| 摘要 |
PROBLEM TO BE SOLVED: To provide a symbol judging apparatus for judging a symbol of a demodulation signal. SOLUTION: A reception IF signal output from an RF circuit 12 is received by a receiving portion 20. A frequency discriminator 14 converts a change in frequency of a received signal into a change in amplitude value and then outputs an analog demodulation signal. An A-D converter 200 converts the analog demodulation signal to a digital demodulation signal. A frequency correcting portion 22 detects a synchronization word from the digital demodulation signal, compares a received pattern of the detected synchronization word and a fixed pattern of the synchronization word which is held in advance as a known fixed pattern, calculates a difference in average amplitude value as a frequency deviation correction value, and adds the digital demodulation signal and the frequency deviation correction value to correct a frequency deviation of the digital demodulation signal. A symbol judging portion 202 judges a symbol of the digital demodulation signal with the frequency deviation corrected and then outputs the symbol on an output screen such as a PC 24. COPYRIGHT: (C)2009,JPO&INPIT
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