SIGNAL TRANSMISSION APPARATUS AND SIGNAL TRANSMISSION METHOD
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Abstract
A signal transmission apparatus of the invention comprises: a correlator 12 for shaping a spectrum of a signal; and a precoder 12 disposed on a previous stage of the correlator and including an adder which subtracts an output signal of a feedback filter from an input signal, a modulo arithmetic unit which inputs an output signal of the adder and executes modulo arithmetic operation, and the feedback filter which inputs an output signal of the modulo arithmetic unit and is provided with a transfer function obtained by subtracting 1 from a transfer function of the correlator. The correlator may be IIR filter means having a desired notch characteristic. By disposing a correlator which can freely shape a transmission signal spectrum containing a deep notch and suppress only a specified band on a receiving side, the suppression of an external noise can also be realized.
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Citations
29 Claims
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1-14. -14. (canceled)
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15. A signal transmission apparatus for transmitting a signal while suppressing a transmission power or an external noise of a specified band in a usable frequency band, the signal transmission apparatus comprising:
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correlator means for shaping a spectrum of a signal into a spectrum containing a desired notch; and precoder means disposed on a previous stage of the correlator and including adding means which subtracts an output signal of feedback filter means from an input signal, modulo arithmetic means which inputs an output signal of the adding means and executes modulo arithmetic operation, and the feedback filter means which inputs an output signal of the modulo arithmetic means and is provided with a transfer function obtained by subtracting 1 from a transfer function of the correlator means. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A signal transmission method for transmitting a signal while suppressing a transmission power or an external noise of a specified band in a usable frequency band, the signal transmission method comprising:
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a step of inputting a result of subtracting an output signal of feedback filter means from an input signal and executing modulo arithmetic operation, and outputting resultant signals to correlator means and the feedback filter means having a transfer function obtained by subtracting 1 from a transfer function of the correlator means; and a step of shaping a spectrum of a signal into a spectrum containing a desired notch by the correlator means provided with a characteristic represented by the transfer function.
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22. A signal transmission apparatus for transmitting a signal while suppressing a transmission power or an external noise of a specified band in a usable frequency band, the signal transmission apparatus comprising:
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correlator means for shaping a spectrum of a signal; precoder means disposed on a previous stage of the correlator and including adding means which subtracts an output signal of feedback filter means from an input signal, modulo arithmetic means which inputs an output signal of the adding means and executes modulo arithmetic operation, and the feedback filter means which inputs an output signal of the modulo arithmetic means and is provided with a transfer function obtained by subtracting 1 from a transfer function of the correlator means; measuring means for measuring a frequency of a spectrum null point of a transmission channel; and adjusting means for adjusting the correlator means and the precoder means based on a measured notch frequency of the transmission channel. - View Dependent Claims (23, 26)
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24. A signal transmission apparatus for transmitting a signal while suppressing a transmission power or an external noise of a specified band in a usable frequency band, the signal transmission apparatus comprising:
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correlator means for shaping a spectrum of a signal; precoder means disposed on a previous stage of the correlator and including adding means which subtracts an output signal of feedback filter means from an input signal, modulo arithmetic means which inputs an output signal of the adding means and executes modulo arithmetic operation, and the feedback filter means which inputs an output signal of the modulo arithmetic means and is provided with a transfer function obtained by subtracting 1 from a transfer function of the correlator means; sweep control means for adjusting the precoder means and the correlator means so that a notch frequency moves at a speed which an equalizer on a receiving side can follow; transmission quality monitoring means for recording a transmission quality of a transmission channel together with a time position and detecting a time position in which the transmission quality is optimum; means for converting the time position to a notch frequency; and adjusting means for adjusting the correlator means and the precoder means based on the converted notch frequency. - View Dependent Claims (25, 27)
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28. A signal transmission method for transmitting a signal while suppressing a transmission power or an external noise of a specified band in a usable frequency band, the signal transmission method comprising:
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a step of measuring a frequency of a spectrum null point of a transmission channel; and a step of, based on the measured frequency of the null point of the transmission channel, adjusting correlator means for shaping a spectrum of a signal and precoder means disposed on a previous stage of the correlator and including adding means which subtracts an output signal of feedback filter means from an input signal, modulo arithmetic means which inputs an output signal of the adding means and executes modulo arithmetic operation, and the feedback filter means which inputs an output signal of the modulo arithmetic means and is provided with a transfer function obtained by subtracting 1 from a transfer function of the correlator means.
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29. A signal transmission method for transmitting a signal while suppressing a transmission power or an external noise of a specified band in a usable frequency band, the signal transmission method comprising:
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a step of adjusting precoder means for shaping a spectrum of a signal and precoder means so that a notch frequency moves at a speed which an equalizer on a receiving side can follow, the precoder means being disposed on a previous stage of the correlator and including adding means which subtracts an output signal of feedback filter means from an input signal, modulo arithmetic means which inputs an output signal of the adding means and executes modulo arithmetic operation, and the feedback filter means which inputs an output signal of the modulo arithmetic means and is provided with a transfer function obtained by subtracting 1 from a transfer function of the correlator means; a step of recording a transmission quality of a transmission channel on a receiving side and detecting a time position in which the transmission quality is optimum; a step of converting the time position to a notch frequency; and a step of adjusting the correlator means and the precoder means based on the converted notch frequency.
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Specification