| 摘要 |
PURPOSE:To apply the system in every case in the system of multi-value QAM adopting the diversity and selecting method by arranging the difference of demodulation code series of M-sets at maximum to one of N-set of code series used as a reference and applying optionally switching and selection among the N-set of code series afterward. CONSTITUTION:Outputs of two demodulators are supplied individually to code converters 21, 21' to M-set states. The uncertain phase is detected by a code comparator 22 based on the difference of the code train, an integration device 23 discriminates its output whether it is a simple code error or a shift due to uncertain phase and its output drives an M-adic counter 24. The output of the M-adic counter is connected switchingly to the code converters 21, 21' via a switch 25. The switch 25 is thrown to the opposite position in response to a selector 15. That is, the uncertain phase is corrected by matching the remaining code train so as to be coincident with the code train selected at present and a continuous output data is obtained in switching the selector 15.
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