| 摘要 |
PURPOSE: A viterbi decoder is provided which judges a survival path by detecting the influence of an input word on an upper most bit. CONSTITUTION: A metric calculation part(110) calculates an error of a branch word by calculating the branch word of a demodulated input sequence, and generates a metric judgement bit by detecting the influence of channel noise on the upper most bit of the input word. An addition comparison calculation selection part(150) receives a new branch metric and an accumulated path metric and a metric judgement bit, and judges whether a difference of the sum of the branch metric and the accumulated path metric as to two paths lies within a range of generating an error, and determines a survival path using the inputted metric judgement bit according to the judgement result. A path memory part(160) stores the survival path and the metric being output through the addition comparison selection part. And a decoder(170) decodes output sequence corresponding to the actually transmitted sequence.
|
