| 摘要 |
PURPOSE:To provide a reception device of a digital modulation signal, which can obtain a superior error rate feature in spite of the size of a moving speed of a reception device and in which a hardware scale can be reduced. CONSTITUTION:A frequency detection circuit 6 frequency-detects a digital modulation signal. An integral discharge filter 7 integrates a frequency detection output from the frequency detection circuit 6 for prescribed time. A decision unit 9 outputs demodulation output with a phase difference signal from the integral discharge filter 7 as judgement input. A feedback means consisting of an adder 8, a phase error extraction means 10, a delay circuit 11 and a constant multiplication circuit 12 extracts the phase error of judgement input, multiplies it by a constant, sets it to be noise correction quantity and feeds it back to judgement input. A constant variable means consisting of a moving speed measurement means 4 and a speed judgement circuit 5 controls the feedback means in accordance with the moving speed of the reception device and varies the constant. When moving speed is small, the constant is enlarged and it is reduced when moving speed is large. |
