Abstract: Modulated signal A is transmitted from a first antenna, and modulated signal B is transmitted from a second antenna. As modulated signal B, modulated symbols S2(i) and S2(i+1) obtained from different data are transmitted at time i and time i+1 respectively. In contrast, as modulated signal A, modulated symbols S1(i) and S1(i)? obtained by changing the signal point arrangement of the same data are transmitted at time i and time i+1 respectively. As a result the reception quality can be changed intentionally at time i and time i+1, and therefore using the demodulation result of modulated signal A of a time when the reception quality is good enables both modulated signals A and B to be demodulated with good error rate performances.

Abstract: Modulated signal A is transmitted from a first antenna, and modulated signal B is transmitted from a second antenna. As modulated signal B, modulated symbols S2(i) and S2(i+1) obtained from different data are transmitted at time i and time i+1 respectively. In contrast, as modulated signal A, modulated symbols S1(i) and S1(i)? obtained by changing the signal point arrangement of the same data are transmitted at time i and time i+1 respectively. As a result the reception quality can be changed intentionally at time i and time i+1, and therefore using the demodulation result of modulated signal A of a time when the reception quality is good enables both modulated signals A and B to be demodulated with good error rate performances.

Abstract: A transmission signal processing method is provided, for generating a first OFDM modulation signal and a second OFDM modulation signal which are transmitted in an identical frequency band, by utilizing a first antenna for transmitting the first OFDM modulation signal and by utilizing a second antenna for transmitting the second OFDM modulation signal. The method includes a step of generating the first OFDM modulation signal and the second OFDM modulation signal utilizing a plurality of OFDM modulation signal generators, and a step of outputting the first OFDM modulation signal to the first antenna and the second OFDM modulation signal to the second antenna.

Abstract: A transmission apparatus includes a plurality of antennas and a frame configurator that selects, in a first unit time either a first transmitting method which transmits a modulated signal from at least one of the plurality of antennas, or a second transmitting method which transmits a plurality of modulated signals from the plurality of antennas, for a first carrier group arranged for a first terminal and either the first transmitting method or the second transmitting method for a second carrier group arranged for a second terminal. The frame configurator selects, in a second unit time either the first transmitting method or the second transmitting method for the first carrier group arranged for a third terminal and either the first transmitting method or the second transmitting method for the second carrier group arranged for a fourth terminal, wherein each of carrier groups includes one or more sub-carriers.

Abstract: A transmission method for transmitting modulation signals of a plurality of channels to the same frequency band from a plurality of antennas. At the time when a symbol used for demodulation is inserted in a channel, in another channel symbol, the same phase and quadrature signals in the in-phase-quadrature plane are made to be zero signals. Thus, a plurality of modulation signals are multiplexed and transmitted and the transmitted multiplexed modulation signals are demultiplexed and demodulated at a reception apparatus, thereby improving the data transmission rate.

Abstract: A transmitting apparatus includes a modulation signal generating section that generates a modulation signal by modulating transmission data using one of a plurality of modulation schemes. The plurality of modulation schemes include a first modulation scheme, a second modulation scheme, and a third modulation scheme, where the first modulation scheme has maximum m-ary modulation value, the second modulation scheme has a lower m-ary modulation value than the first modulation scheme, and the third modulation scheme has a lower m-ary modulation value than the second modulation scheme. The transmitting apparatus also includes a pilot signal generating section that generates a pilot signal having one of a plurality of amplitudes, the pilot signal having a lower amplitude than a maximum amplitude of the first modulation scheme.

Abstract: Soft decision sections provisionally decide each modulated signal separated using an inverse matrix calculation of a channel fluctuation matrix at separation section. Signal point reduction sections reduce candidate signal points of a multiplexed modulated signal using the provisional decision results. Soft decision sections make a correct decision using the reduced candidate signal points and obtain received data of each modulated signal. This allows received data RA, RB with a good error rate characteristic to be obtained with a relatively small number of calculations without reducing data transmission efficiency.

