Abstract: Disclosed are a retransmission method, a base station, and a user device in a multicast system. In order to reduce uplink signaling resource, a new MNI (Multiple NACK Indicator) message is added to an uplink common feedback channel in an existing E-MBMS system. The MNI message enables decision of an XOR retransmission group which satisfies the XOR retransmission condition. As compared to a conventional XOR retransmission, the number of uplink signalings does not depend on the number of receivers. That is, when a plenty of receptions are present, it is possible to significantly reduce uplink signalings.

Abstract: Provided is a wireless communication apparatus wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. In the wireless communication apparatus (100), an encoding section (101) encodes and outputs transmitting data (bit string) to a bit converting section (102), and the bit converting section (102) converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into ‘1’ or ‘0’ and outputs it to a modulating section (103). The modulating section (103) modulates the bit string inputted from the bit converting section (102) by using a single modulation mapper and a plurality of data symbols are generated.

Abstract: A wireless relay station apparatus for enabling a mobile station and a base station to reliably receive network coding data and to provide sufficient reception performance is provided. (1) A repeater divides data X received from a mobile station into important data and non-important data and divides data Y received from eNB into important data and non-important data. Next, (2) the repeater places the data so that important data Sx for the mobile station and important data Sy for the eNB do not overlap, XORs (exclusive ORs) them, and generates network coding data X (X) Y. (3) The repeater applies downlink propagation inverse characteristic H1?1 to important data portion Px (X) Sy for the mobile station and on the other hand, applies uplink propagation inverse characteristic H0?1 to important data portion Sx (X) Py for the eNB in the network coding data X (X) Y for transmission.

Abstract: It is possible to improve the CQI reception performance even when a delay is caused in a propagation path, a transmission timing error is caused, or a residual interference is generated between cyclic shift amounts of different ZC sequences. For the second symbol and the sixth symbol of the ACK/NACK signal which are multiplexed by RS of CQI, (+, +) or (?, ?) is applied to a partial sequence of the Walsh sequence. For RS of CQI transmitted from a mobile station, + is added as an RS phase of the second symbol and ? is added as an RS phase of the sixth symbol. A base station (100) receives multiplexed signals of ACK/NACK signals and CQI signals transmitted from a plurality of mobile stations. An RS synthesis unit (119) performs synthesis by aligning the RS phase of CQI.

Abstract: When power scaling is applied to multi-user MIMO, a reduction in transmission rate is suppressed and transmission efficiency is improved. When signals are transmitted through spatial multiplexing from a wireless base station 11 to a plurality of pieces of user equipment 12 and 13, notification of a transmission parameter (MCS) of the distant user equipment (UE-B) 13 is provided as control information to the adjacent user equipment (UE-A) 12. The user equipment 12 calculates, based on the received control information, a reception quality (CQI) after cancellation of a signal serving as an interference signal and destined for the other user equipment 13, and feeds back the calculated result to the wireless base station 11.

Abstract: Disclosed is a frequency band allocation method which reduces PAPR (peak to average power ratio) when performing a single carrier transmission in the uplink line of an LTE+ (LTE Advanced) system in a system using both of an LTE (Long Term Evolution) system and the LTE+ system. In the frequency band allocation method, a UL band for the LTE is arranged adjacently in a lower frequency band than the UL band for the LTE+. With this arrangement, it is possible to prevent division of the band for the LTE+ by the uplink line control channel (such as PUCCH) transmitted by an LTE mobile station and to allocate a wide band continuously with the LTE+ mobile station. Especially when the LTE+ mobile station performs a single carrier transmission with the uplink line, the PAPR can be reduced since it is possible to allocate a band continuous with the single carrier signal.

Abstract: A radio receiver apparatus that can effectively utilize GI to improve the reception quality. In this apparatus, a data extracting part extracts a data portion of a direct wave from a signal subjected to a radio reception process by a received RF part. A GI extracting part extracts, from the signal subjected to the radio reception process by the received RF part, GI having a length determined by an extracted GI length deciding part. The extracted GI is adjusted by a data position adjusting part such that its rear end coincides with the read end of the extracted data portion. A combining part combines the extracted data portion with the GI the data position of which has been adjusted. The combined signal is then supplied to a frequency axis equalizing part, which equalizes the signal distortions of the combined signal on the frequency axis.

