Abstract: It is possible to realize reduction of inter-cell interference by an adaptive FFR with a low delay. A terminal (200) includes: an interference condition detection unit (209) which detects an interference condition of other cell to the local cell; a cell identification unit (210) which acquires signals for cell identification of each base station; and a sub-band selection unit (211) which selects a sub-band used for the downstream line transmission to the local station according to the interference condition detected by the interference condition detection unit (209) and the signals for cell identification of each base station obtained by the cell identification unit (210). Thus, the terminal (200) can autonomously select a small sub-band of inter-cell interference and to realize reduction of the inter-cell interference by the adaptive FFR with a low delay.

Abstract: A spatial multiplex number controlling method and others wherein streams can be separated for each of receivers and the transmission efficiency can be improved. In a receiving apparatus, a PER is calculated from a history of CRC test results per stream multiplex number. A reception quality and an offset corresponding to the calculated PER are fed back to a transmitting apparatus. The transmitting apparatus assigns, based on the fed-back reception quality and offset, the streams, thereby controlling the stream multiplex number.

Abstract: In a multiuser MIMO system, entire system throughput achieved during retransmission is significantly enhanced. When an interference signal addressed to another user equipment (UE2) 200b has been demodulated successfully, a user equipment (UE1) 200a holds the demodulated data pertaining to the interference signal, and feeds back ACK information about the UE2 and CQI information achieved after elimination of the interference signal to a radio base station (BS) 100. When the UE2 performs retransmission after ended in a receiving failure and when the UE1 has demodulated the interference signal addressed to the UE2 successfully, the BS changes the distribution of communication resources in such a way that communication resources for the UE2 become larger than those for the UE1.

Abstract: A semiconductor apparatus having a bootstrap-type driver circuit includes a cavity for a SON structure formed below a bootstrap diode Db, and a p-type floating region formed in a n? epitaxial layer between a bootstrap diode Db and a p-type GND region at the ground potential (GND). The p-type floating region extends to the cavity for suppressing the leakage current caused by the holes flowing to the p? substrate in charging an externally attached bootstrap capacitor C1. The semiconductor apparatus which includes a bootstrap-type driver circuit facilitates suppressing the leakage current caused by the holes flowing to the p? substrate, when the bootstrap diode is biased in forward.

Abstract: A wireless communication method and the like for improving the system throughput. The wireless communication method is used in a mobile communication system having a base station apparatus, a relay station apparatus and a mobile station apparatus #1. In a first transmission step, a first transport signal, which includes data addressed to MS #1, is transmitted from BS to RS. In a second transmission step, a second transport signal, which includes a pilot generated by BS, is transmitted from BS. Simultaneously, in the second transmission step, a relay signal, which includes the data addressed to MS #1 and also includes a pilot that is generated by RS and that has a particular orthogonal relationship with the pilot generated by BS, is transmitted from RS to MS #1.

Abstract: Provided is a radio communication method or the like for making compatible an improvement in error rate characteristics and a reduction in delay. The radio communication method is used in a mobile communication system including a mobile station, a relay station and a base station. A transmitted signal containing a signal addressed to the base station is transmitted at first from the mobile station to the relay station. A non-reproduced relay signal obtained in the relay station from the transmitted signal is transmitted from the relay station to the base station. On the basis of the reception result of the non-reproduced relay signal at the base station, a re-transmission request of the transmitted signal is transmitted from the base station. A reproduced relay signal, as obtained from the transmitted signal in the relay station, is transmitted from the relay station to the base station in accordance with the re-transmission request transmitted from the base station.

Abstract: A wireless communication method and the like for improving the system throughput. The wireless communication method is used in a mobile communication system having a base station apparatus (BS), a relay station apparatus (RS) (100) and a mobile station apparatus (MS) #1. In a first transmission step, a first transport signal, which includes data addressed to MS #1, is transmitted from BS to RS (100). In a second transmission step, a second transport signal, which includes a pilot generated by BS, is transmitted from BS. Simultaneously, in the second transmission step, a relay signal, which includes the data addressed to MS #1 and also includes a pilot that is generated by RS (100) and that has a particular orthogonal relationship with the pilot generated by BS, is transmitted from RS (100) to MS #1.