Abstract: A method for generating a transmission signal to transmit a modulated signal generated using orthogonal frequency division multiplexing, from a transmitting apparatus with a plurality of antennas, toward a plurality of terminals. The method includes assigning transmission data for the plurality of terminals to a plurality of carrier groups, each carrier group including a plurality of carriers and selecting, from the plurality of antennas, an antenna to be used for transmission toward each of the plurality of terminals. As a transmission mode for each of the plurality of carrier groups, a selection is made of one of a first transmission mode, in which one modulated signal is transmitted, and a second transmission mode in which a plurality of modulated signals are transmitted by using the selected antennas. A transmission signal is generated for transmitting the transmission data assigned to the plurality of carrier groups during an identical time period, using the selected transmission mode.

Abstract: A wireless communication apparatus and a communication control method wherein even if there occurs a change in communication control information due to a function change, an appropriate correction is implemented to improve the communication quality. A wireless communication apparatus (100) comprises a plurality of reconfigurable function parts (reconfigurable function modules (1031)) that reconfigure functions related to communication to perform digital signal processings according to a plurality of communication formats; and a communication operation control function part that controls the communication operation. Each of the reconfigurable function parts includes a property register (10311) in which the communication control information is written.

Abstract: A transmission method for transmitting modulation signals of a plurality of channels to the same frequency band from a plurality of antennas. At the time when a symbol used for demodulation is inserted in a channel, in another channel symbol, the same phase and quadrature signals in the in-phase-quadrature plane are made to be zero signals. Thus, a plurality of modulation signals are multiplexed and transmitted and the transmitted multiplexed modulation signals are demultiplexed and demodulated at a reception apparatus, thereby improving the data transmission rate.

Abstract: In a multivalue modulation type with one pilot symbol inserted for every 3 or more symbols, signal points of each one symbol immediately before and after a pilot symbol are modulated using a modulation type different from that for pilot symbols. In this way, it is possible to suppress deterioration of the accuracy in estimating the reference phase and amount of frequency offset by pilot symbols and improve the bit error rate characteristic in the signal to noise ratio in quasi-coherent detection with symbols whose symbol synchronization is not completely established.

Abstract: A wireless terminal involving small redundancy that can be reconfigured to a configuration compatible with a plurality of systems using the hardware resources compatible with one system is provided. A wireless terminal 100A is compatible with an OFCDM system and has a signal processing section 151, a synchronous detection section 162, etc. The signal processing section 151 performs Fourier transform when the wireless terminal is compatible with the OFCDM system; the signal processing section 151 performs Fourier transform and inverse Fourier transform compatible with an OFDM system when the wireless terminal is compatible with the OFDM system and a CDMA system. When the wireless terminal is compatible with the OFCDM system, the synchronous detection section 162 uses taps used in the systems when the wireless terminal is compatible with the OFDM system and the CDMA system.

Abstract: Provided is a fast Fourier transformation circuit capable of optimizing an operation resource while matching a plurality of communication systems. In this circuit, an FFT circuit (100) comprises a first FFT operation unit (110) for subjecting two-parallel 2<M?1> digital signals to FFT operations of (M?1) steps, a second FFT operation unit (120) for subjecting 2<N> digital signals to FFT operations of (N?M+1) steps, and a third FFT operation unit (130) for subjecting 2<M> digital signals to an FFT operation of one step. The output signal of the first FFT operation unit (110) is subjected to the FFT operation by the second FFT operation unit (120) and the third FFT operation unit (130) thereby to perform the FFT operations of 2<N> points and 2<M> points simultaneously.

Abstract: Soft decision sections (503, 506) provisionally decide each modulated signal (502, 505) separated using an inverse matrix calculation of a channel fluctuation matrix at separation section (501). Signal point reduction sections (508, 510, 514, 516) reduce candidate signal points of a multiplexed modulated signal using the provisional decision results (504, 507). Soft decision sections (512, 518) make a correct decision using the reduced candidate signal points and obtain received data (RA, RB) of each modulated signal. This allows received data RA, RB with a good error rate characteristic to be obtained with a relatively small number of calculations without reducing data transmission efficiency.