Abstract: To improve throughput by reducing the resource used for transmitting a parameter relating to retransmission control and decreasing overhead of retransmission control signaling. Where a retransmission control method is employed with adaptive MCS control in which the encoding rate can be changed, the scheduling section sets the MCS in accordance with CQI notified from the communication counterpart apparatus. When transmission data is encoded, the RV parameter bit-number setting section sets the number of bits used for signaling the RV parameter to decrease as the encoding rate of the first transmission is decreased and sets the RV parameter based on the number of bits. For example, in a case where the encoding rate R is R>?, two bits are set. In a case where the encoding rate ?<R??, one bit is set. On the other hand, in a case where R??, zero bits is set.

Abstract: A radio communication device capable of randomizing both inter-cell interference and intra-cell interference. In this device, a spreading section primarily spreads a response signal in a ZAC sequence set by a control unit. A spreading section secondarily spreads the primarily spread response signal in a block-wise spreading code sequence set by the control unit. The control unit controls the cyclic shift amount of the ZAC sequence used for the primary spreading in the spreading section and the block-wise spreading code sequence used for the secondary spreading in the spreading section according to a set hopping pattern. The hopping pattern set by the control unit is made up of two hierarchies. An LB-based hopping pattern different for each cell is defined in the first hierarchy in order to randomize the inter-cell interference. A hopping pattern different for each mobile station is defined in the second hierarchy to randomize the intra-cell interference.

Abstract: In DFT-s-OFDM, disclosed are a wireless transmission apparatus and wireless transmission method whereby freedom of allocation of frequencies is secured, while increases of CM are avoided. An SD number determination unit (152) determines an SD number based on the channel quality information of a mobile station and a threshold value that is set by a threshold value setting unit (151). A transmission bandwidth determination unit (153) determines the transmission bandwidth necessary for transmission of the transmission data. An allocation commencement position determination unit (154) determines the position for commencement of allocation of transmission data. If the SD number is equal to or more than the threshold value, a divided bandwidth determination unit (155) sets all the divided bandwidths to equal values and a frequency interval determination unit (156) sets all the frequency intervals to equal values.

Abstract: A repeater capable of improving the data decoding performance at a base station while achieving sharing of processing for data exchange between repeaters and initial data transmission to the base station (eNB) is provided. A repeater 100 which cooperates with another repeater 200 to relay data to a base station 300 includes a storage section 113 which stores first data of the local apparatus, a receiving section 101 which receives at least a portion of the second data of another repeater 200, an interleave section 111 which applies interleaving to at least a portion of the first data and the second data in accordance with a difference in propagation quality between the base station 300 and each of the repeaters, and segments data after interleaving, and a transmitting section 116 which, if data after interleaving is segmented, transmits segmented data to the base station.

Abstract: It is possible to provide a radio communication system, a radio base station device, and a radio terminal device capable of reducing the power consumption in a radio terminal device without thinning pilot signals used for measuring upstream line quality. In the radio base station device (100) used in a radio communication system using different frequency bands for the upstream line and the downstream line, an upstream line pilot generation unit (115) forms a CQI measuring pilot signal and an upstream line RF unit (105) transmits the communication quality measuring pilot signal by using the upstream line use frequency band in the upstream line pilot transmission section. Thus, the upstream communication quality measuring pilot signal used by the radio base station device (100) to measure the line quality is transmitted by using the upstream line frequency band and accordingly, it is possible to reduce the power consumption in the radio terminal device.

Abstract: Disclosed is a wireless communication base station apparatus capable of preventing degradation of throughput of LTE terminals, even when both LTE terminals and LTE+ terminals are present together. In this apparatus, a CCE allocation section (105) allocates the characteristic cell reference signals, which are employed solely by LTE+ terminals, to some CCEs from a plurality of CCEs to which a control channel for LTE terminal use or a control channel for LTE+ terminal use can be allocated. In the case of symbols that are mapped to antennas (113-5) to (113-8), an arrangement section (109) arranges the characteristic cell reference signals that are employed solely by LTE+ terminals in resource elements corresponding to CCEs to which a characteristic cell RS has been allocated that is used solely by an LTE+ terminal, based on position information that is input from an interleaving section (106).

