Abstract: In a radio transmission device, an orthogonal frequency division multiplexing (OFDM) signal forming unit forms an OFDM signal by arranging pilot signals according to a pilot arrangement pattern. According to the pilot arrangement pattern, among a plurality of pilot arrangement subcarriers with an NPilot_Freq-subcarrier interval, in a plurality of first pilot arrangement subcarriers with an NPilot_SPA-subcarrier interval, pilot signals for phase noise estimation are arranged in all resource elements. An information symbol and a pilot symbol are mapped to different resource elements. Among the plurality of pilot arrangement subcarriers with the NPilot_Freq-subcarrier interval, in a plurality of second pilot arrangement subcarriers excluding the plurality of first pilot arrangement subcarriers, the pilot signals for phase noise estimation are arranged in a cycle of NPilot_Time resource elements in the time domain.

Abstract: A modulation apparatus capable of performing highly efficient multiplexing of pilot signals used for equalization and estimation of phase noises for LOS-MIMO (Line Of Sight-Multiple Input Multiple Output) using a single-carrier signal is provided. The modulation apparatus (10) includes means (11) for transforming a time-domain pilot signal sequence into a first number of frequency-domain signals corresponding to a sequence length of the pilot signal sequence, means (12) for mapping the first number of frequency-domain signals at the same number of subcarrier intervals as a number of transmitting antennas of the modulation apparatus by shifting mapping positions of heads of the frequency-domain signals one after another by an amount equivalent to one subcarrier so that the frequency-domain signals do not overlap each other, and means (13) for transforming the mapped frequency-domain signals into time-domain signals.

Abstract: A base station for transmitting a synchronization signal from N transmission antennas (N>=2) in orthogonal frequency division multiple access includes a signal sequence generation unit configured to generate a synchronization signal sequence to be used for the synchronization signal in a frequency domain; a subcarrier mapping unit configured to divide a transmission band of the synchronization signal into K frequency blocks (K>=2) and map the synchronization signal sequence into one or more subcarriers in the K frequency blocks; a precoding unit configured to generate N precoding vectors to be multiplied by the synchronization signal sequence in the frequency domain and multiply the synchronization signal sequence to be transmitted from an n-th antenna (1<=n<=N) by at least an n-th precoding vector; and a transmission unit configured to transmit the synchronization signal from the N transmission antennas.

Abstract: A base station in a radio communication system in which a radio frame including sub-frames is transmitted/received between a base station and a user equipment using an orthogonal frequency division multiple access scheme. The base station includes: a first multiplexer multiplexing downlink control information in first OFDM symbol positions of the sub-frames in a frequency domain by allocating resources in a manner that the resources are dispersed in the frequency direction in units of resource blocks each constituted by sub-carriers; a second multiplexer multiplexing user information in OFDM symbol positions other than the first OFDM symbol positions of the sub-frames in the frequency domain by allocating resources in a manner that the resources are dispersed in the frequency direction in units of resource blocks; and an inserter inserting a guard time before and after the first OFDM symbol position.

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: To provide a radio base station apparatus and radio communication method capable of performing radio communications using downlink reference signal structures suitable for antenna virtualization, a radio base station apparatus (200) has a plurality of transmission antennas, generates CRSs used in demodulation of at least downlink control information, CQI-RSs generated for each of the transmission antennas used in measurement of channel quality, and DM-RSs generated for each stream used in demodulation of downlink transmission data, and multiplexes the CRSs, CQI-RSs and DM-RSs into a same transmission time unit to transmit from each of the antennas.

Abstract: A modulation device includes a mapping circuit configured to map information bits to signal points on a plurality of concentric rings, when a signal space arrangement in which the number of signal points on all of the plurality of rings is the same is used as a basis, reduce the number of signal points on an innermost ring or a plurality of rings from inner to outer rings from among the plurality of rings, generate a new ring outside the signal space arrangement used as the basis, and arrange, on the generated ring, signal points which achieve the same frequency utilization efficiency as that of the signal space arrangement used as the basis.

Abstract: A modulation device includes a mapping circuit configured to map information bits to signal points on a plurality of concentric rings, when a signal space arrangement in which the number of signal points on all of the plurality of rings is the same is used as a basis, reduce the number of signal points on an innermost ring or a plurality of rings from inner to outer rings from among the plurality of rings, generate a new ring outside the signal space arrangement used as the basis, and arrange, on the generated ring, signal points which achieve the same frequency utilization efficiency as that of the signal space arrangement used as the basis.

Abstract: A base station for transmitting a synchronization signal from N transmission antennas (N>=2) in orthogonal frequency division multiple access includes a signal sequence generation unit configured to generate a synchronization signal sequence to be used for the synchronization signal in a frequency domain; a subcarrier mapping unit configured to divide a transmission band of the synchronization signal into K frequency blocks (K>=2) and map the synchronization signal sequence into one or more subcarriers in the K frequency blocks; a precoding unit configured to generate N precoding vectors to be multiplied by the synchronization signal sequence in the frequency domain and multiply the synchronization signal sequence to be transmitted from an n-th antenna (1<=n<=N) by at least an n-th precoding vector; and a transmission unit configured to transmit the synchronization signal from the N transmission antennas.

Abstract: A base station apparatus is used in a mobile communication system in which at least a shared data channel is transmitted by an orthogonal modulation scheme using an I-channel and a Q-channel. The base station apparatus includes a providing unit providing Acknowledgement/Non-Acknowledgement information indicating whether retransmission of a signal received in uplink is required; a mapping unit mapping a number of multiplexed users of the Acknowledgement/Non-Acknowledgement information to the I-channel or the Q-channel based on a predetermined mapping table; and a reporting unit reporting the Acknowledgement/Non-Acknowledgement information to the respective users. The mapping table indicates that, when the number of the multiplexed users is equal to or less than a predetermined number, the Acknowledgement/Non-Acknowledgement information is associated with the I-channel or the Q-channel, and otherwise, the Acknowledgement/Non-Acknowledgement information is associated with the I-channel and the Q-channel.

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 mobile communications system having a first base station and one or more second base stations is disclosed, wherein the first base station includes a first generator which generates a first known signal for use in common between the first base station and the second base station and a second known signal use specific to each of the first base station and the second base station, and a radio transmitter which wirelessly transmits, to a subordinate terminal apparatus, the first known signal and the second known signal which are generated by the first generator.

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: 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: 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 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: 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 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 transmission apparatus is provided with radio resource assignment means that assigns radio resources to each physical channel according to a type of the physical channel; and transmission means that transmits information to be transmitted by each physical channel using the assigned radio resources.