Abstract: In a wireless communication system, in which a frame comprising data and control information necessary for reception processing of the data is transmitted from a transmitter, and in which, when a reception failure is notified by a receiver, the frame that failed to be received is retransmitted, the control information is classified into first control information that can be different for a new frame transmission and a repeat frame transmission and second control information that is the same for the new frame transmission and the repeat frame transmission, information indicating whether or not the receiver has correctly received the control information and data is acquired, and when the control information has been correctly received, control is conducted so that the second control information is not transmitted during the repeat frame transmission.

Abstract: In a multiple-input multiple-output transmission system (MIMO system), a receive station detects whether or not there is an error in each data stream, estimates the state of the propagation path of each transmit antenna and reports, to the transmitting side, re-transmission necessary/unnecessary information, for every data stream, created based upon whether or not there is an error, and the state of the propagation path of each transmit antenna. A transmit station decides a transmit antenna that transmits a data stream requiring re-transmission, based upon the reported state of the propagation path of each transmit antenna, and re-transmits the data stream requiring re-transmission from the transmit antenna decided.

Abstract: A radio communication system in which a transmission station performs window function processing on a transmission symbol to which cyclic prefixes have been attached for each specified number of samples, then transmits the signal, and a receiving station extracts and demodulates effective signal portions from the received signal, wherein the transmission station uses a control channel to notify the receiving station of window width Nwin of the window function; the receiving station adjusts the extraction position of the received signal based on the window width notified from the transmission station; and the receiving station uses the extracted received signal to execute demodulation processing of the transmission symbol.

Abstract: When performing communication with a mobile station using MIMO-OFDM communication, a base station uses multiple input multiple output (MIMO) communication, which is multiple data stream transmission, to transmit data and pilot signals in a case where the communication environment of the mobile station is good, or uses single input multiple output (SIMO) communication, which is single data stream transmission, in a case where the communication environment of the mobile station is poor. When performing that SIMO communication, the base station performs control so that pilot signals from a specified cell that are used in channel estimation in single data stream transmission and pilot signals from adjacent cells that are used in channel estimation in single data stream transmission do not overlap in the frequency direction and/or time axis direction.

Abstract: An information communication method, which is executed on a transmitting side, is provided. The method comprises a first step of transmitting communication data to a receiving side; and a second step of retransmitting the communication data to the receiving side without waiting for an arrival of a negative acknowledgement signal of the communication data, which arrives from the receiving side, or an elapse of a predetermined acknowledgement wait time.

Abstract: In multicarrier transmission for multiplying transmit data individually by each code constituting orthogonal codes and transmitting each result of multiplication by a prescribed subcarrier, a plurality of different subcarriers are assigned exclusively to each user and each user performs multicarrier transmission of the transmit data by the subcarriers assigned. Further, a base station assigns a plurality of different subcarriers to each user exclusively, applies beam-forming processing on a per-user basis and performs multicarrier transmission of transmit data to each user by the subcarriers assigned.

Abstract: A system performing communication by using a plurality of antennas is presumed to transmit a frame from an antenna 1 by structuring slots 1 and 2 in the frame, and another frame from an antenna 2 by structuring slots 3 and 4 in the frame. A reception side examines a presence or absence of an error for each slot. Assuming that there is an error in the slots 1 and 4, the reception side notifies the transmission side of information on the existence of errors in the slots 1 and 4. The transmission side embeds the slots 1 and 4 in a frame made up of two slots and retransmits the slots 1 and 4 respectively from the antennas 1 and 2.

Abstract: A method of transmitting pilot signals for channel compensation in a mobile communication system based on DFT-spread-OFDM is disclosed. In the disclosed method, a first pilot signal and a second pilot signal are time-division multiplexed together with a data signal of a user into a time-division multiplexed signal which data signal is assigned a certain bandwidth; the time-division multiplexed signal is frequency-division multiplexed together with time-division multiplexed signals of other users when wirelessly transmitted; and the first pilot signal is assigned a bandwidth larger than the bandwidth of the data signal and the second pilot signal is assigned a bandwidth smaller than the bandwidth of the data signal.

Abstract: A receiving station repeatedly performs decoding processing of data in a decoding processing portion, performs error detection of the decoding results, and transmits to a transmitting station an error detection result (ACK/NACK) for decoding results for a preset number of executions, and moreover issues a request to the transmitting station to modify the data transmission interval based on the data reception characteristic. The transmitting station transmits data at transmission intervals according to the transmission interval modification requests sent from the receiving station. The receiving station selectively inputs to the decoding processing portion the data received from the transmitting station and the previous decoding result data.

Abstract: A radio transmission apparatus includes: a guard interval insertion unit that inserts a guard interval in every data block of a transmission data signal; a waveform shaping unit that performs a signal attenuation processing in a time period that includes a boundary of a signal block in which the guard interval has been inserted; and a controller that controls an insertion period of the guard interval by the guard interval insertion unit such that the data block is located in a time period exclusive of the time period which is a signal attenuation period by the waveform shaping unit. By this, in an environment where a signal to which a window function (band limitation) is applied may be received, while the guard intervals are effectively utilized, degradation of reception characteristics due to influence of the band limitation is prevented.

Abstract: A pilot signal is transmitted with a predetermined frequency band and a data signal is transmitted with a partial band of the frequency band, and the pilot signal and the data signal to be transmitted with at least the partial band, are controlled its waveform to have the same waveforms in a frequency domain. Thus, in the case of controlling waveforms of the pilot signal and the data signal which have different occupied bands, it is possible to, in a portion of the occupied band for the data signal, avoid the mapping of a low-quality pilot signal or the like, enhance the data signal demodulation capability and improve the data signal reception characteristic while suppressing PAPR.

