Abstract: This communication device relays a relay signal to be transmitted to and from a first communication device and a second communication device, and is connected to a first apparatus. The communication device transmits the relay signal using a first transmission slot, and also transmits, using a second transmission slot, a signal having been transmitted from the first apparatus, said signal being transmitted within the transmission period of the first transmission slot in a frequency domain different from that of the first transmission slot.

Abstract: All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

Abstract: Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

Abstract: Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a precoding weight by a baseband signal after a first mapping and a baseband signal after a second mapping and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.

Abstract: In a multi-antenna communication system using LDPC codes, a simple method is used to effectively improve the received quality by performing a retransmittal of less data without restricting applicable LDPC codes. In a case of a non-retransmittal, a multi-antenna transmitting apparatus (100) transmits, from two antennas (114A,114B), LDPC encoded data formed by LDPC encoding blocks (102A,102B). In a case of a retransmittal, the multi-antenna transmitting apparatus (100) uses a transmission method, in which the diversity gain is higher than in the previous transmission, to transmit only a part of the LDPC encoded data as previously transmitted. For example, the only the part of the LDPC encoded data to be re-transmitted is transmitted from the single antenna (114A).

Abstract: A controller, which is a communication device, includes: a transfer unit including a function of transferring data received from a first terminal to another communication device via wireless communication; and a determination unit configured to determine whether first information is included in the data received by the transfer unit, the first information indicating that the data is to be multicast. The transfer unit is further configured to multicast the data to a second terminal when the determination unit determines that the first information is included. In the data, the second terminal and the first terminal being different terminals.

Abstract: A signal generation method is used in a transmission device that transmits a plurality of transmission signals from a plurality of antennas at the same frequency and at the same time, in the case where larger power change is performed on a first transmission signal than on a second transmission signal during generation process of the first transmission signal and the second transmission signal, the first transmission signal and the second transmission signal are mapped before the power change such that a minimum Euclidian distance between possible signal points for the first signal is longer than a minimum Euclidian distance between possible signal points for the second signal.

Abstract: This communication system comprises: a first radio-communication device that transmits a plurality of first reference signals with controlled directivity in a time-sharing manner in a first period; and a second radio-communication device that transmits a plurality of second reference signals with controlled directivity to the first radio-communication device in a time-sharing manner in a second period, the second reference signal including information on directivity corresponding to any one of the first reference signals received from the first radio-communication device.

Abstract: Provided are M signal processors that respectively generate modulated signals for M reception apparatuses (where M is an integer equal to 2 or greater), a multiplexing signal processor, and N antenna sections (where N is an integer equal to 1 or greater). When transmitting multiple streams, each of the M signal processors generates two mapped signals, generates first and second precoded signals by precoding the two mapped signals, periodically changes the phase of signal points in the IQ plane with respect to the second precoded signal, outputs the phase-changed signal, and outputs the first precoded signal and the phase-changed second precoded signal as two modulated signals. When transmitting a single stream, each of the M signal processor outputs a single modulated signal. The multiplexing signal processor multiplexes the modulated signals output from the M signal processors, and generates N multiplexed signals. The N antenna sections respectively transmit the N multiplexed signals.

Abstract: A reception device includes: a receiver that receives a multiplexed signal; a first demapper that demaps the multiplexed signal, with a second modulated symbol stream of a second data series being included in the multiplexed signal as an undefined signal component, to generate a first bit likelihood stream of a first data series; a second demapper that demaps the multiplexed signal, with a first modulated symbol stream of the first data series being included in the multiplexed signal as an undefined signal component, to generate a second bit likelihood stream of the second data series; a first decoder that performs error control decoding on the first bit likelihood stream to derive the first data series; and a second decoder that performs error control decoding on the second bit likelihood stream to derive the second data series.

