| 摘要 |
PROBLEM TO BE SOLVED: To shorten a coefficient update interval of an adaptive filter applied to a delay wave canceler for canceling a delay wave of a desired wave due to a multipath, radio wave wraparound or the like. SOLUTION: A cancel residual calculating part for calculating a frequency characteristic showing the cancel residual component of the delay wave included in an output signal of a subtracter and calculating a filter coefficient for the adaptive filter with the cancel residual component is provided with an FFT circuit for converting an input signal from the subtracter into data of a frequency domain and outputting the data, a data distribution circuit for dividing the data of the frequency domain into respective data for a plurality of domains and outputting the data for the plurality of domains, a plurality of residual frequency characteristic calculation circuits for parallelly calculating a frequency characteristic showing the cancel residual component from the data of the frequency domains inputted from the data distribution circuit in each of the circuits, a data combination circuit for combining and outputting respective signals from the residual frequency characteristic calculation circuits, and an IFFT circuit for applying inverse fast Fourier transformation to the frequency characteristic data from the data combination circuit to generate a filter coefficient for update. COPYRIGHT: (C)2004,JPO
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