Abstract: A communication apparatus is provided in which only a terminal having a specific positional relationship can perform communication through a relatively simple arrangement. When initial setting is performed or communication is started, a timing calculator calculates a time difference corresponding to the difference between a path from a first antenna to a terminal and a path from a second antenna to the terminal, based on a transmission signal from the first antenna and a reflection signal provided by having the transmission signal reflected from the second antenna or a communication partner, i.e. the terminal, and returned back to the first antenna. Based on the time difference thus calculated, the timing calculator outputs a signal for regulating the transmission timing of transmission data from the first antenna to a variable delay unit.

Abstract: By compensating for a detection result of the detector in feedback control of output power of the power amplifier, the polar modulation transmission apparatus is able to realize accurate transmission power control. Polar modulation transmission apparatus 100 has detector 106 that detects output power of power amplifier 103, PAPR calculating section 131 that calculates the PAPR of the spread modulated signal, compensation value generating section 134 that outputs a compensation value corresponding to the calculated PAPR and an arithmetic operator that performs an arithmetic operation using the compensation value and a detection result obtained by detector 106. By this means, it is possible to compensate for the sensitivity of detector 106 (measurement sensitivity) that changes depending on the ? parameter and mode and make the sensitivity of detector 106 (measurement sensitivity) virtually constant.

Abstract: It is possible to demodulate a plurality of modulated signals transmitted from a plurality of antennas by using a comparatively small-size circuit with a preferable error ratio characteristic. Partial bit judgment units (509, 512) demodulates partial bits of the 64QAM-modulated signal by modifying which of the bits in the 6-bit strings constituting a symbol is to be demodulated depending on in which region of the IQ plane the reception signal point exists. This improves the partial bit error characteristic judged by the partial bit judgment units (509, 512), which in turn improves reliability of the reduced candidate signal point for use by a likelihood detection unit (518). As a result, it is possible to improve the error ratio characteristic of the final reception digital signals (322, 323).

Abstract: It is an object of the present invention to provide a sampling mixer and a receiver, capable of optimizing a sampling rate of an output signal in response to a fractional band of a modulation band with respect to an RF frequency of the received signal. A sampling mixer of the present invention, includes a history capacitor 6 for integrating a received signal that is converted in terms of current in a continuous time, rotation capacitors 7 to 14 for repeating an integration and a discharge of an input signal, a digital controller 104 for controlling integration periods of the rotation capacitors 7 to 14, and a controlling portion 105 for controlling discharges of the rotation capacitors 7 to 14, wherein the number of the rotation capacitors 7 to 14 connected at a time to a buffer capacitor 15 is switched in answer to a fractional band of the modulation band with respect to a RF frequency.

Abstract: The present invention has an object to provide a sampling filter apparatus and a wireless communication apparatus, which are capable of changing a filter characteristic without employing complex waveforms as control signals, and also, capable of performing filtering process operations without performing a decimation, while utilizing a wide frequency space. A sampling filter apparatus 100 includes a controller 140, a plurality of integrators 150 to 154, a plurality of switches 130, 160 to 164, 170 to 174, 180 to 184, and a plurality of voltage/current converters 120 to 123. An inputted current is stored in four pieces of integrators selected among the plurality of integrators 150 to 154 by one clock, and electric charges which have been stored from four preceding clocks up to one preceding clock are added to each other so as to output the added electric charges from the remaining one integrator.

Abstract: An input digital signal is periodically and alternately subjected to first modulation and second modulation, being thereby converted into a pair of a baseband I signal and a baseband Q signal. The first modulation and the second modulation are different from each other. The pair of the baseband I signal and the baseband Q signal are outputted. The first modulation may be at least 8-signal-point modulation while the second modulation may be phase shift keying.