Abstract: Embodiments of the present invention provide a method and apparatus for controlling update of digital pre-distortion (DPD) coefficient. The apparatus is applicable to a digital power control system, wherein the apparatus comprises: an update controlling unit configured to determine a group of fully-trained DPD coefficients among a plurality of DPD coefficients; and a DPD coefficient generating unit configured to update adaptively the group of fully-trained DPD coefficients according to the result of judgment of the update controlling unit.

Abstract: This invention relates to an apparatus for and a method of controlling a predistorter, and a method of detecting power control state. The method of controlling a predistorter, which is for predistorting a signal input into a power amplifier, comprises storing predistortion coefficients used by the predistorter; acquiring indices each indicative of an output power of the power amplifier; detecting, based on the indices acquired in the acquiring, whether the power amplifier is in a state of undergoing power control; and supplying the stored predistortion coefficients to the predistorter when it is detected that the power amplifier is in the state of undergoing power control, or supplying, when it is detected that the power amplifier is not in the state of undergoing power control, to the predistorter predistortion coefficients calculated by a unit that performs predistortion coefficient adaptive updating operation.

Abstract: An embodiment of the invention discloses a power amplification device and method and a method for acquiring a power adjusting coefficient. The power amplification device according to one embodiment of the invention includes: a power control module configured to perform power adjusting on an input signal; a power amplification module configured to perform power amplification on the signal subjected to the power adjusting by the power control module; and a pre-distortion module configured to compensate for nonlinear characteristic of the power amplification module; wherein, said power control module is coupled between said pre-distortion module and said power amplification module in series; alternatively, said pre-distortion module is coupled between said power control module and said power amplification module in series. With the embodiment of the invention, a transmitter can be provided with a spectrum including a low side lobe even upon startup.

Abstract: A communication device is used by a mobile station to perform wireless communication with another mobile station. The communication device includes a processor configured to set a transmission resource according to a present position of the mobile station, the transmission resource being set based on transmission resource association information including different transmission resources assigned to plural assignment areas provided at different positions along a road through which the mobile station passes; and a transmitter configured to transmit data with the use of the transmission resource that has been set.

Abstract: For transmitting a common channel signal with characteristics with an approximated non-directivity, the common channel signal for all users is divided into sub-channel signals, corresponding to a number of antenna elements composing an array antenna, to be concurrently transmitted with non-directivity by using each antenna element. Individual channel signals, for each user, following the common channel signal with a desired directivity by using the antenna elements. Each sub-channel signal can be made a sub-channel signal obtained by dividing all sub-channel components composing the common channel signal for each sub-channel component by a predetermined number or dividing them depending on a receiving quality of each antenna element.

Abstract: A receiver receives a reception signal subjected to orthogonal frequency division multiplexing modulation or orthogonal frequency division multiple access modulation. The receiver has: an array antenna for receiving the reception signal; adaptive equalizers provided in each of the plurality of antennas, and reducing advanced or delayed waves having a delay time to a main wave in the reception signal; a spatial diversity combining portion which multiplies output signals of the adaptive equalizers by a weighting coefficient and adds the multiplied signals; a weight control portion generating the weighting coefficient; and an equalizer setting unit which estimates an arrival angle and a delay time for each path of the reception signal, and based on the estimation, decides an interference wave to be eliminated by the adaptive equalizers among interference waves, and sets in the adaptive equalizers the delay time of the decided interference wave.

Abstract: A base station assigns a subcarrier for downlink communications under Orthogonal Frequency Division Multiple Access. Before downlink communications with a mobile station, based on carrier sensing by the mobile station, the base station detects information concerning an available subcarrier from downlink signals using a modulating unit. The information concerning the available subcarrier is stored in a downlink-information sharing unit and is shared among the base station and the adjacent base stations. A downlink subcarrier setting unit sets the available subcarrier for downlink communications.

Abstract: A communication device is used by a mobile station to perform wireless communication with another mobile station. The communication device includes a processor configured to set a transmission resource according to a present position of the mobile station, the transmission resource being set based on transmission resource association information including different transmission resources assigned to plural assignment areas provided at different positions along a road through which the mobile station passes; and a transmitter configured to transmit data with the use of the transmission resource that has been set.

Abstract: This invention relates to an apparatus for and a method of controlling a predistorter, and a method of detecting power control state. The method of controlling a predistorter, which is for predistorting a signal input into a power amplifier, comprises storing predistortion coefficients used by the predistorter; acquiring indices each indicative of an output power of the power amplifier; detecting, based on the indices acquired in the acquiring, whether the power amplifier is in a state of undergoing power control; and supplying the stored predistortion coefficients to the predistorter when it is detected that the power amplifier is in the state of undergoing power control, or supplying, when it is detected that the power amplifier is not in the state of undergoing power control, to the predistorter predistortion coefficients calculated by a unit that performs predistortion coefficient adaptive updating operation.

Abstract: An embodiment of the invention discloses a power amplification device and method and a method for acquiring a power adjusting coefficient. The power amplification device according to one embodiment of the invention includes: a power control module configured to perform power adjusting on an input signal; a power amplification module configured to perform power amplification on the signal subjected to the power adjusting by the power control module; and a pre-distortion module configured to compensate for nonlinear characteristic of the power amplification module; wherein, said power control module is coupled between said pre-distortion module and said power amplification module in series; alternatively, said pre-distortion module is coupled between said power control module and said power amplification module in series. With the embodiment of the invention, a transmitter can be provided with a spectrum including a low side lobe even upon startup.

