Abstract: Filtering part 50 performs filtering by converting a received signal sampled using a predetermined number of over-samples to an over-sample number small enough to avoid frequency-domain foldover noise generation. Transmission channel estimation part 60 performs path timing detection by converting the received signal sampled using a predetermined number of over-samples to an over-sample number large enough to obtain sufficient timing resolution, converts transmission channel responses for each path timing to the frequency domain, and calculates transmission channel estimates corresponding to the subcarriers of the received signal in the frequency domain. Weight calculation part 6 receives the frequency-domain channel estimates outputted from transmission channel estimation part 60 and calculates the weights of the equalizing filter used in filtering part 50.

Abstract: An equalizer calculates an equalization weight using a transmission channel response vector that arranges transmission channel estimation at the detection path timing and at the neighbor path timings thereof. The equalizer realizes excellent equalization characteristics by generating a transmission channel response vector that will not be affected by MPI by use of a multipath interference canceller (MPIC) to calculate the equalization weight.

Abstract: An adaptive antenna receiver whose follow-up performance is improved with respect to the angle change of the arrival direction of a desired signal. An antenna weight adaptive update section (11-1) adaptively updates the antenna weight according to a signals received by each antenna element and an error signal obtained from a desired signal corrected based on transmission channel estimation. An antenna weight direction constraint section (12-1) performs the constraint process for the antenna weight obtained by the antenna weight adaptive update section (11-1) to maintain the beam gain constant in the arrival direction of the desired signal. A beamformer (2-1) receives the desired signal through an array antenna using the antenna weight which has undergone the constraint process performed by the antenna weight direction constraint section (12-1).

Abstract: A receiver uses a transmission channel matrix to obtain a superior signal separation characteristic regardless of differences in levels of multipath signals. A multipath linear combining unit performs linear combining of the multipaths in received signals of the reception antennas by means of the transmission channel matrix between the plurality of transmission antennas and the plurality of reception antennas. A maximum likelihood detector compares signals in which multipaths have been combined by the multipath linear combining unit with reception replicas that have been found using the transmission channel matrix to estimate the transmitted signals of each of the transmission antennas.

Abstract: In an arrangement for receiving CDMA signals, insertion of guard intervals is rendered unnecessary and transmission efficiency loss is suppressed, along with greatly reducing the computational burden of weight calculations. Impulse responses of a transmission channel are obtained by time-domain signal processing, the impulse responses are Fourier transformed and converted into frequency domain signals, equalizing filter weights are calculated using the frequency domain impulse responses, the calculated frequency domain weights are converted to time domain weights using an inverse Fourier transform, the received signals are filtered using time-domain signal processing, and data signals are demodulated by despreading the equalized signals.

Abstract: An adaptive antenna reception apparatus includes a multi-beam former (1) provided in common to users, to convert antenna-corresponding spread signals received by antennas of an array antenna into beam-corresponding spread signals. A receiving and demodulating section (2) is provided for one of the users, generates beam-corresponding correlation signals at a path timing from the beam-corresponding spread signals, and generates path signals by weighting the beam-corresponding correlation signals with adaptive weights which are updated adaptively, and produces a demodulation signal for the one user by combining the path signals.

Abstract: A MIMO receiver, a MIMO reception method and a wireless communication system capable of accurate MMSE control even when each transmit antenna uses a different chip power ratio in MIMO filter reception. A correction coefficient calculator receives as input the chip power ratio of each transmit antenna, and estimates such pilot power that renders the chip power ratio of each transmit antenna equal to that of a reference transmit antenna. Thereby, the correction coefficient calculator calculates a correction coefficient ?m to correct the actual pilot power of each transmit antenna. A weight calculator receives as input transmission channel impulse responses transferred into frequency domain by FFT sections, chip noise power estimated by a chip noise estimation section, and the correction coefficient ?m obtained by the correction coefficient calculator. The weight calculator calculates filter weights according to the minimum mean square error (MMSE) criterion.

Abstract: A radio transmitter-receiver wherein a pilot symbol is used in the transmitter that has undergone M-chip spreading on the frequency axis and N-chip spreading on the time axis by a spreading code of M×N chip length (where M and N are any integers equal to or greater than 2), and in the receiver, a spreading code that is not used in spreading said pilot signal is used as a despreading code to despread a received signal and then estimate noise and interference power. The spreading code that is used to spread the pilot symbol and the despreading code that is used in despreading are assigned so as to be orthogonal even if only in N chips on the time axis.

Abstract: In soft hand over in a code division multi access mobile radio communication system, interference in a down link caused by transmission from a plurality of base stations for one mobile station, can be restricted. Control of transmission power is performed according to command from the mobile station only in the base station serving as a primary base station which has minimum propagation loss with the mobile station during soft hand over, and the base stations other than the primary base station perform transmission with restricting output. In comparison with the transmission power control performed by the conventional plural base station transmission, interference for the peripheral mobile station can be reduced to achieve higher down link capacity.

Abstract: An SINR estimating unit of a receiver apparatus measures first and second demodulated signals to calculate SINR (ratio of signal power to sum of interference power and noise power) for each signal sequence. A transmission parameter deciding unit decides, based on the SINR, a transmission parameter used by a transmitter apparatus for controlling the transmission for each signal sequence, and then feeds the decided transmission parameter back to the transmitter apparatus. First and second mapping units of the transmitter apparatus controls, based on the transmission parameters as fed back, the modulation level for each signal sequence.

