Icom Incorporated

Nobuyoshi Nishikawa

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.

Communication apparatus and communication method

A communication apparatus comprises an inserter that inserts an element having a value of 0 or nearly 0 into a predetermined position of a modulated signal to generate inserted data; an operator that adds a pilot signal comprising a data series of which the elements at the positions corresponding to the predetermined positions in the modulated signal are multiplied by a first amplitude coefficient and the elements other than the elements multiplied by the first amplitude coefficient are multiplied by a second amplitude coefficient to the inserted data to generate a post-operation data; an IFFT unit that performs IFFT on the post-operation data; and a transmitter that generates a baseband signal based on the post-operation data on which the IFFT is performed and transmits a transmission signal generated from the baseband signal.

The communication apparatus comprises a modulator that modulates an input signal to generate a modulated signal; an inserter that inserts a predetermined element into the modulated signal at a predetermined position to generate inserted data of which the number of elements is equal to a size of Fast Fourier Transformation (FFT); a calculator that calculates Peak-to-Average Power Ratio (PAPR) of a baseband signal corresponding to the inserted data; and a transmitter transmits a transmission signal corresponding to the baseband signal based on the calculated PAPR.

An identification provider provides predetermined identification data to an input signal, and generates a first signal. A differential encoder performs a differential encoding of a data series that is an aggregate of data having a matching number of elements to that contained in the first signal, and generates a second signal. A modulator modulates each of the first and second signals using a primary modulation, and generates first and second modulated data. An IFFT calculator performs an inverse fast Fourier transformation on each of the first and second modulated data, and generates first and second inverse transformed data. A selector compares peak-to-average power ratios calculated by baseband signals associated with the first and second inverse transformed data, and selects a baseband signal having the lower peak-to-average power ratio. A transmitter generates a transmission signal based on the selected baseband signal, and transmits the transmission signal.

Communication device and communication method

A modulator generates a modulation signal from an input signal. A serial-parallel converter generates a subcarrier modulation signal from the modulation signal. An IFFT unit performs an inverse fast Fourier transformation on the subcarrier modulation signal, generating first data. A decomposer decomposes the first data into real data and imaginary data. An operator performs a predetermined operation using a predetermined threshold value, a boundary value and the real data, generating positive data and negative data. Another operator performs a similar operation on the imaginary data. A generator adds the positive data and negative data based on the real data, and adds the positive data and negative data based on the imaginary data, generating real operation data and imaginary operation data. A synthesizer synthesizes both operation data to generate a baseband signal. A transmitter generates a transmission signal from the baseband signal, and transmits it to another apparatus via an antenna.

A modulator generates a modulation signal from an input signal. A serial-parallel converter generates a subcarrier modulation signal from the modulation signal. An inserter inserts a transmission-side data series, generated by multiplying a data series having an autocorrelation property by a predetermined series amplitude coefficient, in a signal for synthesis, generated by multiplying the subcarrier modulation signal by a predetermined signal amplitude coefficient, in such a way that elements in the signal for synthesis and elements in the transmission-side data series are alternately positioned, thereby generating first data. An IFFT unit performs an inverse fast Fourier transformation on the first data. A separator generates a baseband signal based on first half data of an operation result from the IFFT unit. A transmitter generates a transmission signal from the baseband signal, and transmits it to another apparatus via an antenna.

A modulator subjects an input signal to primary modulation to generate a primary modulated signal. A transmitter generates and transmits a transmission signal based on a secondary modulated signal generated from the primary modulated signal. A retransmission request receiver receives a retransmission request that contains identification information. An operator uses a data sequence that is a set of elements of a same number as a number of elements in an input signal identified by the identification information and with element values of 1 or 0 to generate operation data whose elements are values of exclusive OR of respective elements of the input signal and respective elements of the data sequence that are at same positions as positions of the respective elements of the input signal. If a retransmission request receiver receives a retransmission request, the modulator and transmitter perform the above processing using the operation data as an input signal.

A modulator generates modulation signals from input signals. A combiner arranges subcarrier modulation signals based on the modulation signals in order thereby to generate a compound matrix. The shifter shifts elements of each row of the compound matrix to generate shift matrix. An IFFT calculator subjects the shift matrix to inverse fast Fourier transformation to generate inverse transformation matrix. A maximum detector detects a column with a highest peak-to-average power ratio among columns of the inverse transformation matrix. A minimum detector detects an inverse transformation matrix including a column with a lowest peak-to-average power ratio among columns of inverse transformation matrices detected by the maximum detector. A transmitter generates a transmission signal based on baseband signals generated from each column of the inverse transformation matrix detected by the minimum detector, and transmits the transmission signal.