Abstract: The present invention relates to a wireless communication device and a wireless communication method that improve a throughput without increasing an overhead of a wireless frame. The wireless communication device performing communications by using a wireless frame containing a control channel and a data channel, for improving the throughput without increasing the overhead of the wireless frame, comprises a structuring unit allocating, as second control information, part of control information used for communication control to the data channel with respect to a transmitted wireless frame to be transmitted to one other wireless communication device.

Abstract: In a wireless communication system, in which a frame comprising data and control information necessary for reception processing of the data is transmitted from a transmitter, and in which, when a reception failure is notified by a receiver, the frame that failed to be received is retransmitted, the control information is classified into first control information that can be different for a new frame transmission and a repeat frame transmission and second control information that is the same for the new frame transmission and the repeat frame transmission, information indicating whether or not the receiver has correctly received the control information and data is acquired, and when the control information has been correctly received, control is conducted so that the second control information is not transmitted during the repeat frame transmission.

Abstract: In a searcher of a CDMA receiver comprising an array antenna, a voltage profile generation portion performs correlation computations of received signals for each antenna element and generates received signal voltage profiles; a phase difference estimation portion uses sample data from each voltage profile at the same time to perform correlation calculations among antenna elements and estimates the phase difference among antenna elements at the above time, and similarly estimates the phase differences among antenna elements at each time. An in-phase synthesis portion uses the phase difference estimate at a prescribed time to coordinate the phases of voltage profiles for each antenna element at the above time and performs synthesis, and similarly coordinates the phases of each antenna element voltage profile at other times and performs synthesis; and, a path detection portion detects the path timing of multiple paths based on the synthesized profile obtained by the in-phase synthesis portion.

Abstract: Channel estimation values of pilot symbols for channel compensation of data symbols in an OFDM receiver can be used, even in cases where FFT extract position differs for each frame. The OFDM receiver is characterized in having a circuit which calculates the amount of phase rotation that is generated by the difference in timing at which the individual symbols are extract as objects of a fast Fourier transform when the fast Fourier transform processing is performed by a fast Fourier transform circuit, and further a circuit which corrects the amount of phase rotation for the channel estimation value determined by a channel estimating circuit.

Abstract: In a multiple-input multiple-output transmission system (MIMO system), a receive station detects whether or not there is an error in each data stream, estimates the state of the propagation path of each transmit antenna and reports, to the transmitting side, re-transmission necessary/unnecessary information, for every data stream, created based upon whether or not there is an error, and the state of the propagation path of each transmit antenna. A transmit station decides a transmit antenna that transmits a data stream requiring re-transmission, based upon the reported state of the propagation path of each transmit antenna, and re-transmits the data stream requiring re-transmission from the transmit antenna decided.

Abstract: A delay profile estimation apparatus and a correlating unit to obtain delay profile with suppressed noise are disclosed. The delay profile estimation apparatus includes a receiving unit to receive a communication signal (received signal), a conversion unit to inverse-Fourier-transform a known pilot signal that consists of N samples, a correlating unit to obtain a correlation value between the inverse-Fourier-transformed known pilot signal and the received signal, the correlating unit being connected to the receiving unit and the conversion unit, and a delay profile generating unit for generating a delay profile of the received signal based on the correlation value. The correlating unit cyclically shifts N samples of the received signal, or the N samples of the known pilot signal when calculating the correlation value corresponding to a phase difference between the inverse-Fourier-transformed known pilot signal and the received signal.

Abstract: A delay profile estimation apparatus and a correlating unit to obtain delay profile with suppressed noise are disclosed. The delay profile estimation apparatus includes a receiving unit to receive a communication signal (received signal), a conversion unit to inverse-Fourier-transform a known pilot signal that consists of N samples, a correlating unit to obtain a correlation value between the inverse-Fourier-transformed known pilot signal and the received signal, the correlating unit being connected to the receiving unit and the conversion unit, and a delay profile generating unit for generating a delay profile of the received signal based on the correlation value. The correlating unit cyclically shifts N samples of the received signal, or the N samples of the known pilot signal when calculating the correlation value corresponding to a phase difference between the inverse-Fourier-transformed known pilot signal and the received signal.

Abstract: Provided is a mobile cellular communication system or, more particularly, a transmission diversity communication system in which when the number of transmitting antennas is increased, antennas can be calibrated readily and efficiently with power saved without degradation of the characteristic concerning fading. The transmission diversity communication system is a closed-loop transmission diversity communication system. In the transmission diversity communication system, a base station transmits common pilot signals via a plurality of antennas, and a mobile station receives the common pilot signals. The mobile station transmits feedback signals, which are produced through analysis of the common pilot signals, to the base station. The base station controls a downward transmission signal on the basis of the pieces of feedback information. Herein, the plurality of antennas is divided into a plurality of groups. The common pilot signal is transmitted via a reference antenna included in each of the groups.

Abstract: Disclosed is a feedback control method in closed-loop transmit diversity in which feedback information representing amounts of amplitude and phase control is transmitted from a mobile station to a radio base station. The mobile station receives downlink pilot signals, which are transmitted by a handover-destination base station, during handover control, calculates feedback information, which represents amounts of amplitude and phase and phase control transmitted to the handover-destination base station, beforehand based upon the pilot signals received, and transmits the feedback information to the handover-destination base station before completion of base-station changeover by handover.