Abstract: In a wireless communication system based on an OFDM access system, when forgetting averaging channel estimation is performed, there occurs a phase difference between a present channel estimated value and a past estimated value due to a change of FFT operation timing at a reception side. The error of the channel estimated value caused by the phase difference is corrected. A synchronization catching/tracking unit to determine an operation timing of an FFT from a received signal is provided, and an FFT operation timing difference acquisition section to grasp a change of the operation timing of the FFT generated by the synchronization catching/tracking unit is provided.

Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.

Abstract: A wireless communication which suppresses radio interference between wireless base stations and improves the channel efficiency is implemented. In the wireless communication system including a central base station, a plurality of remote base stations having a direction-variable antenna, and a plurality of mobile stations to communicate with the remote base stations, the central base station performs centralized management of radio-wave beam patterns to be sent to the plurality of mobile stations which will communicate with remote base stations and performs packet scheduling of the mobile stations in such a manner that radio waves sent from the remote base stations will not cause strong interference at the mobile stations.

Abstract: In a transmission apparatus in a MIMO-OFDM communication system employing a cyclic diversity, a cyclic delay controller sets plural delay magnitudes different for respective antennas, in cyclic delayers for each predetermined timing. The cyclic delayers receive symbols subjected to orthogonal frequency division multiplexing, for the respective ones of plural allotted antennas. Besides, the cyclic delayers bestow cyclic delays on the individual symbols of the respective antennas in accordance with plural set delay magnitudes. The symbols cyclically delayed are outputted from the antennas. As the delay magnitudes, a first delay magnitude at a first transmission timing and a second delay magnitude at a second transmission timing are different for one antenna, and the delay magnitudes differ in the respective antennas for one transmission timing. Thus, in a MIMO-OFDM transmission scheme, a frequency diversity and a time diversity are enhanced to heighten a retransmission efficiency in a data retransmission mode.

Abstract: This invention provides a controller of multiplex number in spatial domain that collects from a plurality of radio communication apparatuses the number of terminals connected thereto and the multiplex number in spatial domain, determines the ratio of (the number of terminals connected thereto)/(the multiplex number in spatial domain) for each radio communication apparatus, and adjusts the multiplex number for each radio communication apparatus so that the above ratio will be equal between or among the radio communication apparatuses. The radio communication apparatuses transmit the number of terminals connected thereto and the multiplex number in spatial domain to the controller of multiplex number in spatial domain.

Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.

Abstract: A base station equipment determines, based on a specified condition, whether or not a wireless terminal exists in the vicinity thereof, and then if it exists in the vicinity, the base station equipment transmits information indicating that the base station equipment is ready to communicate with the wireless terminal.

Abstract: In a cellular radio communication system, a base station or a mobile station has a TA (Time Alignment)-range-out detection function, so that when a TA-range-out state that is unable to compensate with a guard interval is detected, the transmission condition of an uplink signal at the mobile station is changed by the mobile station autonomously or by the base station and the mobile station cooperatively.

Abstract: A radio base station apparatus provided with an array antenna having a plurality of antenna elements for calibrating a phase difference among the array antenna elements. The base station has a probe signal adding unit which divides one probe signal and adds the divided probe signals to each receive signals received by the plurality of antenna elements. A probe data extracting unit extracts the probe data from the receive signals added with the probe signal. A phase calibration calculation unit calculates correlating phase calibration values required for calibrating a phase of each receive signal based on the probe data extracted by the probe signal extracting unit. A phase calibration unit calibrates a phase difference among the array antenna elements by calibrating the phase of the each receive signal based on the phase calibration from the phase calibration calculation unit.

Abstract: A pilot signal is estimated by using the sampling theorem to estimate noise power in a stable manner without depending on the signal to noise ratio. A pilot signal estimation section obtains an estimated pilot signal by using the sampling theorem according to a plurality of received pilot signals sampled in the frequency domain by a sampling processor. A noise power estimation section estimates noise power by applying statistical averaging to the difference between the received pilot signal received from the sampling processor and the estimated pilot signal received from the pilot signal estimation section.

Abstract: A non-terminated packet is transmitted, by utilizing a spatial layer responded with an ACK, which is assumed as a released layer. Alternatively, a non-terminated packet is transmitted by using a released layer and an original spatial layer in combination. Alternatively, a new packet is transmitted in a released layer by utilizating time till termination of transmission of a non-terminated packet. A wireless communication system effectively utilizing a released layer, a terminal and a base station.

