Abstract: An OFDM signal transmission apparatus is provided, which includes a mapping unit configured to map first signals into N subcarriers and second signals into M subcarrier(s) to form an OFDM signal, wherein N is larger than M. The first signals are each indicating a same bit of retransmission information and the second signals are each indicating a same bit of information other than retransmission information. The OFDM signal transmission apparatus further includes a transmitting unit configured to transmit the formed OFDM signal.

Abstract: An OFDM communication apparatus includes a determining section determine a number of known signals for transmission path estimation to be inserted in a transmit signal based on channel quality with respect to a communicating party, and a generating section performs inverse Fourier transform processing on an information signal and the number of known signals for transmission path estimation determined by the determining section and generates a transmit signal for the communicating party. The apparatus achieves both an improvement in demodulated signal error rate characteristics and an improvement in information signal transmission efficiency.

Abstract: Modulation section 201 performs modulation processing on transmission data. Mapping control section 202 controls mapping of the baseband signal onto the subcarriers so that the important information conventionally transmitted by one subcarrier is transmitted by two subcarriers and one of the two subcarriers should be the subcarrier with a carrier frequency signal of frequency 0 which was conventionally not used. IFFT section 203 performs IFFT processing on the modulated transmission data. Transmission section 204 performs transmission processing on the IFFT-processed transmission data and transmits the processed transmission data from antenna 205.

Abstract: In MIMO communication, a communication device is provided that transmits a transfer rate request signal while reducing it and reducing the interference and power consumption when the transfer rate request signal is transmitted substantially without lowering the transmission efficiency. A modulation encoding unit encodes and modulates transmission data transmitted to a communication partner and the transfer rate request signal in the plurality of transmission antennas. A transmission unit and a transmission antenna transmit a signal from the modulation encoding unit. A transmission control unit controls transmission of a signal transmitted from the transmission antenna and transmits a transfer rate request signal of one transmission antenna via the transmission antenna according to a comparison result between a difference of the transfer rate request signal in the respective transmission antenna of the communication partner and a predetermined value.

Abstract: The degree of multiplexing of a code division multiplexed signal transmitted by subcarriers is selected on a subcarrier-by-subcarrier basis. As a result, inter-code interference on the propagation path and degradation on the propagation path are lower for a code division multiplexed signal allocated to subcarriers with a low degree of signal multiplexing (G1) than for transmit signals allocated to subcarriers with a high degree of multiplexing. By this technique, it is possible to prevent degradation of the error rate characteristics of important information without lowering spectral efficiency significantly as compared with the case in which the degree of signal multiplexing is decided uniformly for all subcarriers, and to achieve compatibility between spectral efficiency and error rate characteristics.

Abstract: A transmission device capable of reducing the information amount of channel quality indicators (CQIs) without deteriorating throughput. In the device, an upper bit transmission control unit (104) sets the transmission intervals between upper bits of the CQIs inputted from an S/P conversion unit (103) to be longer than the transmission intervals between lower bits of the CQIs, and a lower bit transmission control unit (105) sets the transmission intervals between the lower bits of the CQIs inputted from the S/P conversion unit (103). Then, a transmission unit (107) transmits the CQI on the basis of the transmission intervals respectively set by the upper bit transmission control unit (104) and the lower bit transmission control unit (105).

Abstract: The degree of multiplexing of a code division multiplexed signal transmitted by subcarriers is selected on a subcarrier-by-subcarrier basis. As a result, inter-code interference on the propagation path and degradation on the propagation path are lower for a code division multiplexed signal allocated to subcarriers with a low degree of signal multiplexing than for transmit signals allocated to subcarriers with a high degree of multiplexing. Thus, it is possible to prevent degradation of the error rate characteristics of important information without lowering spectral efficiency significantly as compared with the case in which the degree of signal multiplexing is decided uniformly for all subcarriers, and to achieve compatibility between spectral efficiency and error rate characteristics.

Abstract: There is provided a communication device capable of transmitting a transfer rate request signal while reducing it and reducing the interference and power consumption when the transfer rate request signal is transmitted substantially without lowering the transmission efficiency in the MIMO communication method. In this device, a modulation encoding unit (125) encodes and modulates transmission data transmitted to a communication partner of the MIMO communication method and the transfer rate request signal in the plurality of transmission antennas. A transmission unit (132) and a transmission antenna (134) transmit a signal from the modulation encoding unit (125).

Abstract: A communication system enabling significant reduction in delay in handover between MAPs without increasing the number of MAPs to install. In the communication system, MAP(101) issues a Router Advertisement to AR(111) to AR(118). Particularly, MAP(101) assigns a plurality of Router Advertisements of a source of care-of address (RCOA) to register with HA to AR(118) of a cell on either side of a boundary of areas for each MAP. MN(107) receives a Router Advertisement transmitted from AR that is a communicating party among AR(119) to AR(126), and using the Router Advertisement, generates care-of addresses, RCOA and LCOA. AR(111) to AR(118) transmit the Router Advertisement RA generated by MAP(101) to MN in communication. Further, AR(111) to AR(118) transmit the care-or-addresses, RCOA and LCOA, issued from MN(107) to MAP(101).

Abstract: A base station (10) performs bi-directional radio communications with terminal station apparatuses using communication frames each having time slots and being composed of a first region with a predetermined open-loop period and a second region with an open-loop period shorter than the open-loop period of the first region. A level detecting section (21) detects a received level of an uplink slot configured in the second region. A transmission diversity section (14) performs diversity transmission on a downlink transmission signal assigned to a downlink slot corresponding to the uplink slot, corresponding to a result of detection of the received level. It is thereby possible to enhance the effect of improving the received quality due to transmission diversity without degrading the transmission efficiency.

