Abstract: Channel estimator 101, based on the received signal received through a radio channel, estimates an estimated value of a channel showing channel characteristics of the radio channel. Correlation value calculator 103 calculates a time domain channel correlation value showing the time correlation of the radio channel, based on the estimated value of the channel. Channel power calculator 102 calculates channel power as the power of the received signal, based on the estimated value of the channel. Noise power calculator 104 calculates noise power as the power of the noise component contained in the received signal. Corrector 105 corrects the channel power based on the noise power and corrects the time domain channel correlation value based on the corrected channel power and the noise power. Fading Doppler frequency estimator 200 estimates the fading Doppler frequency based on the corrected time domain channel correlation value.

Abstract: Channel estimator 101, based on the received signal received through a radio channel, estimates an estimated value of a channel showing channel characteristics of the radio channel. Correlation value calculator 103 calculates a time domain channel correlation value showing the time correlation of the radio channel, based on the estimated value of the channel. Channel power calculator 102 calculates channel power as the power of the received signal, based on the estimated value of the channel. Noise power calculator 104 calculates noise power as the power of the noise component contained in the received signal. Corrector 105 corrects the channel power based on the noise power and corrects the time domain channel correlation value based on the corrected channel power and the noise power. Fading Doppler frequency estimator 200 estimates the fading Doppler frequency based on the corrected time domain channel correlation value.

Abstract: Suppressed is occurrence of false preamble detection in a preamble detection device for detecting a preamble sequence which is sent to it by the use of a physical random access channel. A preamble detection device includes a first threshold calculation unit (203) for calculating a first threshold value from average interference power; a second threshold calculation unit (205) for calculating cross-correlation values between a received signal and respective ones of all preamble sequences possibly to be sent, and calculating a second threshold value from the cross-correlation values; a comparison unit (208) for comparing the first threshold value with the second threshold value, and setting the larger one of the threshold values to be a detection threshold value; and a detection unit (209) for detecting a preamble sequence giving a cross-correlation value larger than the detection threshold value as a received preamble sequence.

Abstract: In a reception method and a receiver, a base station corrects a frequency offset contained in a reception signal from each user terminal and realizes excellent reception characteristics by using a simple receiver mechanism for performing frequency domain processing in a radio system using a frequency division multiplex (FDM) method.

Abstract: A receiving device includes a channel estimating section that performs a correlating process for a received reference signal in which a single carrier signal was transformed into a frequency domain signal and a pre-stored reference signal so as to obtain estimated channel values; a compensation coefficient computing section that computes compensation coefficients corresponding to residual multipath interferences based on a bit likelihood; a weight computing section that computes equalized weights based on the estimated channel values and the compensation coefficients; an equalizing filter that generates an equalized signal by equalizing process for the received signal that is the frequency domain signal based on the equalized weights; a residual interference replica generating section that generates residual multipath interference replicas based on frequency domain symbol replicas, the estimated channel values, and the equalized weights; and a subtracting section that subtracts the residual multipath interfer

Abstract: A coherent bandwidth calculation unit (41) calculates a coherent bandwidth based on a channel response in the time domain obtained from reception signals (R1-RN) for each path between transmitting antennas and receiving antennas. A weight calculation control unit (42) determines target subcarriers of equalization weight calculation based on the coherent bandwidth. A weight calculation unit (31) calculates the equalization weight of each target subcarrier. A weight interpolation unit (43) performs interpolation processing using the equalization weights so as to obtain equalization weights for the subcarriers that have not undergone equalization weight calculation yet.

Abstract: The present invention provides a channel estimation apparatus in which channel estimation may be made higher than heretofore in accuracy and may be used for calculating the weight for an equalization filter to achieve an optimum equalizing performance. A subcarrier copying unit 20 copies K items of end-side subcarriers, using the channel estimation obtained by a correlation processing unit 14 and K which is a subcarrier copy number. An IDFT unit 15 transforms the channel estimation obtained at the subcarrier copying unit 20 into the time domain channel response. A noise path removing unit 16 removes noise paths from the channel response output from the IDFT unit 15. A DFT unit 17 performs DFT of the channel response, from which the noise paths are removed by the noise path removing unit 16, to output a noise-suppressed frequency domain channel estimation value. A weight calculation unit 5 inputs the frequency domain channel estimation value output from the DFT unit 17 to calculate an equalizing weight.

