Abstract: In one embodiment, a relay station (11) receives a first radio signal into which transfer information to be transmitted to a mobile station (12) is encoded from a donor base station (10) through a backhaul link. When the transfer information encoded into the first radio signal is unicast information addressed to the mobile station (12), the relay station (11) decodes the unicast information and generates a third radio signal into which the unicast information is re-encoded. Further, the relay station (11) is configured such that when the transfer information encoded into the first radio signal is multicast information, the relay station (11) is able to omit decoding the multicast information. In this way, multicast information that is delayed from the predefined transmission timing is prevented from being transmitted from the relay station (11).

Abstract: There is obtained a frequency correction circuit capable of correcting the frequency errors of received signals with high accuracy and preventing the degradation of demodulated signals, while further suppressing an increase in the circuit scale. A frequency correction circuit according to the present invention includes a demodulation means that gives respective preset frequency offsets corresponding to a plurality of frequency errors to received radio signals and demodulates said received radio signals by utilizing respective ones of a plurality of preset in-phase summation periods, and a selection means that selects one demodulated signal from among a plurality of demodulated signals demodulated by said demodulation means.

Abstract: A frequency correction circuit that gives plural frequency offsets to a received radio signal in order to correct a frequency error of the radio signal, demodulates the radio signal, combines an arbitrary number of demodulation signals as combined demodulation signals from among plural demodulation signals, and selects one demodulation signal or combined demodulation signal from among the demodulation signals and the combined demodulation signals.

Abstract: To provide a communication device in which an operation of demodulating a reception signal can be performed with good accuracy. The communication device controls a parameter used when the reception signal is demodulated by a demodulation unit (104) according to an estimated frequency offset that is estimated from the reception signal and information obtained from the estimated frequency offset.

Abstract: A channel estimation circuit (12) of an individual CH path demodulation unit (1A-1L) performs a channel estimation from an individual CH. A channel estimation value correction circuit (22) of a shared CH path demodulation unit (2A-2L) then corrects a reception power fluctuation due to uplink transmission power control which is caused by the timing offset between the individual CH and the shared CH. The resultant data is used for the demodulation by a shared CH demodulation circuit (23).

Abstract: A radio channel estimation result which is an estimation result of a state of a propagation path to a mobile terminal that is a communication target, is generated. Whether a correction operation for correcting a frequency drift of a radio frequency used in radio communication between a radio base station and the mobile terminal has converged or not is determined. Then, a moving speed of the mobile terminal is estimated using only the radio channel estimation result at the time when the correction operation has converged.

Abstract: A frequency correction circuit that gives plural frequency offsets to a received radio signal in order to correct a frequency error of the radio signal, demodulates the radio signal, combines an arbitrary number of demodulation signals as combined demodulation signals from among plural demodulation signals, and selects one demodulation signal or combined demodulation signal from among the demodulation signals and the combined demodulation signals.

Abstract: To provide a multibeam antenna reception device capable of improving the reception quality while suppressing an increase in the amount of computation. The multibeam antenna reception device includes a path detection control section (108) for controlling the path detection range at the current time for M receive beam path detection sections (1061 to 106M) based on pairs of receive beam numbers and path delays detected prior to the current time and information on user signal reception quality in the pairs of the receive beam numbers and the path delays output from the M receive beam path detection sections (1061 to 106M). When path detection is performed with respect to each user in the M receive beam path detection sections (1061 to 106M), pairs of receive beam numbers and path delays and information on user signal reception quality in the pairs of the receive beam numbers and the path delays are detected according to the path detection range controlled by the path detection control section (108).

Abstract: A multi-beam antenna transmitter/receiver includes reception beam formation units (1041-104M) which form a plurality of reception beams, and transmission beam formation units (1131-113J) which form a plurality of transmission beams. The multi-beam antenna transmitter/receiver further includes reception beam calculation units (1081-108M) which calculate overall reception qualities from the reception qualities for the path delays of user signals for respective reception beams, and a transmission beam selection unit (109) which selects a reception beam excellent in overall reception quality and selects a transmission beam having a direction which coincides with or is close to the direction of the selected reception beam. An optimum transmission beam can be selected even in the multipath environment.

Abstract: A channel estimation circuit (12) of an individual CH path demodulation unit (1A-1L) performs a channel estimation from an individual CH. A channel estimation value correction circuit (22) of a shared CH path demodulation unit (2A-2L) then corrects a reception power fluctuation due to uplink transmission power control which is caused by the timing offset between the individual CH and the shared CH. The resultant data is used for the demodulation by a shared CH demodulation circuit (23).