Abstract: The transmitting side is equipped with chip steering section 30 that performs a chip steering that shifts the allocation of N×M chip elements upon their respective subcarriers by one chip for every transmission unit in sequence, and the receiving side is equipped with a parallel/serial conversion section and an inverse chip steering section that rearranges the allocation of the chip elements shifted in chip steering section 30 back to original.

Abstract: There is provided a transmission device capable of preventing increase of retransmission information or encoding redundant bit and improving a throughput in a MIMO communication method. In this device, an encoding unit (130) subjects data transmitted from a first transmission antenna (110) and a second transmission antenna (120) each formed by a plurality of antennas, to encoding processing all at once. Modulation units (113, 123) modulate the data encoded by the encoding unit (130) for each of the first and the second transmission antennas (110, 120). Transmission units (115, 125) process the modulated data so that it can be transmitted from the corresponding first and the second antennas (110, 120). A transmission control unit (160) performs transmission control of the data transmitted from the respective antennas (110, 120).

Abstract: A half cut portion is provided with a receiving base for receiving a tube, and a cutter for cutting the tube. The receiving base is provided with a stroke adjusting lever on an upper portion of the receiving base, and the stroke adjusting lever is provided with a cam face in which an amount of projecting is varied by being rotated. The cutter butts to the cam face and a depth of a half cut is set according to a displacement of the amount of projecting of the cam face from the receiving base.

Abstract: A transmission-reception apparatus does not configure ARQ control information from only sequence number, but the transmission-reception apparatus configures the ARQ control information such that the ARQ control information is comprised of one sequence number containing first occurrence of a corresponding packet's error, and bit information representing existence of retransmission requirements about sequence numbers followed on the heels of such the one sequence number.

Abstract: A control section (110) recognizes the type of data included in a transmission signal and outputs a control signal (C1) to an S/P conversion section (101) and a spreading control section (107). The S/P conversion section (101) apportions a specific type of data output from the control section (110) to different transmission systems. Spreading sections (102, 103) carry out spreading processing on the specific type of data output from the S/P conversion section (101) with different spreading codes assigned thereto under the control of the spreading control section (107). The data output from the spreading sections (102, 103) is transmitted by radio through addition sections (104-1, 104-2), transmission sections (105-1, 105-2) and antennas (106-1, 106-2). In this way, it is possible to improve the reception performance on the receiving side for specific data while maintaining the transmission efficiency of an MIMO communication system.

Abstract: In a modulation method such as 8 PSK or a 16 PSK in which a sender device expresses a symbol by using three or more bits, important information is arranged at least at only one of the first and second bits, a receiver device extracts the important information from at least one of the first and second bits of the received signal, and thereby communication control is carried out based on the important information.

Abstract: A control section 101 outputs retransmission information as to whether or not a transmit signal is a retransmission signal, and if a retransmission signal, which (first, second, etc.) retransmission this is, to a selection section 107. An IFFT section 103 performs orthogonal frequency division multiplexing processing of the transmit signal. A GI insertion section 104 inserts a guard interval in the transmit signal. A GI insertion section 105 inserts in the transmit signal a guard interval longer than the guard interval inserted by GI insertion section 104. A GI insertion section 106 inserts in the transmit signal a guard interval longer than the guard intervals inserted by GI insertion section 104 and GI insertion section 105. Based on the retransmission information input from control section 101, selection section 107 selects a transmit signal in which a longer guard interval has been inserted as the number of retransmissions increases.

Abstract: A transmit signal is spread by a plurality of spreading sections 103, 104, 105, and 106, using different spreading codes. A selection section 107 increases the number of spread signals to be output as the number of retransmissions increases. By this means, a retransmission signal spread by means of many spreading codes is code division multiplexed. As a result, retransmission signal error rate characteristics are improved on the receiving side by despreading this code division multiplexed signal using the same plurality of spreading codes as on the transmitting side, and selecting or combining the despreading results with the greatest correlation power thereamong. Also, since the degree of code multiplexing is increased proportionally as the number of retransmissions increases, retransmission signal error rate characteristics can be improved without lowering spectral efficiency unnecessarily.

Abstract: In the case of transmitting a signal of at least three bits in one symbol, when receiving a retransmission request signal from a radio station of a communication partner, a transmission apparatus 10A retransmits only the bits (lower bits) that are susceptible to error, without retransmitting the bits (higher bits) that are not readily susceptible to error and that are obtained by processing in a modulation section 11. A reception apparatus 10B of the communication partner performs error correction processing using the bits (higher bits) and that are stored in memories 16 and 17 and that are not readily susceptible to error, and the bits that are obtained by retransmission and that are susceptible to error (lower bits).

Abstract: An S/P converting section (101) converts input transmission signals A1, A2, B1, B2, . . . , K1, K2 to parallelized data, separated in individual transmission lines. Spreading sections (102, 103) spread the respective data under control of a spread control section (107). Adding sections (104-1, 104-2) multiplex spread data. Transmitting sections (105-1, 105-2) provide radio transmission processing to the multiplexed signals, and transmit the data via antennas (106-1, 106-2) by radio. The spread control section (107) controls the spreading methods in the spreading sections (102, 103) based on channel quality. This makes it possible to improve error rate characteristics of the received signal and as maintain spectrum efficiency when varying data is transmitted from multiple antennas.