| 摘要 |
PROBLEM TO BE SOLVED: To provide a demodulator which is capable of exactly performing the decision of a code word. SOLUTION: This device is provided with a frequency detector 2 detecting the frequency of a modulation signal, phase detectors 3 and 4 detecting the phases of modulation signals, and a decoder 5 converting the signal into a preliminarily set cord word based on the frequency and phase detection results, performing the maximum likelifood decision of the converted cord word and decoding digital data based on the decision result. When the valid phase detection results can not be obtained by the phase detector 3 and 4, the decoder 5 sets phase candidates and converts them into the cord words and the decoder refers to the cord word having the possibility of being converted by the combinations of the frequency and plural phase candidates based on the detection result of the frequency detector 2 when the maximum likelihood decision is performed by using the converted cord words. |
