Abstract: A wireless transmission method for improving the reception characteristic of a preamble. The wireless transmission method allows the patterns of subcarriers (transmitting antenna Tx1: 1, 2, 3, 5, 6, 7, 8, . . . , transmitting antenna Tx2: 4, 9, 10, 12, 13, 14, . . . ) in which preamble sequences are continuously arranged to be changed in a frequency direction. With this, the preamble sequences can be arranged at random subcarrier intervals and, when the autocorrelation values of the preamble sequences are obtained in a time domain, the peak value of the sidelobe becomes small, thereby making it possible to prevent a timing detection error.

Abstract: It is possible to provide a base station device, a mobile station device, a communication system, a channel estimation method, a transmission antenna detection method, and a program which can employ PVS as the SCH transmission diversity method and avoid a side lobe to improve the adjacent cell search performance. When employing the PVS on the frequency axis of the SCH in these, different precoding weights are applied between sub carrier groups so as to correlate a plurality of PSC sequences to a precoding weight matrix and identify the PSC sequence. Moreover, the number of sub carriers to be allocated to sub carrier groups is correlated to the number of transmission antennas so as to detect periodicity of the self-correlation characteristic of a reception SCH signal, thereby identifying the number of transmission antennas.

Abstract: Provided is a MIMO transmission device which can effectively perform a pilot transmission by using a surplus sample generated in a pilot symbol while maintaining the pilot separation accuracy at a reception side. The MIMO transmission device (100) transmits a pilot symbol as follows. That is, in a first pilot transmission symbol section, a transmission section of a pilot signal transmitted from a first transmission antenna is partially overlapped by a pilot transmission section of a second transmission antenna. In a second pilot transmission symbol section, a pilot transmission section of the first transmission antenna is partially overlapped by a pilot transmission section of a third antenna. Among the pilot signals transmitted from the first antenna, the interference portions overlapped by transmission pilot signals from other antennas are different between the first pilot transmission symbol section and the second pilot transmission symbol section.

Abstract: It is possible to provide a novel pilot transmission method which can calculate an accurate channel estimation value, a MIMO transmission device using the pilot transmission method, and a MIMO reception device which performs communication with the MIMO transmission device. The MIMO transmission device (100) includes a cyclic shift processing unit (150) which cyclically shifts a first pilot signal sequence spread by a spread code 1 and second pilot signal sequence spread by a spread code 2 with different shift amounts. The first pilot signal sequence and the second pilot signal sequence which have been cyclically shifted are transmitted from different transmitting antennas at the same pilot transmission symbol section. Thus, by changing the shift amount of the cyclic shift process executed on each pilot signal sequence spread by the respective spread codes, it is possible to improve the pilot separation accuracy at a reception side. This enables more accurate calculation of a channel estimation value.

Abstract: It is possible to provide a novel pilot transmission method which can calculate an accurate channel estimation value, a MIMO transmission device using the pilot transmission method, and a MIMO reception device which communicates with the MIMO transmission device. The MIMO transmission device (100) includes phase adjustment units (130-1, 130-2) which are controlled by a pilot transmission control unit (170) to multiply parallel pilot signals by a phase adjustment coefficient group so as to adjust the pilot signal transmission timing. The pilot transmission control unit (170) differentiates the order of the transmitting antennas in accordance with the pilot transmission timing between an even-number subcarrier group and an odd-number subcarrier group. At a reception side, a path not influenced by the inter-path interference is extracted for each of the combinations of the transmitting antennas and the subcarrier groups.

Abstract: It is possible to provide a transmission control method, a radio communication system, and a radio base station device which can reduce the time required until an inter-cell interference is reduced so as to improve the system throughput. A base station (200) includes: an FFT unit (210) which receives an interference report transmitted by using a common radio resource common to adjacent cells from a plurality of radio terminals (100) existing in different adjacent cells; and an adaptive FFR processing unit (230) which controls adaptive FFR processing in a downstream line of the local cell according to the reception interference report. Thus, by receiving an interference report directly from the radio terminals (100) existing in adjacent cells, it is possible to modify the transmission mode by considering the interference state in the adjacent cells. This eliminates the need of sending a report on a transmission mode modification which has been conventionally sent between adjacent base stations (200).

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: A radio transmitting apparatus and the like for improving the reception error rate characteristic. In this apparatus, a data modulating part (121) modulates a data signal to provide a modulated symbol. A Q-inverting part (125) generates a symbol that corresponds to the modulated symbol provided by the data modulating part (121) and that, when combined with the modulated symbol, becomes a signal having a particular value. A multiplexing part (110) multiplexes the modulated symbol provided by the data modulating part (121) with the corresponding symbol generated by the Q-inverting part (125) to provide a multiplexed signal.

