, a normalization arithmetic unit, and a state value storing device. In operation, a maximum branch metric value is detected by utilizing the output of the state value storing device, to thereby enhance operating speed. Further, a judgment is made as to whether a state having the minimum state value at an immediately preceding time is back-traceable from a state having the minimum state value at a current time by using survivor path information. Non-back-traceable non-correspondences are then detected, and the number of occurrences of non-correspondences are counted. If the occurrences of non-correspondences exceed a reference value, it is judged a non-synchronization. In another method, synchronization/non-synchronization is judged by detecting whether a trace back is possible, without utilizing survivor path information.

Viterbi decoder

A viterbi decoder includes a maximum likelihood state value detecting device separated from a feedback loop consisting of an ACS arithmetic unit, a normalization arithmetic unit, and a state value storing device. In operation, a maximum likelihood state value is detected by utilizing the output of the state value storing device, to thereby enhance operating speed. Further, ajudgment is made as to whether a state having the minimum state value at an immediately preceding time is back-traceable from a state having the minimum state value at a current time by using survivor path information. Non-back-traceable non-correspondences are then detected, and the number of occurrences of non-correspondences are counted. If the occurrences of non-correspondences exceed a reference value, it is judged a non-synchronization. In another method, synchronization/non-synchronization is judged by detecting whether a traceback is possible, without utilizing survivor path information.

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Kyoungki-do, South Korea

Dae-Il Oh