Abstract: In order to reduce interference between cells through hopping and use frequencies in a good propagation situation, a scheduler section carries out scheduling for determining to which user data should be sent using CQI from each communication terminal apparatus, selects a user signal to be sent in the next frame and determines in which subcarrier block the data should be sent. Au MCS decision section selects a modulation scheme and coding method from the CQI of the selected user signal. A subcarrier block selection section selects a subcarrier block instructed by the scheduler section 102 for each user signal. For the respective subcarrier blocks, FH sequence selection sections select hopping patterns. A subcarrier mapping section maps the user signal and control data to subcarriers according to the selected hopping pattern.

Abstract: Provided is a radio communication device which can separate propagation paths of antenna ports and improve a channel estimation accuracy even when using virtual antennas. The device includes: a mapping unit (103) which maps a data signal after modulation to a virtual antenna (0) and a virtual antenna (1); a phase inversion unit (104) which inverts the phase of S0 transmitted from an antenna port (2) in synchronization with a phase inversion unit (105) between the odd-number slot and the even-number slot; the phase inversion unit (105) which inverts the phase of R0 transmitted from the antenna port (2); a phase inversion unit (113) which inverts the phase of S1 transmitted from an antenna port (3) in synchronization with a phase inversion unit (114); and the phase inversion unit (114) which inverts the phase of R1 transmitted from an antenna port (3).

Abstract: A radio communication device capable of randomizing both inter-cell interference and intra-cell interference. In this device, a spreading section primarily spreads a response signal in a ZAC sequence set by a control unit. A spreading section secondarily spreads the primarily spread response signal in a block-wise spreading code sequence set by the control unit. The control unit controls the cyclic shift amount of the ZAC sequence used for the primary spreading in the spreading section and the block-wise spreading code sequence used for the secondary spreading in the spreading section according to a set hopping pattern. The hopping pattern set by the control unit is made up of two hierarchies. An LB-based hopping pattern different for each cell is defined in the first hierarchy in order to randomize the inter-cell interference. A hopping pattern different for each mobile station is defined in the second hierarchy to randomize the intra-cell interference.

Abstract: To improve throughput by reducing the resource used for transmitting a parameter relating to retransmission control and decreasing the overhead of retransmission control signaling. In a case where a retransmission control method is employed in consideration of adaptive MCS control in which the encoding rate can be changed, the scheduling section sets the MCS in accordance with CQI notified from the communication counterpart apparatus. When transmission data is encoded, the RV parameter bit-number setting section sets the number of bits used for signaling the RV parameter to decrease as the encoding rate of the first transmission is decreased and sets the RV parameter based on the number of bits. For example, in a case where the encoding rate R is R>2/3, two bits are set. In a case where the encoding rate 1/3<R?2/3, one bit is set. On the other hand, in a case where R?1/3, zero bits is set.

Abstract: It is possible to improve the CQI reception performance even when a delay is caused in a propagation path, a transmission timing error is caused, or a residual interference is generated between cyclic shift amounts of different ZC sequences. For the second symbol and the sixth symbol of the ACK/NACK signal which are multiplexed by RS of CQI, (+, +) or (?, ?) is applied to a partial sequence of the Walsh sequence. For RS of CQI transmitted from a mobile station, + is added as an RS phase of the second symbol and ? is added as an RS phase of the sixth symbol. A base station (100) receives multiplexed signals of ACK/NACK signals and CQI signals transmitted from a plurality of mobile stations. An RS synthesis unit (119) performs synthesis by aligning the RS phase of CQI.

Abstract: A radio transmission device and a radio communication method employ sequence length decision units which hold a correspondence in which one basic sequence length is set for a plurality of transmission bandwidths. The sequence length decision units acquire transmission bandwidth information and decide a sequence length corresponding to the acquired transmission bandwidth information. A decision is made as to which of the cyclic extension process or the truncation process is to be executed on a Zadoff-Chu sequence according to the sizes of the acquired transmission bandwidth information and the basic sequence length. Then, a difference between the transmission bandwidth and the basic sequence length, i.e., the number of possible cyclic extension/truncation symbols, is obtained.

Abstract: A radio transmission apparatus and a radio transmission method suppress lowering of the throughput caused by switching between the single carrier communication method and the multi-carrier communication method while suppressing increase in the signaling amount. A PHR threshold value setter sets a threshold value at a position greater by a predetermined value than the PHR at which the throughput performance of the SC-FDMA coincides with that of the OFDMA. A trigger signal transmission judger judges that a mobile station transmits a trigger signal for switching from the OFDMA to the SC-FDMA if the PHR in the OFDMA communication method is lower than the threshold value.