Abstract: There are disclosed a multiantenna radio transmitting apparatus and others wherein control information can be transmitted with enhanced reliability while overheads of transport signals being reduced. This apparatus uses a transmission antenna (Tx) (119) to SDM transmit transport data (1) (CW1) and also uses a transmission antenna (120) to SDM transmit transport data (2) (CW2). In this apparatus, when the transmission quality of the transmission antenna (Tx) (119) is better than that of the transmission antenna (Tx) (120), the control information (2) related to the transport data (2) (CW2) is transmitted in a space division multiplex mode via the transmission antenna (Tx) (119), while the control information (1) related to the transport data (1) (CW1) is transmitted in a diversity mode.

Abstract: A wireless communication method of repetition system and the like for ensuring that when the same data symbols are combined, a diversity gain is achieved. In a step (ST 420), a data symbol placing part (105) decides destination places of respective replicated data symbols (S1-S4) such that the same data symbols are not placed at destination place numbers (7,8) of data symbols that exhibit poor channel estimation precisions. In a step (ST 430), the data symbol placing part (105) places, in accordance with the decision in the foregoing step (ST 420), the four data symbols (S1-S4), which are received from a repetition part (102), in one frame received from a channel estimation error predicting part (104).

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: 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 transmitting/receiving apparatus wherein a decision of performing SDM communication accompanied by a directivity control is correctly performed to improve the transmission efficiency. In the apparatus, a channel estimating part (205) performs channel estimation by use of known symbols included in a received signal. A channel variation deciding part (206) determines a correlation value between a channel estimation result of an immediately preceding process and that of a current process to determines the magnitude of a channel variation, and the determines, based on the magnitude of the channel variation, whether to perform SDM communication accompanied by a directivity control of perform SDM communication not accompanied by the directivity control. When a radio receiving part (107) receives a transmitting weight, a switching part (108) outputs the received transmitting weight to multipliers (103-1 to 103-n).

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

Abstract: Disclosed are a radio communication device and a radio communication method capable of suppressing fluctuations of interference given to an adjacent cell while maintaining a beam gain to a UE of a local cell even when a transmission beam is switched. According to the device and the method, ST201 to ST205 measure CQI using one transmission beam selected from a plurality of transmission beams and a random pattern selected from a plurality of random patterns, for all the transmission beams and for all the combinations of the random patterns. ST206 selects the transmission beam and the random pattern having the maximum CQI among the measured CQI. ST207 transmits the transmission beam and the random pattern selected in ST206 as feedback information to a transmission device (100).

Abstract: Disclosed is a radio transmission device capable of improving a transmission stream error resistance and preventing lowering of a throughput of a communication system. In this device, according to the feedback information from the radio reception device, a repetition control unit (110) decides ranking of each stream, sets a higher repletion rate for a higher stream. This is instructed to repetition units (103-1 to 103-N). According to the repletion rate decided by a repletion control unit (110), the repletion units (103-1 to 103-N) subjects the stream outputted from modulation units (102-1 to 102-N) to a repetition process, and outputs it to transmission RF units (104-1 to 104-N).

Abstract: Provided are a radio communication terminal and a radio communication base station device which are installed in a Multi-User MIMO system even if the ability to suppress interference is low. According to beam combination information fed back from NON-MIMO UE, and beam information and a CQI fed back from another MIMO UE, a scheduler section (102) allocates a space resource to the NON-MIMO UE and allocates the remaining resource to the another MIMO UE. According to the beam combination information, a beam weight generating section (104) generates weight. A transmission beam forming section (105) multiplies each stream outputted from modulation sections (103-1, 103-2) by the weight to form a transmission beam.

Abstract: A wireless communication method realizing a large channel capacity even in an environment of high spatial correlation and improving the reception characteristic, a wireless communication system, and a wireless communication device. Signals (X1, X2) are transmitted between antennas (201-1, 201-2) of a base station (200) and antennas (222-1, 222-2) of a mobile station by a space division multiplexing (SDM) system. On the base station (200) side, if channel information estimated by a channel estimating section (204) is known, a weight calculating section (205) calculates a weight, the transmission signal is multiplied by the weight, and diversity transmission from an antenna (201-3) of the base station (200) is carried out. On the mobile station (220) side, the signal transmitted from the base station (200) is received, a signal separating section (203) carries out signal separation of received signals (Y1, Y2), and thereby the transmitted signals (X1, X2) are restored.

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 hack 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: A radio transmitting apparatus and a radio transmitting method wherein the loss of transmission efficiency is suppressed to improve the reception quality of pilots received by a receiver apparatus. In the present apparatus and method, in a case of transmitting a pilot block at one of two transmission antennas, the areas of data blocks placed immediately before and after the pilot block are reduced, and the CP of the pilot block is expanded by the amount of that reduction. On the other hand, it is arranged that the interval of transmitting the expanded CP and pilot block be an interval of halting the transmission at the other transmission antenna.