Abstract: According to a transmitter-receiver of a mobile communication system of the present invention, it is possible to preferably perform the communication with a desired user without deteriorating the quality of service of an interference user even when the desired user and the interference user are present in the same direction. Therefore, by selecting a path level on a two-dimensional profile larger than a predetermined threshold or a path having the ratio of signal power to interference power or signal power larger than the predetermined threshold, a plurality of paths respectively having preferable reception quality are selected. Then, interference powers included in received signals of the paths are calculated, a path having minimum interference power is selected, and the DOA of the path is used as a downlink-signal transmitting direction.

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: To provide a multibeam antenna reception device capable of improving the reception quality while suppressing an increase in the amount of computation. The multibeam antenna reception device includes a path detection control section (108) for controlling the path detection range at the current time for M receive beam path detection sections (1061 to 106M) based on pairs of receive beam numbers and path delays detected prior to the current time and information on user signal reception quality in the pairs of the receive beam numbers and the path delays output from the M receive beam path detection sections (1061 to 106M). When path detection is performed with respect to each user in the M receive beam path detection sections (1061 to 106M), pairs of receive beam numbers and path delays and information on user signal reception quality in the pairs of the receive beam numbers and the path delays are detected according to the path detection range controlled by the path detection control section (108).

Abstract: In a CDMA receiving apparatus according to the present invention, a delay spread calculation unit calculates a delay spread based on timings and levels of paths equal to or higher than a path level threshold, and a same-path detection time range calculation unit calculates a same-path detection time range in accordance with the delay spread. A finger-assigned path selector unit selects finger-assigned paths from paths equal to or higher than the path level threshold starting in order from the one having the highest path, and excludes paths within the same-path detection time range centered at each selected path, from candidates for finger-assigned paths, from the next selection onward. Then, a demodulation processing unit demodulates a received signal using the path timings of the finger-assigned paths as synchronization timings.

Abstract: A multi-beam antenna transmitter/receiver includes reception beam formation units (1041-104M) which form a plurality of reception beams, and transmission beam formation units (1131-113J) which form a plurality of transmission beams. The multi-beam antenna transmitter/receiver further includes reception beam calculation units (1081-108M) which calculate overall reception qualities from the reception qualities for the path delays of user signals for respective reception beams, and a transmission beam selection unit (109) which selects a reception beam excellent in overall reception quality and selects a transmission beam having a direction which coincides with or is close to the direction of the selected reception beam. An optimum transmission beam can be selected even in the multipath environment.

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: An array antenna transmitter/receiver has an array antenna (10) composed of antenna elements and radio transmitting/receiving units (30-1 to 30-n) provided to the respective antenna elements, wherein calibration signals are generated at given time intervals in a burst, the calibration signals are subjected to frequency conversion, the frequency-converted calibration signals are fed to the radio transmitting/receiving units (30-1 to

Abstract: The adaptive receiving block 2k for the k-user generates a receiving signal by the k-th user the m-th path inherent antenna directivity pattern respectively, obtains the k-th user demodulation signal by demodulating and adding for each path simultaneously and outputs weight control error signal e′kl˜e′kM for the purpose of forming directivity pattern for each path. The weight control error synthesis circuit 3 optionally synthesizes weight control error signal e′kl˜e′kM and outputs synthesis weight control error signal e′kl˜e′km. Synthesizing weight control error signals with respect to paths whose arrival directions of multi-path of each user are close, performing a control without synthesizing weight control errors with respect to paths whose arrival directions are apart, increasing the information available for adaptive control and enhancing an adaptive control characteristic and an interference suppression ability.

Abstract: Calibration signals which were generated in a signal generator 107 for calibration and to which frequency conversion was applied in a radio transmitting section 108 for calibration are made to be power levels in power level variable circuits 109-1 to 109-N so that power levels of calibration signals extracted in a signal processing section 106 for calibration become constant, and are multiplied by signals received at antenna elements 102-1 to 102-N in multiplex circuits 103-1 to 103-N.

Abstract: Calibration signals which were generated in a signal generator 107 for calibration and to which frequency conversion was applied in a radio transmitting section 108 for calibration are made to be power levels in power level variable circuits 109-1 to 109-N so that power levels of calibration signals extracted in a signal processing section 106 for calibration become constant, and are multiplied by signals received at antenna elements 102-1 to 102-N in multiplex circuits 103-1 to 103-N.