Abstract: The present invention is designed to provide a communication system, a base station apparatus, a terminal apparatus and a communication method that can support the diversification of communication. In the communication system of the present invention, in which a terminal apparatus receives a downlink data signal transmitted from a base station apparatus (eNB) in a radio resource region for a downlink data signal, the base station apparatus transmits a terminal-specific reference signal in the radio resource region for the downlink data signal to the terminal apparatus (UE), and the terminal apparatus measures channel quality information based on the terminal-specific reference signal and transmits the measured channel quality information to the base station apparatus.

Abstract: A beam selection method in a mobile communication system including a base station with multiple antennas and user equipment conducting radio communication with the base station includes the steps of, at the base station, detecting a direction in which the user equipment is located, transmitting precoded reference signals toward the detected direction by spatial multiplexing using same frequency and time resources, and determining a beam for the user equipment based upon feedback information from the user equipment.

Abstract: The present disclosure relates to techniques for implementing efficient beam forming in 3D MIMO. One aspect of the present invention relates to abase station, comprising: a beam forming unit configured to form multiple directional beams in accordance with a predetermined beam arrangement; a transmission and reception unit configured to transmit reference signals in the formed multiple directional beams; and a feedback information acquisition unit configured to acquire feedback information from user equipment receiving the reference signals.

Abstract: A base station apparatus, a user terminal, a communication system and a communication control method that can support the diversification of communication is provided. In a base station apparatus, downlink measurement object signals are pre-coded using precoding weights that are specific to a user terminal, and transmitted to the user terminal, and, in the user terminal, the downlink measurement object signals are demodulated using the precoding weights that are specific to the user terminal, and measurement processes are performed based on the demodulated downlink measurement object signals.

Abstract: Provided are a receiver, a transmitter and a radio communication method capable of using non-orthogonal multiple access while suppressing cost increase and processing delay. A mobile station 200A receives non-orthogonal signals, also receives a reference signal to be used for interference cancellation, and extracts the non-orthogonal signal addressed to the mobile station 200A from the received non-orthogonal signals by demodulating and cancelling the radio signal addressed to another mobile station. In addition, the mobile station 200A demodulates the extracted non-orthogonal signal addressed to the mobile station 200A on the basis of the reference signal. The reference signal is multiplexed in the same radio resource block as a resource block allocated to the non-orthogonal signals, and is multiplexed in the radio resource block only when at least one signal is scheduled in the radio resource block.

Abstract: A radio communication system includes a first base station that is identified by a first cell identity, a second base station that is identified by a second cell identity, and a user device that can perform radio communication with each of the base stations. The user device detects a first transmission timing based on a first synchronization signal from the first base station and establishes synchronization with the first base station. The first base station notifies the user device of synchronization state information related to a synchronization state with the second base station and of frequency information related to an identification signal frequency that is used by the second base station to transmit an identification signal. The user device, based on the synchronization state information, performs identifying processing, on the identification signal frequency indicated by the frequency information, to identify the second cell identity indicated by the identification signal.

Abstract: A radio base station that communicates with a user terminal, and has a control section that executes control so that signals are time-division-multiplexed over a first radio resource region where symbols are multiplexed at a rate equal to or below a Nyquist rate and a second radio resource region where symbols are multiplexed at a faster rate than the Nyquist rate. The radio base station also includes a transmission section that transmits the signals that are time-division-multiplexed in the first radio resource region and the second radio resource region, to the user terminal to reduce the interference against predetermined signals in a radio communication system in which Faster-Than-Nyquist (FTN) is used.

Abstract: A user terminal with a transmission processing section that generates an SC-FDMA (Single Carrier Frequency Division Multiple Access) signal by blocking symbols that are arranged in a given time region at a symbol rate equal to or lower than a Nyquist rate. The transmission processing section converts the blocks into symbols that are multiplexed in a high density, in block units, in the time domain, by allowing an overlap between the symbols in the blocks. The user terminal also includes a transmission section that transmits the SC-FDMA signal to a radio base station to improve uplink throughput.

Abstract: The present invention is designed to provide a communication system, a local area base station apparatus, a mobile terminal apparatus and a communication method that can provide highly efficient local area radio access. In a communication system in which a mobile terminal apparatus performs radio communication with a wide area base station apparatus that covers a wide area, using a first carrier frequency, and performs radio communication with a local area base station apparatus that covers a local area, using a second carrier frequency, the wide area base station apparatus allocates different frequencies between the uplink and the downlink in the first carrier frequency and communicates with the mobile terminal apparatus, and the local area base station apparatus dynamically switches between the uplink and the downlink in the second carrier frequency on a per time basis based on the communication environment, and communicates with the mobile terminal apparatus.

Abstract: In user equipment for communicating with a base station in a radio communication system including the base station and the user equipment, the user equipment includes a receiver that measures received power of reference signals associated with a plurality of different identification information items, the reference signals being transmitted from the base station, and that selects a specific reference signal based on a measurement result; and a transmitter that transmits a random access signal including a preamble sequence, the preamble sequence corresponding to the identification information item of the reference signal selected by the receiver.