Abstract: Disclosed is a MIMO receiving apparatus in which a residual interference calculation unit (17) inputs noise-suppressed frequency domain channel estimation values, output from FFT units (12-1-1 to 12-M-N), equalizing weights calculated by a weight calculating unit (13), equalized signals from equalization processing by an equalization filter (14) and reference signals generated by reference signal generating units (16-1 to 16-M) to calculate a residual interference, and the likelihood correction units (18-1 to 18-M) receive time domain equalized signal from the IDFT units (15-1 to 15-M) and the residual interference calculated by the residual interference calculation unit (17) to correct the likelihood of the equalized signal (FIG.1).

Abstract: In a MIMO receiving apparatus, the 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 ranges. In this MIMO receiving apparatus, interference replicas of the antennas are eliminated from the received signals (by subtractor 54) before equalizing the two-dimensional frequency ranges, and non-distortion signal replicas are added (by a demodulating part 55) to the signals from which the interference replicas of the antennas have been eliminated after equalizing the two-dimensional frequency ranges.

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 equalizing section 8 performs multipath equalization and other cell interference suppression to the desired user signal in a frequency domain.

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 receiving device includes a channel estimating section that performs a correlating process for a received reference signal in which a single carrier signal was transformed into a frequency domain signal and a pre-stored reference signal so as to obtain estimated channel values; a compensation coefficient computing section that computes compensation coefficients corresponding to residual multipath interferences based on a bit likelihood; a weight computing section that computes equalized weights based on the estimated channel values and the compensation coefficients; an equalizing filter that generates an equalized signal by equalizing process for the received signal that is the frequency domain signal based on the equalized weights; a residual interference replica generating section that generates residual multipath interference replicas based on frequency domain symbol replicas, the estimated channel values, and the equalized weights; and a subtracting section that subtracts the residual multipath interfer

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 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 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 coherent bandwidth calculation unit (41) calculates a coherent bandwidth based on a channel response in the time domain obtained from reception signals (R1-RN) for each path between transmitting antennas and receiving antennas. A weight calculation control unit (42) determines target subcarriers of equalization weight calculation based on the coherent bandwidth. A weight calculation unit (31) calculates the equalization weight of each target subcarrier. A weight interpolation unit (43) performs interpolation processing using the equalization weights so as to obtain equalization weights for the subcarriers that have not undergone equalization weight calculation yet.

Abstract: Disclosed is a MIMO receiving apparatus in which a residual interference calculation unit (17) inputs noise-suppressed frequency domain channel estimation values, output from FFT units (12-1-1 to 12-M-N), equalizing weights calculated by a weight calculating unit (13), equalized signals from equalization processing by an equalization filter (14) and reference signals generated by reference signal generating units (16-1 to 16-M) to calculate a residual interference and the likelihood correction units (18-1 to 18-M) receive time domain equalized signal from the IDFT units (15-1 to 15-M) and the residual interference calculated by the residual interference calculation unit (17) to correct the likelihood of the equalized signal.

Abstract: The present invention provides a channel estimation apparatus in which channel estimation may be made higher than heretofore in accuracy and may be used for calculating the weight for an equalization filter to achieve an optimum equalizing performance. A subcarrier copying unit 20 copies K items of end-side subcarriers, using the channel estimation obtained by a correlation processing unit 14 and K which is a subcarrier copy number. An IDFT unit 15 transforms the channel estimation obtained at the subcarrier copying unit 20 into the time domain channel response. A noise path removing unit 16 removes noise paths from the channel response output from the IDFT unit 15. A DFT unit 17 performs DFT of the channel response, from which the noise paths are removed by the noise path removing unit 16, to output a noise-suppressed frequency domain channel estimation value. A weight calculation unit 5 inputs the frequency domain channel estimation value output from the DFT unit 17 to calculate an equalizing weight.