| 摘要 |
PURPOSE: A decorder using a CSI(Channel State Information) is provided to improve the performance of the decorder by applying the CSI for representing the distortion of data received by a convolutional encoding to a decoding process of received data. CONSTITUTION: A decorder is composed of a buffer(51), a branch metric computer(52), an ACS(Add-Compare-Select)(53), a pass memory(54), and a trace back unit(55). Herein, the buffer divides data (x) softly decided to each data Z1, Z2(or I,Q). And, the branch metric computer computes an Euclidean distance, which is a branch metric, between the data Z1,Z2 outputted from the buffer and each branch. The ACS selectively outputs a minimum state value by comparing passes of each state after adding the state value. Herein, the state value is accumulated in every shift after multiplying the CSI with the output of the branch metric computer. The pass memory feeds back the minimum state value to the ACS unit after outputting an optimum state signal, which is the pass having a minimum state value among the entire state values outputted from the ACS unit. Then, the trace back unit traces an optimum pass by using the optimum state signal for computing the survival pass value in an initial section amount survey sections. Therefore, a convolutional encoder is decoded into a bit before being encoded.
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