Abstract: A transmission apparatus that (i) generates a Quadrature Phase Shift Keying (QPSK) modulation signal s1(t) by applying a QPSK modulation scheme to a first data sequence, (ii) generates a 16-Quadrature Amplitude Modulation (QAM) modulation signal s2(t) by applying a 16-QAM modulation scheme to a second data sequence, (iii) generates a transmission signal z1(t) and a second transmission signal z2(t) by applying a phase hopping process, a precoding process, and a power adjust process to the QPSK modulation signal s1(t) and the 16-QAM modulation signal s2(t), wherein an average transmission power of the 16-QAM modulation signal s2(t) being the same as an average transmission power of the QPSK modulation signal s1(t), and (iv) transmits the transmission signal z1(t) from a first antenna at a first time and a first frequency and the second transmission signal z2(t) from a second antenna at the first time and the first frequency.

Abstract: Provided is a method for transmitting a broadcasting content and a line content, the broadcasting content and the line content being synchronously displayed, the method including: generating a line parity packet from a plurality of line data packets in each of which the line content is stored; transmitting the line data packet and the line parity packet through a communication line; and transmitting a plurality of broadcasting data packets in each of which the broadcasting content is stored, from a base station using a broadcasting wave, a transfer clock time of the broadcasting content being delayed by a predetermined time compared with a transfer clock time of the line content. At this point, video quality can be improved when the real-time broadcasting program content and the real-time line content are simultaneously displayed.

Abstract: A transmission method for transmitting an emergency warning signal, pertaining to one aspect of the present disclosure, includes: generating control information, the control information including a flag indicating either presence or absence of information related to a region and, when the flag indicates presence, information related to the region; acquiring information related to emergency warning content; and generating the emergency warning signal including the control information and the information related to the emergency warning content. Thus, emergency warning (early warning) information can be transmitted with greater precision.

Abstract: A communication system includes one or more chargers and a server capable of communicating with the one or more chargers. The server obtains first information from a first vehicle via a first charger included in the one or more chargers, during charging of the first vehicle by the first charger, and supplies second information based on the first information to a second vehicle via a second charger included in the one or more chargers, during charging of the second vehicle by the second charger.

Abstract: Useful data is transmitted to a terminal existing in a transportation vehicle. A communication apparatus installed in the transportation vehicle and configured to transmit the data to the terminal existing in the transportation vehicle includes a data selection unit and an illumination unit. The data selection unit acquires location information indicating a location of the transportation vehicle in which the terminal exists and which is traveling. Based on the acquired location information, the data selection unit selects approaching-location data related to a location ahead of a current location of the transportation vehicle in a traveling direction from a plurality of pieces of data related to the location. The illumination unit transmits, as a modulated light signal, a signal comprising the approaching-location data.

Abstract: A terminal (1050) includes a light receiver (151) that receives a light signal emitted by an apparatus (1000), the light signal including an identifier (SSID) of at least one base station (470); a receiver (153) that performs a reception process on the received light signal to output reception data; a data analyzer (155) that selects one base station based on the identifier of the at least one base station that is included in the reception data; and a radio device (453) that establishes a wireless connection with the selected base station (470) by using the identifier of the base station (470) and wirelessly communicates with the base station (470).

Abstract: Disclosed is a precoding method comprising the steps of: generating a first coded block and a second coded block with use of a predetermined error correction block coding scheme; generating a first precoded signal z1 and a second precoded signal z2 by performing a precoding process, which corresponds to a matrix selected from among the N matrices F[i], on a first baseband signal s1 generated from the first coded block and a second baseband signal s2 generated from the second coded block, respectively; the first precoded signal z1 and the second precoded signal z2 satisfying (z1, z2)T=F[i] (s1, s2)T; and changing both of or one of a power of the first precoded signal z1 and a power of the second precoded signal z2, such that an average power of the first precoded signal z1 is less than an average power of the second precoded signal z2.

Abstract: A controller, which is a communication device, includes: a transfer unit including a function of transferring data received from a first terminal to another communication device via wireless communication; and a determination unit configured to determine whether first information is included in the data received by the transfer unit, the first information indicating that the data is to be multicast. The transfer unit is further configured to multicast the data to a second terminal when the determination unit determines that the first information is included in the data, the second terminal and the first terminal being different terminals.

Abstract: All data symbols used in data transmission of a modulated signal are precoded by switching between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol along the frequency axis and the time axis all differ. A modulated signal with such data symbols arranged therein is transmitted.

Abstract: Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.