Abstract: A transmitter of a base station includes a data serial-to-parallel converter, M modulators, M beam formers, and transmission antennas. The data serial-to-parallel converter converts transmission data into M sequences. Each modulator modulates the transmission data. Each beam former weights the modulation signal to form directional beams. The transmission antennas narrow the beams and transmit the modulation signals in parallel (MIMO transmission). In a mobile station, a receiver has reception antennas for receiving data transmitted in parallel and an MIMO demodulator for demodulating the data.

Abstract: In soft hand over in a code division multi access mobile radio communication system, interference in a down link caused by transmission from a plurality of base stations for one mobile station, can be restricted. Control of transmission power is performed according to command from the mobile station only in the base station serving as a primary base station which has minimum propagation loss with the mobile station during soft hand over, and the base stations other than the primary base station perform transmission with restricting output. In comparison with the transmission power control performed by the conventional plural base station transmission, interference for the peripheral mobile station can be reduced to achieve higher down link capacity.

Abstract: There is provided an adaptive transceiver device which estimates a path arrival direction of a desired wave signal by using a reception antenna weight of a k-th user adaptive reception unit using a control method based on the minimum mean square error (MMSE) standards and which generates a transmission antenna weight on the basis of the path arrival direction. The adaptive transceiver device is characterized in that in reception, a directivity pattern for suppressing interference caused by another user or a multi-path is formed, an arrival direction of a path is estimated from the reception antenna weight, and a transmission direction is predicted from the estimated arrival direction to generate a transmission antenna weight, and in transmission, a directivity pattern for decreasing interference to another user is formed and transmitted.

Abstract: A mobile communication system capable of improving the system throughput. A base station (1) divides one cell into three sectors. A common pilot channel is transmitted to a plurality of mobile stations in the sectors by beams (101-103) whose directivity is controlled by an adaptive antenna for each of the sectors. On the other hand, when a mobile station (2) communicates data with the base station (1), the base station transmits a data channel and an individual control channel to the mobile station (2) by using a beam (201) whose directivity is controlled individually. The mobile station (2) switches between the common pilot channel and the individual control channel from the base station (1) for estimating the communication path quality.

Abstract: In an adaptive array antenna receiving apparatus, signal to interference ratio (SIR) measuring units are provided in signal processing units, respectively. The SIR measuring units measure signal to interference ratios of existing fingers to supply the measured results for an antenna weight succession processing unit. The antenna weight succession processing unit selects one of the existing fingers on the basis of the measured results. The antenna weight succession processing unit extracts antenna weights from one of the signal processing units that corresponds to the selected finger. The antenna weight succession processing unit supplies the extracted antenna weights to a newly assigned finger or one of the existing fingers that path timing is greatly changed.

Abstract: An array antenna reception apparatus includes an array antenna, K adaptive receivers, and demodulated signal synthesizer. The array antenna has M (M is an integer of 1 or more) antenna elements linearly laid out on each side (sector) of a polygon having K (K is an integer of 3 or more) sides. Each adaptive receiver receives reception signals from the M antenna elements for a corresponding sector, independently forms a directional pattern having a gain in a desired signal direction for the sector, receives a desired signal, and suppresses an interference signal. The demodulated signal synthesizer receives K demodulated signals as outputs from the K adaptive receivers, weights and synthesizes the signals, and outputs a demodulated signal for a user.

Abstract: A cellular type mobile communication system comprising a plurality of cells, a plurality of base stations disposed in the respective cells, and a mobile station located in the cells. On reception of a control command for a transmission power from the mobile station, each base station increases or decreases the transmission power in response to the control command. In addition, each base station renews the transmission power so that the transmission power after increased or decreased approaches a predetermined reference power.

Abstract: A CDMA adaptive antenna receiving apparatus is provided with plural receivers of which each is for receiving one or more of desired signal components incoming at the same time. Each of the plural receivers includes plural adaptive receiving units for updating sequentially a directivity in accordance with one desired signal component. The plural adaptive receiving units which are included in the same receiver employ a symbol decision error of the same receiver in common. Each receiver further includes a means for detecting the incoming directions of the plural desired signal components and a means for controlling directivities of the plural adaptive receiving units in accordance with the incoming directions of the plural desired signal components and directivities of the plural adaptive receiving units.

Abstract: A transmitter of a base station includes a data serial-to-parallel converter, M modulators, M beam formers, and transmission antennas. The data serial-to-parallel converter converts transmission data into M sequences. Each modulator modulates the transmission data. Each beam former weights the modulation signal to form directional beams. The transmission antennas narrow the beams and transmit the modulation signals in parallel (MIMO transmission). In a mobile station, a receiver has reception antennas for receiving data transmitted in parallel and an MIMO demodulator for demodulating the data.

Abstract: In an adaptive antenna receiving apparatus, a plurality of correlations between adjacent antennas are detected for each path, a fixed beam unique to each path arrival direction of the desired wave is formed on the basis of a vector generated by averaging the detected correlations, and each path is received and combined, or a plurality of correlations between adjacent antennas are detected for each signal sequence despread with a plurality of chip timings, a fixed beam unique to the arrival direction of each signal sequence is formed on the basis of a vector generated by averaging the detected correlations, and a path timing is detected on the basis of a delay profile generated from an output of each signal sequence, or a plurality of correlations between adjacent antennas are detected for each signal sequence despread with a plurality of chip timings, a fixed beam unique to the arrival direction of each signal sequence is formed on the basis of a vector generated by averaging the detected correlations, a path