Abstract: A signal transmission and reception method, and a base station and a mobile terminal therefor are disclosed. In a communication system including a base station and at least a mobile terminal, the transmission of the data signal from the base station to each mobile terminal is controlled in accordance with the manner in which the pilot signal transmitted from the base station to each mobile terminal is received by the mobile terminal. In the signal transmission method, the proper one of a plurality of signal multiplexing schemes is selected based on the control signal received from each mobile terminal, and the transmission signal is multiplexed by the selected signal multiplexing scheme and transmitted to each mobile terminal. The transmission signal includes the data signal and the dedicated pilot signal transmitted to the mobile terminal.

Abstract: In a wireless communication system wherein at least two communication units employ the TDD wireless communication method based on OFDMA, an OFDM wireless communication method and a wireless communication apparatus are disclosed. The first communication unit transmits a pilot signal over the whole subband zone configured of divisions of a predetermined system band. The second communication unit having a plurality of antennas estimates a propagation path of the subchannels constituting continuous frequency blocks making up a subband from the pilot signal received. The second communication unit determines the array weight used at the time of signal transmission to the first communication unit using the estimation result.

Abstract: A radio communication apparatus enhances cell throughput by adaptive selection of spatially multiplexed channels in consideration of interferences in a local cell and reducing load for calculation of array weights by storing them in advance as fixed values and outputting fixed beams. To reduce the calculation load for the adaptive selection of spatially multiplexed channels that takes interferences within the local cell into consideration, the radio communication apparatus adopts a packet scheduling method that selects a combination of fixed beams and determines the number of spatially multiplexed channels, based on the fixed beams for mobile apparatuses with packets waiting to be transmitted and pre-calculated correlative quantities of inter-beam interferences between these fixed beams.

Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.

Abstract: There are provided scheduling and a resend control system, which match simultaneous communications using a plurality of carriers. For individual carriers to be used, the simultaneous resend control of the carriers is made by notifying channel information and a data decoding result and by managing the resend numbers. Even in case the communications are performed by using the carriers simultaneously between a base station and a terminal, the scheduling can be done to contain the resend control. It is also possible to improve the communication quality and the throughput.

Abstract: A method for preventing or correcting the imbalance in load among interlaces in communications based on CDMA whereby communication resources are allocated to the respective interlaces through an interlacing scheme. A base station measures load information on an interlace-by-interlace basis, and notifies the same to a terminal while the terminal filters the load information to utilize the same for making a decision on transmission timing. Or the base station notifies the terminal of load information on plural transmission timings, and the terminal selects an adequate transmission timing to be then utilized. Otherwise, the base station presents at least two probabilities of transition between interlaces, urging the terminal to update an interlace (transmission timing) on a probabilistic basis.

Abstract: A radio base station apparatus provided with an array antenna having a plurality of antenna elements for calibrating a phase difference among the array antenna elements. The base station has a probe signal adding unit which divides one probe signal and adds the divided probe signals to each receive signals received by the plurality of antenna elements. A probe data extracting unit extracts the probe data from the receive signals added with the probe signal. A phase calibration calculation unit calculates correlating phase calibration values required for calibrating a phase of each receive signal based on the probe data extracted by the probe signal extracting unit. A phase calibration unit calibrates a phase difference among the array antenna elements by calibrating the phase of the each receive signal based on the phase calibration from the phase calibration calculation unit.

Abstract: An antenna pattern assigning method capable of avoiding interference between a plurality of base transmission stations constituting a radio system in a cellular type broad band communication. In the radio system, when assigning a fixed beam pattern different for each frequency, each of the radio base transmission station devices transmits a radio wave having a directivity pattern having a peak in the same direction in two or more different frequencies, and between adjacent radio base transmission station devices, radio transmission is performed by using different directivity patterns in the two or more frequencies.

Abstract: This invention provides a controller of multiplex number in spatial domain that collects from a plurality of radio communication apparatuses the number of terminals connected thereto and the multiplex number in spatial domain, determines the ratio of (the number of terminals connected thereto)/(the multiplex number in spatial domain) for each radio communication apparatus, and adjusts the multiplex number for each radio communication apparatus so that the above ratio will be equal between or among the radio communication apparatuses. The radio communication apparatuses transmit the number of terminals connected thereto and the multiplex number in spatial domain to the controller of multiplex number in spatial domain.