Radio communication system, radio transmitter and radio receiver
First Claim
1. A radio communication system adopting the OFDM scheme, comprising a transmitter and a receiver, the transmitter comprising:
- an amplitude measuring part for measuring an amplitude of a transmission signal on which inverse Fourier transform has been performed;
a power control part for outputting, based on the result of the measurement, control signals each for adjusting an amplitude of a signal on which inverse Fourier transform has not been performed, each signal corresponding to one of plural sub-carriers; and
multiple multiplying parts each for multiplying the amplitude of the signal by a multiplying number indicated by the control signal;
wherein the power control part outputs the control signal based on a product of an obtained signal that is obtained by performing Fourier transform on an output of the amplitude measuring part and the signal on which inverse Fourier transform has not been performed.
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Accused Products
Abstract
A radio transmitter adopting the OFDM scheme is disclosed. The radio transmitter includes an amplitude measuring part for measuring the amplitude of a transmission signal on which inverse Fourier transform has been performed; a power control part for outputting, based on the result of the measurement, control signals each for adjusting the amplitude of a signal on which inverse Fourier transform has not been performed, each signal corresponding to one of plural sub-carriers; and multiple multiplying parts each for multiplying the amplitude of the signal by a multiplying number indicated by the control signal. The power control part outputs the control signal based on a product of a signal pf(n) obtained by performing Fourier transform on an output of the amplitude measuring part and the signal sf(n).
39 Citations
9 Claims
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1. A radio communication system adopting the OFDM scheme, comprising a transmitter and a receiver, the transmitter comprising:
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an amplitude measuring part for measuring an amplitude of a transmission signal on which inverse Fourier transform has been performed;
a power control part for outputting, based on the result of the measurement, control signals each for adjusting an amplitude of a signal on which inverse Fourier transform has not been performed, each signal corresponding to one of plural sub-carriers; and
multiple multiplying parts each for multiplying the amplitude of the signal by a multiplying number indicated by the control signal;
wherein the power control part outputs the control signal based on a product of an obtained signal that is obtained by performing Fourier transform on an output of the amplitude measuring part and the signal on which inverse Fourier transform has not been performed.
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2. A radio transmitter adopting the OFDM scheme, comprising:
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an amplitude measuring part for measuring an amplitude of a transmission signal on which inverse Fourier transform has been performed;
a power control part for outputting, based on the result of the measurement, control signals each for adjusting an amplitude of a signal on which inverse Fourier transform has not been performed, each signal corresponding to one of plural sub-carriers; and
multiple multiplying parts each for multiplying the amplitude of the signal by a multiplying number indicated by the control signal;
wherein the power control part outputs the control signal based on a product of an obtained signal that is obtained by performing Fourier transform on an output of the amplitude measuring part and the signal on which inverse Fourier transform has not been performed. - View Dependent Claims (3, 4, 5, 6, 7, 8)
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9. A radio receiver that receives a transmission signal from a radio transmitter adopting the OFDM scheme, the radio transmitter comprising:
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an amplitude measuring part for comparing an amplitude of a transmission signal on which inverse Fourier transform has been performed with a threshold;
a power control part for outputting control signals each for adjusting an amplitude of a signal on which inverse Fourier transform has not been performed, each signal corresponding to one of plural sub-carriers, wherein the power control part outputs the control signal based on a product of an obtained signal obtained by performing Fourier transform on a transmission signal exceeding the threshold and the signal on which inverse Fourier transform has not been performed;
multiple multiplying parts each for multiplying the signal by a multiplying number indicated by the control signal;
wherein a second pilot signal is inserted into each signal that has not been multiplied by the multiplying number, and a first pilot signal in the frequency domain is inserted into each output of the multiple multiplying parts;
whereinthe radio receiver includes;
a channel estimation part for obtaining channel estimation values for all sub-carriers based on the received first pilot signal; and
a power control amount estimation part for obtaining a power control amount of a transmission signal based on the received second pilot signal.
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Specification