Abstract: The object is achieved by providing a base station apparatus for performing time and frequency scheduling in uplink packet access with: an interference amount measurement part configured to measure an uplink interference amount for each interference amount measurement unit which comprises a predetermined period and a predetermined number of frequency blocks; an interference amount determination part configured to determine whether the uplink interference amount satisfies a predetermined condition; and an overload indicator reporting part configured to report an overload indicator to a neighboring cell when the predetermined condition is satisfied.

Abstract: Provided are a receiver, a transmitter and a radio communication method capable of using non-orthogonal multiple access while suppressing cost increase and processing delay. A mobile station 200A receives non-orthogonal signals, also receives a reference signal to be used for interference cancellation, and extracts the non-orthogonal signal addressed to the mobile station 200A from the received non-orthogonal signals by demodulating and cancelling the radio signal addressed to another mobile station. In addition, the mobile station 200A demodulates the extracted non-orthogonal signal addressed to the mobile station 200A on the basis of the reference signal. The reference signal is multiplexed in the same radio resource block as a resource block allocated to the non-orthogonal signals, and is multiplexed in the radio resource block only when at least one signal is scheduled in the radio resource block.

Abstract: A radio base station with a transmission processing section that converts a symbol allocated at a higher symbol rate than a Nyquist rate in a given time domain and/or frequency domain into a symbol allocated at a symbol rate of the Nyquist rate or less in the given time domain and/or frequency domain to generate an OFDMA (Orthogonal Frequency Division Multiple Access) signal for each of a plurality of antennas. The radio base station also includes a transmission section that transmits the 01-DMA signal of each of the plurality of antennas to a user terminal, where the transmission processing section applies transmit diversity with the plurality of antennas to the symbol allocated at the higher symbol rate to improve throughput in a radio communication system using transmit diversity.

Abstract: The present disclosure relates to techniques for reducing flash light effect in 3D MIMO. One aspect of the present invention relates to user equipment, comprising: a transmission and reception unit configured to receive an interference beam candidate list including directional beams transmitted from a camped base station and interference beam candidates transmitted from an adjacent base station; a measurement unit configured to measure reception quality of reference signals transmitted in the respective directional beams in the received interference beam candidate list; and an interference information generation unit configured to generate interference information based on the measured reception quality, wherein the transmission and reception unit indicates the generated interference information to the camped base station or the adjacent base station.

Abstract: The present invention is designed to reduce the overhead of reference signals for measuring CSI in high-order MIMO multiplexing technique. A radio base station is used in a radio communications system of a frequency division duplexing (FDD) scheme, and has a receiving section that receives reference signals for measuring time division duplex (TDD) channel state information, transmitted from a plurality of antennas provided in a user terminal, a measurement section that measures the channel state information, in a plurality of receiving antennas, by using the reference signals, a generation/selection section that generates an optimal precoding vector from the channel state information measured in each receiving antenna, or selects the optimal precoding vector from a set of precoding vectors that is defined in advance, and a transmission section that transmits a physical downlink shared channel, in MIMO multiplexing transmission, by using the precoding vector selected in the generation/selection section.

Abstract: A user apparatus configured to perform communication with a base station in a radio communication including the base station and the user apparatus, including: a transmission unit configured to transmit a plurality of uplink signals by a plurality of antenna ports or beams; and a reception unit configured to receive, from the base station that monitors the plurality of uplink signals, identification information of a specific uplink signal received by the base station; wherein the transmission unit transmits a data signal using an antenna port or a beam corresponding to an uplink signal that is identified by the identification information received by the reception unit.

Abstract: A user apparatus configured to communicate with a base station in a radio communication system including a base station and the user apparatus, including: first reference signal reception means configured to measure a received power of first reference signals, transmitted from the base station, that are associated with a plurality of different identifiers, and to select a specific first reference signal; report means configured to report an identifier and a received power of the first reference signal selected by the first reference signal reception means to the base station or a macro cell base station; second reference signal reception means configured to receive a plurality of second reference signals transmitted from the base station; and measurement means configured to measure a reception quality of the second reference signals received by the second reference signal reception means, and to transmit feedback information based on the reception quality to the base station.

Abstract: A mobile station includes: a physical channel segmentation unit to receive radio signals including multiple orthogonal signals which are orthogonal to each other, and multiple non-orthogonal signals which are not orthogonal to each other; and data demodulating/decoding units to extract the non-orthogonal signal addressed to the mobile station from the multiple non-orthogonal signals by demodulating and cancelling the radio signal addressed to another mobile station by use of the orthogonal signals included in the radio signals received by the physical channel segmentation unit, and demodulate the signal included in the orthogonal signals and addressed to the mobile station, and the extracted non-orthogonal signal addressed to the mobile station.

Abstract: Two alternative embodiments are disclosed to enable a user equipment to efficiently discover small cells using a secondary carrier. The user equipment has a primary carrier link to a base station. In addition, the user equipment has a secondary carrier link to a network node in a small cell within a macro cell supported by the base station. The small cells are discovered through novel beacon signals or through modified PSS/SSS transmissions.

Abstract: A user equipment is disclosed including a first receiving section that receives control information in a first cell and a second receiving section that receives a detection signal in a second cell based on the control information. In the second cell, the control information is used to specify a radio resource to which the detection signal is allocated.