Abstract: A receiver receives a reception signal subjected to orthogonal frequency division multiplexing modulation or orthogonal frequency division multiple access modulation. The receiver has: an array antenna for receiving the reception signal; adaptive equalizers provided in each of the plurality of antennas, and reducing advanced or delayed waves having a delay time to a main wave in the reception signal; a spatial diversity combining portion which multiplies output signals of the adaptive equalizers by a weighting coefficient and adds the multiplied signals; a weight control portion generating the weighting coefficient; and an equalizer setting unit which estimates an arrival angle and a delay time for each path of the reception signal, and based on the estimation, decides an interference wave to be eliminated by the adaptive equalizers among interference waves, and sets in the adaptive equalizers the delay time of the decided interference wave.

Abstract: A radio communication system including a first terminal apparatus group for performing a reception by using a first radio resource and a transmission by using a second radio resource; and a second terminal apparatus group for performing the reception by using the second radio resource and the transmission by using the first radio resource, and a directly radio communication is performed, the system including: a first terminal which belongs to the first terminal apparatus group and transmits allocation request of transmission band in the second radio resource by using the second radio resource; and a second terminal which belongs to the second terminal apparatus group, receives the allocation request transmitted from the first terminal, and transmits information indicating allocation of the transmission band for the first terminal, wherein the first terminal transmits data by using the allocated transmission band in the second radio resource.

Abstract: A wireless communication system including: a first terminal device; and a second terminal device, wherein wireless communication is performed between the first and second terminal devices, the first and second terminal devices each include a processing unit performs wireless communication with the second and first terminal device respectively, using a wireless resource allocated within a first or second zone in accordance with a distance between the first and second terminal devices, and a wireless frame including a frequency domain and a time domain is divided into at least the first and second zones in the frequency domain or the time domain.

Abstract: A demodulation circuit can perform a capturing operation although a frequency error is large. A phase comparator out puts a predetermined value other than 0 as a determination result of a phase error when a phase error of a carrier wave is large and a signal point is located at a predetermined position. A loop filter outputs a negative minimum value to an integrator when an integrated value of a determination result reaches a positive maximum value of a limiter. Thus, when a phase error is large, a value changing from a negative minimum value to a positive maximum value is output from the loop filter, thereby realizing a broad synchronous capture range.

Abstract: For transmitting a common channel signal with characteristics with an approximated non-directivity, the common channel signal for all users is divided into sub-channel signals, corresponding to a number of antenna elements composing an array antenna, to be concurrently transmitted with non-directivity by using each antenna element. Individual channel signals, for each user, following the common channel signal with a desired directivity by using the antenna elements. Each sub-channel signal can be made a sub-channel signal obtained by dividing all sub-channel components composing the common channel signal for each sub-channel component by a predetermined number or dividing them depending on a receiving quality of each antenna element.

Abstract: A radio communication apparatus includes a vertical polarization antenna, a horizontal polarization antenna, a receiving-side phase rotation unit configured to rotate a phase of a signal received by the vertical polarization antenna and a phase of a signal received by the horizontal polarization antenna, and a maximum power detector configured to determine a phase associated with a maximum power of the two received signals and to provide the receiving-side phase rotation unit with the phase associated with the maximum power. The receiving-side phase rotation unit rotates the phase of the two received signals by the phase associated with the maximum power.

Abstract: A radio communication apparatus includes a mapping unit configured to map data to a burst data transmission region corresponding to radio resources; and a transmitter configured to transmit the data mapped to the burst data transmission region, where a reference signal used for canceling an interference wave is mapped to the data transmission region.

Abstract: An apparatus for communications includes, a front processor for outputting a digital formatted base band signal with quadrature demodulating a modulated signal; an interpolation processor for interpolating to adjust a phase error in accordance with sampling timing on the basis of the base band signal outputted from the front processor and for creating and outputting a base band signal synchronized with the sampling timing; and a back processor for wave-shaping the base band signal outputted from the interpolation processor and for outputting. And the apparatus changes tap coefficients which are supplied to an FIR filter in the interpolation processor on the basis of the modulated signal inputted therein, and can appropriately control the bandwidth characteristic of interpolators.

Abstract: An array antenna directivity control apparatus for use in tracking a target updates a weighting coefficient based on an error between antenna signals of multiple antennas and a known reference signal, and corrects an amount of updating for each of the weighting coefficients. The updating is performed based on predict error information predicted based on past errors. As a result, it is possible to adjust a weighting coefficient based on a prediction of the next position of a target. Thus, it is possible to track a target which is being moving at high speed with a small amount of calculation.

Abstract: In an OFDM transmitter apparatus for transmitting transmit signals, which are output from first and second OFDM transmit circuits, utilizing two mutually orthogonal polarized waves, a single carrier wave generator is provided in common for the OFDM transmit circuits, and a frequency converter in each OFDM transmit circuit multiplies a baseband signal by a common carrier wave, which is output from the carrier wave generator, to convert the baseband signal to a radio signal.