Abstract: To provide a reception method and a reception device in which a base station can correct a frequency offset contained in a reception signal and realize an excellent reception characteristic by using simple reception mechanism of a frequency region in a radio system of the frequency division multiplex type.

Abstract: A receiving apparatus is provided in which a single carrier signal is received by a plurality of receiving antennas, and multipath equalization and other cell interference suppression are carried out in a frequency domain at a same time. A plurality of antennas 1-1 to 1-N receives the single carrier signal. The DFT sections 3-1 to 3-N converts the reception signals into frequency domain signals. A channel estimating section 5 estimates a channel gain of a desired user signal by using pilot reception signals. An interference correlation matrix estimating section 6 estimates an interference correlation matrix from the pilot reception signals and a channel estimation value. A weight, calculating section. A weight calculating section 7 receives the channel estimates and the interference correlation matrix and calculates equalization weights. An equalising section 8 performs multipath equalization and other cell interference suppression to the desired user signal in a frequency domain.

Abstract: A multi-user receiving apparatus is provided for achieving a reduction in the amount of processing for single-carrier FDMA signals and an improvement in reception characteristics. A DFT unit converts single-carrier FDMA received signals of all users to signals in a frequency domain commonly. A demapping unit selects part of sub-carriers for each user from sub-carriers supplied from the DFT unit. A reception filter separates a user signal and suppresses noise. A demodulator demodulates the user signal, and detects a timing thereof.

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: In a MIMO receiving apparatus, signals of single carriers transmitted from a plurality of transmission antennas are received by a plurality of reception antennas (1-1 through 1-N) and then separated according to frequency domain. In this MIMO receiving apparatus, interference replicas of the antennas are eliminated from received signals (by subtractor 54) before equalizing the two-dimensional frequency domain, and distortion free signal replicas are added (by demodulating part 55) to the signals from which the interference replicas of the antennas have been eliminated after equalizing the two-dimensional frequency domain.

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 reception device is disclosed in which a directional beam having excellent reception characteristics can be quickly and easily obtained from the start by selecting an initial beam direction of signal processors that are to begin determination of weight that uses time averaging based on the reception quality and the arrival direction in which the reliability is high for an incoming wave that is received in each signal processor in which sufficient averaging time has been secured. An arrival direction detection unit detects the arrival direction of an incoming wave that is received in each signal processor from weight that is determined by each signal processor in which at least a prescribed time interval has been secured for the averaging time for finding a time average.

Abstract: A priority computation process computes a priority of each user for each RB (Resource Brock) using a reception SINR. A maximum priority user selection/RB allocation process selects a user with the maximum priority for an unallocated RB and allocates the RB to the user. A frequency axis/space axis unallocated RB presence determination process proceeds to scheduling for a next user if there is an unallocated RB on the frequency or space axis. A projected channel vector update process updates a projected channel vector of an unselected user by GS orthogonalization. An orthogonal coefficient computation process computes an orthogonal coefficient. A corrected SINR computation process computes a corrected SINR. A next MIMO layer priority computation process computes priorities of unselected users for a corresponding RB in the next multiple MIMO layer. The priorities of the unselected users are used in the next user scheduling processing.

Abstract: A multibeam transmitting/receiving apparatus is provided that is capable of increasing the accuracy of a direction in which a transmission beam is to be transmitted, with a simple arrangement. Signal power measuring units (8-1 through 8-L) of signal processing means (40-1 through 40-L) measure reception signal power levels averaged over a given time, using outputs from reception beam formers (5-1 through 5-L), and indicate the measured reception signal power levels to transmission antenna weight generator (30). Transmission antenna weight generator (30) generates transmission antenna weights, which has been weighted by a reception signal level, from a transmission antenna weight corresponding to reception signal power level P1 and a beam number B1 of a finger having a maximum reception signal power level, and a transmission antenna weight corresponding to reception signal power level P2 and a beam number B2 of a finger having the same path timing as the finger having the maximum reception signal power level.

Abstract: Provided are a channel estimation device and an equalization device capable of achieving high channel estimation accuracy with less amount of calculation processing. The equalization device includes: a channel estimation section including a ZF calculation/clipping processing section and correlation processing section; a weight calculation section; and an equalization filter. The ZF calculation/clipping processing section uses a signal obtained by converting a pilot code into a frequency domain to calculate a pilot reference signal according to a Zero Forcing (ZF) method and clips the gain of the calculated pilot reference signal to a predetermined value to generate a clipped pilot reference signal. The correlation processing section performs correlation between a pilot reception signal in the frequency domain and clipped pilot reference signal to estimate channel characteristics of the frequency domain.

