Abstract: A base station device includes: a receiver, which, in operation, receives signals from one or more other base station devices in a system using an adjacent frequency band; a searcher, which, in operation, searches for one or more center frequencies of signals from the one or more other base station devices; a selector, which, in operation, selects a synchronization target base station device from which a respective center frequency has been acquired from among the one or more other base station devices; and a controller, which, in operation, sets an operation parameter to establish synchronization with transmission and reception timings of the synchronization target base station device.

Abstract: A communication device includes: receiving circuitry which, in operation, receives a radio signal transmitted by a mobile station; and processing circuitry which, in operation, estimates a position of the mobile station based on a signal waveform profile including information about at least two of a direction of arrival, an arrival time, and a received power of the radio signal. A position estimating method includes: receiving a radio signal transmitted by a mobile station; and estimating a position of the mobile station based on a signal waveform profile including information about at least two of a direction of arrival, an arrival time, and a received power of the radio signal. A communication system includes: a mobile station; and a communication device.

Abstract: A base station device includes: a receiver, which, in operation, receives signals from one or more other base station devices in a system using an adjacent frequency band; a searcher, which, in operation, searches for one or more center frequencies of signals from the one or more other base station devices; a selector, which, in operation, selects a synchronization target base station device from which a respective center frequency has been acquired from among the one or more other base station devices; and a controller, which, in operation, sets an operation parameter to establish synchronization with transmission and reception timings of the synchronization target base station device.

Abstract: A base station receives signals transmitted from one terminal in cooperation with another base station and performs synthesis processing of the received signals of the other base station and the received signals of the local base station. In the base station, a determination circuit determines necessity of synthesis processing using the received signals of the local base station at the time of the first transmission of the terminal. A base station-to-base station communication circuit transmits a message requesting forwarding of the received signals to the other base station in a case where the synthesis processing is determined to be necessary and receives the forwarded signals that are forwarded from the other base station at the time of retransmission of the terminal. A synthesis circuit synthesizes the forwarded signals from the other base station and the received signals of the local base station in a case where the synthesis processing is determined to be necessary.

Abstract: A base station receives signals transmitted from one terminal in cooperation with another base station and performs synthesis processing of the received signals of the other base station and the received signals of the local base station. In the base station, a determination circuit determines necessity of synthesis processing using the received signals of the local base station at the time of the first transmission of the terminal. A base station-to-base station communication circuit transmits a message requesting forwarding of the received signals to the other base station in a case where the synthesis processing is determined to be necessary and receives the forwarded signals that are forwarded from the other base station at the time of retransmission of the terminal. A synthesis circuit synthesizes the forwarded signals from the other base station and the received signals of the local base station in a case where the synthesis processing is determined to be necessary.

Abstract: It is possible to provide an SC-FDMA transmission device and an SC-FDMA transmission signal formation method which improve the transmission efficiency of the SC-FDMA transmission signal. The SC-FDMA transmission device (100) performs the discrete Fourier transform process on a primary modulation signal sequence formed by N primary modulation symbols to obtain a plurality of frequency components, which are respectively mapped onto different subcarriers. The obtained SC-FDMA symbol is subjected to the inverse Fourier transform process before being transmitted. A propagation path information decoding unit (155) acquires frequency selection characteristic in a propagation path to/from a reception side. A cyclic shift unit (110) and a correlation characteristic judgment unit (115) adjust the frequency response of the SC-FDMA symbol according to the frequency selection characteristic.

Abstract: A first conversion unit (201) converts a signal from a time domain to a frequency domain. A signal extraction unit (202) extracts common channel information included in the signal which has been converted by the first conversion unit (201). A signal substitution unit (207) restores the common channel information which has been extracted by the signal extraction unit (202). An addition unit (208) substitutes the common channel information which has been restored by the signal substitution unit (207) for the common channel information included in the signal which has been converted by the first conversion unit (201). A second conversion unit (209) converts the signal including the common channel information substituted, which has been converted by the first conversion unit (201), from the frequency domain to the time domain.

Abstract: Provided is a communication capacity evaluating apparatus whereby the communication capacity can be grasped and the necessity of changing the content of a dead spot measure after the placement of a relay apparatus can be eliminated. In the communication capacity evaluating apparatus, a system information analyzing unit (121) acquires, from a received signal, used-band information of the communication using a MIMO mode. An S/N calculating unit (122) analyzes the received signal to determine a signal-to-noise ratio. A channel estimating unit (123) analyzes the received signal to determine a channel matrix. A throughput limit calculating unit (124) calculates the limit value of the communication capacity on the basis of the used-band information, information about the number of transmission antennas of a base station (180), information about the number of reception antennas of a radio relay apparatus (100) stored in advance, the signal-to-noise ratio and the channel matrix.

Abstract: It is possible to provide an SC-FDMA transmission device and an SC-FDMA transmission signal formation method which improve the transmission efficiency of the SC-FDMA transmission signal. The SC-FDMA transmission device (100) performs the discrete Fourier transform process on a primary modulation signal sequence formed by N primary modulation symbols to obtain a plurality of frequency components, which are respectively mapped onto different subcarriers. The obtained SC-FDMA symbol is subjected to the inverse Fourier transform process before being transmitted. A propagation path information decoding unit (155) acquires frequency selection characteristic in a propagation path to/from a reception side. A cyclic shift unit (110) and a correlation characteristic judgment unit (115) adjust the frequency response of the SC-FDMA symbol according to the frequency selection characteristic.