Abstract: Provided is a relay station capable of reducing control information required for allocating a relay transmission channel in a mobile communication system.

Abstract: A MIMO transmitting apparatus that achieves a flexible control in accordance with variation of a propagation environment to reduce the number of retransmissions is disclosed. An intra-code-word interleaver performs an interleave process on bits included in symbols to be simultaneously transmitted from a plurality of transmitting antennas. When performing the intra-code-word interleave process, the intra-code-word interleaver performs the interleave process in accordance with an interleave pattern notified from an interleave pattern table. A counter counts a number of retransmission requests, and outputs the number of retransmission requests to the interleave pattern table. The interleave pattern table stores interleave patterns to be used for the intra-code-word interleave process for the respective numbers of retransmission requests, and notifies the intra-code-word interleaver of an interleave pattern in accordance with the number of retransmission requests.

Abstract: A multicarrier communication apparatus and the like wherein the arithmetic amount required for calculating a reception weight by which a multicarrier signal is to be multiplied is suppressed, while the reception characteristic for the multicarrier signal is improved. In the apparatus, a subcarrier transmission weight generating part (513) generates a transmission weight of each subcarrier, based on channel information of each subcarrier received from a channel information generating part (511) and a reception weight of each subcarrier group received from a subcarrier group reception weight generating part (512). The subcarrier transmission weight generating part (513) inputs the generated transmission weights of the respective subcarriers to the corresponding ones of multipliers (522).

Abstract: A retransmission control scheme and a wireless communication apparatus wherein the efficiency of retransmission control is enhanced to further improve the system throughput. In this wireless communication apparatus (100), an error occurrence factor addressing part (140) receives information related to the error occurrence factor of a transmitted packet or information related to the schemes of forming or transmitting a retransmittal packet corresponding to that error occurrence factor, and switches, based on the received information, the schemes of forming or transmitting the retransmittal packet. In this way, the schemes of forming or transmitting the retransmittal packet can be switched in accordance with the error occurrence factor of the transmitted packet. At the end of receiving the retransmittal packet, therefore, the performing of a decoding processor the like in accordance with that scheme of forming or transmitting can enhance the efficiency of the retransmission control.

Abstract: Provided is a mobile communication system capable of obtaining a diversity effect even when a signal received by a relay station has an error in a corporate relay to which time space encoding is applied. In this mobile communication system, when S1 has no error and S2 has an error, a relay station (1) does not perform relay transmission at time t (Null) and relay-transmits S1* to a base station at time t+T. That is, in this case, the relay station (1) relay-transmits at time t+T only S1 to be transmitted at time t when no error is contained in either S1 or S2. Moreover, when S1 has an error and S2 has no error, the relay station (1) relay-transmits S2 at time t and does not perform relay transmission at time t+T (Null). That is, in this case, the relay station (1) relay-transmits only S2 to be transmitted at time t+T at time t if no error is contained in either S1 or S2.

Abstract: It is possible to realize reduction of inter-cell interference by an adaptive FFR with a low delay. A terminal (200) includes: an interference condition detection unit (209) which detects an interference condition of other cell to the local cell; a cell identification unit (210) which acquires signals for cell identification of each base station; and a sub-band selection unit (211) which selects a sub-band used for the downstream line transmission to the local station according to the interference condition detected by the interference condition detection unit (209) and the signals for cell identification of each base station obtained by the cell identification unit (210). Thus, the terminal (200) can autonomously select a small sub-band of inter-cell interference and to realize reduction of the inter-cell interference by the adaptive FFR with a low delay.

Abstract: Provided is a radio communication method or the like for making compatible an improvement in error rate characteristics and a reduction in delay. The radio communication method is used in a mobile communication system including a mobile station, a relay station and a base station. A transmitted signal containing a signal addressed to the base station is transmitted at first from the mobile station to the relay station. A non-reproduced relay signal obtained in the relay station from the transmitted signal is transmitted from the relay station to the base station. On the basis of the reception result of the non-reproduced relay signal at the base station, a re-transmission request of the transmitted signal is transmitted from the base station. A reproduced relay signal, as obtained from the transmitted signal in the relay station, is transmitted from the relay station to the base station in accordance with the re-transmission request transmitted from the base station.

