Communication apparatus and communication method

摘要

A modulator generates a modulation signal from an input signal by, and a serial-parallel converter generates a subcarrier modulation signal from the modulation signal. A shifter shifts a predetermined data series to generate a shift sequence. Two IFFT units perform an IFFT on data sent thereto to generate first data and second data. An operator generates baseband signals from at least one of the sum of the first data and the second data and the difference therebetween. The foregoing processing is repeated with a predetermined number of times to shift the predetermined data series being changed. A PAPR determiner sends the baseband signal matching with a predetermined reference for determining a transmission signal to a transmitter. The transmitter generates a transmission signal from the baseband signal, and transmits the transmission signal to another communication apparatus via an antenna.

主权项

1. A communication apparatus for communicating with another apparatus in orthogonal frequency-division multiplexing wireless communication, the communication apparatus comprising:
a modulator that modulates an input signal by a predetermined modulation scheme, and assigns the modulated input signal to subcarriers with frequency components orthogonal to each other, thereby generating a subcarrier modulation signal; a first transformer that performs an inverse fast Fourier transformation on the subcarrier modulation signal to generate first data; a shifter that shifts a predetermined data series which is a set of data in a predetermined direction by a predetermined number of times to generate a shift sequence, the predetermined data series having an autocorrelation property such that an autocorrelation value of the predetermined data series with a data series whose data has not been shifted is higher than an autocorrelation value of the predetermined data series with a data series whose data has been shifted; a second transformer that performs an inverse fast Fourier transformation on the shift sequence to generate second data; a calculator that respectively generates baseband signals from the first data and data obtained by adding the second data to the first data and data obtained by subtracting the second data from the first data, and calculates a PAPR (Peak-to-Average Power Ratio) of each of the baseband signals; wherein processes of the shifter, the second transformer, and the calculator are repeated with the predetermined number of times to shift the predetermined data series being changed, until detection of a baseband signal whose PAPR matches with a predetermined reference, or until completion of one cycle of shifting of the data in the predetermined data series, and wherein the communication apparatus further comprises a transmitter that generates a transmission signal from that of the generated baseband signals which matches with a reference for determining the transmission signal, and transmits the transmission signal.