A modulator generates a modulation signal from an input signal, and a serial-parallel converter generates a subcarrier modulation signal from the modulation signal. An IFFT unit performs an inverse fast Fourier transformation on the subcarrier modulation signal to generate first data. An operator multiplies respective elements of the first data by amplitude coefficients, and further adds dispersion coefficients to the multiplication result, the amplitude coefficients being real numbers other than 0 defined for the respective elements, at least one of the amplitude coefficients having a value other than 1, the dispersion coefficients being complex numbers defined for the respective components, and at least one of the dispersion coefficients having a value other than 0. Then, data symbols are generated based on a calculation result. A transmitter transmits a transmission frame including the data symbols to another apparatus via an antenna.

A modulator generates a modulation signal from an input signal, and a serial-parallel converter generates a subcarrier modulation signal from the modulation signal. An IFFT unit performs an inverse fast Fourier transformation on the subcarrier modulation signal, and a decomposer decomposes a calculation result into a real part data and an imaginary part data. A calculator applies a predetermined calculation with respect to each element the value of which is equal to or greater than a positive threshold value and each element the value of which is equal to or less than a negative threshold value among the real part data and the imaginary part data. A synthesizer synthesizes the real part data and the imaginary part data to generate a baseband signal, and a transmitter generates a transmission signal from the baseband signal, and transmits it to another apparatus via an antenna.

A series generator divides a data series having an autocorrelation property equally into a certain number to generate subdata series. A modulator multiplies a predetermined amplitude coefficient and a unique number by each element of the subdata series, respectively, and rearranges the subdata series and synthesizes the rearranged subdata series to generate the modulation data. An IFFT unit performs an IFFT on the modulation data. The calculator divides the calculation result equally into the certain number to generate the sub calculation results, and multiplies an equalization coefficient by each element of the sub calculation results. A synthesizer generates a baseband signal by arranging the sub calculation results, so that an arranged position corresponds to a position at the time of being divided equally, and synthesizing the arranged result. A transmitter generates the transmission signal and transmits it to another apparatus via an antenna.

A modulator performs a predetermined operation for making an absolute value of an operation result of at least one element of an input signal greater than 0 on the individual elements of the input signal. The modulator generates post-operation data by associating individual elements of the input signal with individual elements of a data series which is a set of pieces of data which are equal in number to the elements of the input signal and whose absolute values are equal to one another, and multiplying the individual elements of the input signal which are subjected to the predetermined operation by the elements of the data series. An IFFT calculator performs inverse fast Fourier transformation on the post-operation data, and a synthesizer synthesizes operation results from the IFFT calculator to generate a baseband signal. A transmitter generates a transmission signal from the baseband signal and transmits the transmission signal.

A modulator generates a subcarrier modulation signal from an input signal, a parallel-serial converter generates a subcarrier modulation signal from the modulation signal. An IFFT calculator performs reverse Fast Fourier Transform on the subcarrier modulation signal, and a separator separates a calculation result into real part data and imaginary part data. A real part calculator performs a calculation on each element of the real part data to generate real part post-distribution data. An imaginary part calculator performs the data processing on the imaginary part data in the same manner, and generates imaginary part post-distribution data. A combiner combines the real part post-distribution data and the imaginary part post-distribution data to generate a baseband signal, and a transmitter which generates a transmission signal from the baseband signal to transmit generated transmission signal.

The modulator creates modulated signals from input signals. The series/parallel converter creates subcarrier modulated signals from the remaining data and modulated signals. The arithmetic operator arranges and combines a first number of elements of the subcarrier modulated signals from the first one and a second number of elements of a data series from the first one each multiplied by a given amplitude coefficient to create arithmetic operation data. The IFFT executor executes the inverse fast Fourier transformation of the arithmetic operation data. The combiner creates baseband signals from the arithmetic operation results. The determiner calculates the peal-to-average power ratio of the baseband signals. The processing of the arithmetic operator to the determiner is repeated while changing at least one of given numbers until the baseband signals complying with a given criterion are detected. The transmitter creates transmission signals from the baseband signals and transmits the transmission signals via an antenna.

When a changer changes a communication parameter based on a channel characteristic, a selector selects a switch data sequence corresponding to the changed communication parameter. A serial-parallel converter performs a serial-parallel conversion on a switch data sequence. An IFFT unit performs an IFFT. A transmitter synthesizes a calculation result from the IFFT unit to generate data symbol, and generates a transmission frame based on the data symbol. The transmitter then transmits the transmission frame to a second apparatus. A receiver receives a transmission frame from the second apparatus to generate data symbol. An FFT unit performs an FFT on the data symbol to generate a parallel signal. If a correlator determines that a notification of the change in the communication parameter has been correctly transmitted based on an autocorrelation analysis of the parallel signal, a communication apparatus starts communication using the changed communication parameter.

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Osaka, Japan

Nobuyoshi Nishikawa