Abstract: An interleave apparatus and an interleave method for preventing an increase in the number of retransmissions to improve the throughput. In a wireless communication apparatus having the interleave apparatus, a data holding part (1021) two-dimensionally arranges and holds bit sequences. A first index calculating part (1022) sequentially calculates first indexes to be used for reading, in a column direction, the bit sequences arranged in a row direction. A second index calculating part (1023) sequentially calculates second indexes to be used for reversing the order of the upper-order and lower-order bits to be read from the even-numbered columns when the bit sequences are read in accordance with the first indexes. A third index calculating part (1024) sequentially calculates third indexes to be used for reading the bit sequences from a different start position in accordance with the number of retransmissions. A reading part (1025) reads the bit sequences in the order that is in accordance with the third indexes.

Abstract: Provided is a radio communication method or the like for making compatible an improvement in error rate characteristics and a reduction in delay. The radio communication method is used in a mobile communication system (1) including a mobile station (10), a relay station (20) and a base station (30). A transmitted signal containing a signal addressed to the base station (30) is transmitted at first from the mobile station (10) to the relay station (20). A non-reproduced relay signal obtained in the relay station (20) from the transmitted signal is transmitted from the relay station (20) to the base station (30). On the basis of the reception result of the non-reproduced relay signal at the base station (30), a re-transmission request of the transmitted signal is transmitted from the base station (30).

Abstract: A transmitting apparatus, a receiving apparatus and a transmission power control method wherein even in a case of performing a transmission power control of multi-valued modulated symbols, the degradation of reception characteristic and that of network usage efficiency can be avoided. A power control instructing part (204) adjusts, based on an encoding rate and a modulation scheme in a case of applying a power control value, which maximizes the MIMO channel capacity, to each stream, the power control value of a stream, which is the most likely to be affected by a power estimation error, into a reference value, and then applies the adjustment value used for that adjustment to the other streams, that is, the streams that are not likely to be affected by the power estimation error. A power control part (205) performs a transmission power control in accordance with the power control value as adjusted by the power control instructing part (204).

Abstract: A wireless communication system enabling multihop communication while maintaining the system throughput and preventing degradation of the user throughput. In the system, a BS (base station) determines the relaying method (whether an RS performs reproduction relay or nonreproduction relay) of the RS (relaying station) and the MCS of multihop communication according to the reception quality (the line quality among an MS2, the RS, and the BS) of the pilot for nonreproduction relay, the reception quality (the line quality between the RS and the BS) of the pilot 2 for reproduction relay, and the line quality (the line quality between the MS2 and the RS) measured at the RS. The determination result is transmitted as relay information to the RS and to the MS2 (a mobile station (2)) through the RS. The MS2 encodes and modulates the uplink data with the MCS based on the relay information and transmits the data to the RS.

Abstract: Provided is a base station device capable of reducing a DL-CSI feedback amount in a TDD type radio communication system in which a DL bandwidth is different from a UL bandwidth. In this device, a demultiplexing unit (133) separates an UL pilot, a DL-CQI, and a DL-CSI fed back from a plurality of UEs as communication partners; a channel estimation unit (134) performs channel sounding by using a UL pilot from a UE in which a DL channel and a UL channel are allocated by overlapping a part of the bandwidth so as to obtain UL-CSI; a control DL-CSI acquisition unit (135) performs interpolation of DL-CSI by using the DL-CSI of some RB contained in the bandwidth where the DL channel and the UL channel fed back from the UE are not overlapped; and a DL close loop control unit (104) combines the estimated UL-CSI and the interpolated DL-CSI so as to use them as DL-CSI for controlling the DL close loop.

Abstract: A link adaptation method and others wherein feedback information amount can be reduced. According to this method, a receiving apparatus (100) calculates, based on a channel matrix, a capacity (C) and a stream ratio (r) that is a ratio of the reception qualities of streams, and then transmits, as feedback information, the calculated capacity (C) and stream ratio (r) to a transmitting apparatus. In the transmitting apparatus (200), the number of transmittable streams, the modulation scheme and the fed-back capacity (C) are used to calculate the encoding ratio (R) and sequence length (S) of spatial multiplexed symbols. Then, the modulation scheme (M1-Mn) of each stream is decided based on the fed-back stream ratio (r) and the sequence length (S) of spatial multiplexed symbols.