Abstract: A correction coefficient calculating section 20 calculates a correction coefficient ? so as to obtain a noise power equivalent to detected path and adjacent path transmission channel estimation values. A noise power correcting section 21 calculates a corrected noise power ?N0. A weight calculating section 8 receives as its input a frequency-domain transmission channel estimation value H(f) being an output of an FFT section 7 and the noise power ?N0 corrected by the noise power correcting section 21 and calculates a weight of an equalization filter by MMSE.

Abstract: The present invention aims to provide a user selection method which can provide a large, multiuser diversity effect with a small amount of calculation in multiuser MIMO systems, the method being a user selection method for multiuser MIMO communication, in which an orthogonal coefficient is calculated using a received SINR from a projection channel vector by using GS orthogonalization, and using the orthogonal coefficient, a correction SINR is calculated, and using this correction SINR, user selection is performed, and for a next user selection, the projection channel vector is updated, and the above processes are applied to all users.

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 reception quality measuring apparatus of the present invention comprises a first sub-carrier averaging unit for averaging and outputting a channel gain after equalization estimated on the basis of the pilot signal over a sub-carrier, a first power calculation unit for calculating the power of a signal output from the first sub-carrier averaging unit and outputting the same as signal power, a pilot replica generator for generating and outputting a pilot signal replica with respect to a zero-timing signal component based on the zero-timing signal component when a signal x(n) in the time domain after equalization corresponding to the equalized signal is n=0, and also based on a previously set pilot code characteristic, a subtractor for subtracting the pilot signal replica output from the pilot replica generator from the equalized signal and outputting the result as an interference signal, a second power calculation unit for calculating and outputting the power of the interference signal output from the subtrac

Abstract: A receiving apparatus, a receiving method, and a radio communications system are disclosed. The receiving apparatus is for receiving CDMA signals transmitted by M antennas and received by N antennas, where M and N are positive integers. The receiving apparatus includes a multipath receiving signal demodulating unit for primary demodulation of the CDMA signals received by the receiving antennas to obtain estimated transmission signals, and for obtaining signals in a multipath environment of each path of the receiving antennas based on the estimated results. Further, the receiving apparatus includes a multipath interference canceling unit for deducting signals of the paths other than a target path from the signals received by the receiving antennas to obtain multipath interference cancelled signals. Further, the receiving apparatus includes a demodulator for secondary demodulation of the multipath interference cancelled signals.

Abstract: A radio communication system for quickly selecting an optimum transmission mode in accordance with the quality and situation of a propagation path is provided. The system comprises first and second radio communication apparatuses capable of radio-communicating with each other. The first radio communication apparatus comprises a propagation path environment estimator for outputting the estimation result as propagation path environment information, a propagation path quality estimator for outputting the estimation result as propagation path quality, and a transmitter for transmitting both the informations to the second radio communication apparatus. The second radio communication apparatus comprises a transmission mode selector for selecting one of the transmission modes used for communicating with the first radio communication.

Abstract: In an adaptive array antenna receiving apparatus which is used in a CDMA communication system and which includes a predetermined number L (L is an integer greater than 1) of fingers, no correlation exists between respective fingers. An adaptive update algorithm of calculating an antenna weighting factor by the use of an N-order correlation matrix independently for the respective fingers is equivalent to an adaptive update algorithm of calculating an (N×L)-order correlation matrix. In the adaptive array antenna receiving apparatus, the antenna weighting factor is controlled by the use of the adaptive update algorithm independently for the respective fingers so that a mean square of a common error signal produced by a subtractor (8) after rake combination by a rake combining circuit (6) is minimized. In this manner, the amount of calculation in the adaptive update algorithm used in all MMSE control circuits is considerably reduced proportionally from (NL)2 to N2L.

Abstract: A multibeam transmitting/receiving apparatus is provided that is capable of increasing the accuracy of a direction in which a transmission beam is to be transmitted, with a simple arrangement. Signal power measuring units (8-1 through 8-L) of signal processing means (40-1 through 40-L) measure reception signal power levels averaged over a given time, using outputs from reception beam formers (5-1 through 5-L), and indicate the measured reception signal power levels to transmission antenna weight generator (30). Transmission antenna weight generator (30) generates transmission antenna weights, which has been weighted by a reception signal level, from a transmission antenna weight corresponding to reception signal power level P1 and a beam number B1 of a finger having a maximum reception signal power level, and a transmission antenna weight corresponding to reception signal power level P2 and a beam number B2 of a finger having the same path timing as the finger having the maximum reception signal power level.

Abstract: A multi-user receiving apparatus is provided for achieving a reduction in the amount of processing for single-carrier FDMA signals and an improvement in reception characteristics. A DFT unit converts single-carrier FDMA received signals of all users to signals in a frequency domain commonly. A demapping unit selects part of sub-carriers for each user from sub-carriers supplied from the DFT unit. A reception filter separates a user signal and suppresses noise. A demodulator demodulates the user signal, and detects a timing thereof.

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.