Abstract: An indicator in a master AP from among a plurality of APs obtains communication quality of communication with an AP which is a communication partner. In the case where the obtained communication quality is less than a threshold, the indicator causes the plurality of APs including the master AP to perform cooperative operation to transmit data. In the case where the obtained communication quality is not less than the threshold, the indicator causes the plurality of APs including the master AP to stop the cooperative operation.

Abstract: By a transmission method according to one aspect of the present disclosure, in a broadcasting system that generates a first broadcasting signal and a second broadcasting signal by performing multi-antenna encoding on program data, and wirelessly transmits a first broadcasting signal and a second broadcasting signal, a first transmit station transmits the first broadcasting signal, a second transmit station transmits the second broadcasting signal, the first transmit station and the second transmit station transmit the first broadcasting signal and the second broadcasting signal to an overlapping area at an identical time using an overlapping frequency band, polarized wave transmitted from the first transmit station differs from polarized wave transmitted from the second transmit station, and arrangement of the first transmit station differs from arrangement of the second transmit station.

Abstract: Disclosed is a relay method including: receiving, as input, respective reception signals by two receive antennas, the reception signals each including a reception signal resulting from multiplexing respective transmission signals transmitted by two transmission antennas in a first frequency band; performing frequency conversion on the reception signal received by one of the receive antennas so as to obtain a signal of a third frequency band; and performing frequency multiplexing on the signal having the third frequency band and the reception signal received by the other of the receive antennas.

Abstract: A transmission method of simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals. One of signal generation processing in which phase change is performed and signal generation processing in which phase change is not performed is selectable, thereby improving general versatility in signal generation.

Abstract: One coding method of a plurality of coding methods including at least a first coding method and a second coding method is selected, an information sequence is encoded by using the selected coding method, and an encoded sequence obtained by performing predetermined processing on the information sequence is modulated and transmitted. The first coding method is a coding method having a first coding rate, for generating a first encoded sequence by performing puncturing processing on a generated first codeword by using a first parity check matrix. The second coding method is a coding method having a second coding rate, for generating a second encoded sequence by performing puncturing processing on a generated second codeword by using a second parity check matrix that is different from the first parity check matrix, the second coding rate after the puncturing process being different from the first coding rate.

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: A transmission device that improves data reception quality includes: a first pilot inserter that inserts a pilot signal into a first precoded signal; a phase changer that applies a phase change of i×?? to the second precoded signal, where i is a symbol number and an integer that is greater than or equal to 0; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. ?? satisfies ?/2 radians<??<? radians or a radians<??<3?/2 radians. When the communications scheme is an OFDM scheme, the phase changer and the phase changer apply a phase change, and when the communications scheme is a single-carrier scheme, do not apply a phase change.

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: An encoder outputs a first bit sequence having N bits. A mapper generates a first complex signal s1 and a second complex signal s2 with use of bit sequence having X+Y bits included in an input second bit sequence, where X indicates the number of bits used to generate the first complex signal s1, and Y indicates the number of bits used to generate the second complex signal s2. A bit length adjuster is provided after the encoder, and performs bit length adjustment on the first bit sequence such that the second bit sequence has a bit length that is a multiple of X+Y, and outputs the first bit sequence after the bit length adjustment as the second bit sequence. As a result, a problem between a codeword length of a block code and the number of bits necessary to perform mapping by a set of modulation schemes is solved.

Abstract: A transmission device that performs multiple-input multiple-output (MIMO) transmission of transmit data using a plurality of fundamental bands. The transmission device includes an error correction coding unit, a mapping unit, and a MIMO coding unit. The error correction coding unit, for each data block of predefined length, performs error correction coding and thereby generates an error correction coded frame. The mapping unit maps each predefined number of bits in the error correction coded frame to a corresponding symbol and thereby generates an error correction coded block. The MIMO coding unit performs MIMO coding with respect to the error correction coded block. Components of data included in the error correction coded block are allocated to at least two of the fundamental bands and transmitted.

Abstract: Disclosed is a relay method including: receiving, as input, respective reception signals by two receive antennas, the reception signals each including a reception signal resulting from multiplexing respective transmission signals transmitted by two transmission antennas in a first frequency band; performing frequency conversion on the reception signal received by one of the receive antennas so as to obtain a signal of a third frequency band; and performing frequency multiplexing on the signal having the third frequency band and the reception signal received by the other of the receive antennas.

Abstract: When transmitting signals from a plurality of base stations (broadcasting stations), the base stations include at least a first base station having a first antenna with a first polarization and a second base station having a second antenna with a second polarization that is different from the first polarization. Then, when the first base station transmits a signal from the first antenna having the first polarization, the second base station transmits the same signal as the first antenna of the first base station from a second antenna having the second polarization, at the same time.

Abstract: One coding scheme is selected from a plurality of coding schemes, an information sequence is encoded by using the selected coding scheme, and an obtained encoded sequence is modulated to obtain a modulated signal. The obtained modulated signal is subjected to a phase change and is transmitted. The plurality of coding schemes include at least a first coding scheme and a second coding scheme. The first coding scheme is a coding scheme with a first coding rate for forming a generated first codeword as a first encoded sequence by using a first parity check matrix. The second coding scheme is a coding scheme with a second coding rate obtained after puncturing processing, for generating a second encoded sequence by performing the puncturing processing on a generated second codeword by using a second parity check matrix different from the first parity check matrix. The number of bits of the first encoded sequence is equal to the number of bits of the second encoded sequence.

Abstract: A signal generation method includes phase-changing baseband signals with respective phase changing patterns to generate respective phase-changed signals, each of the phase changing patterns being different from each other, and inverse-fast-Fourier-transforming the phase-changed signals to respective orthogonal frequency division multiplexing (OFDM) transmission signals. Each phase changing pattern has N candidates for an amount of change in a phase, N being an integer greater than two, and each candidate is periodically selected from the N candidates based on subcarriers of the respective OFDM transmission signals, a phase of the respective baseband signals being changed by the each candidate.

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 transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Abstract: Provided is control information related to polarizations of antennas for MISO communication. The control signal generator generates polarization information indicating whether antennas used for transmission by MISO have only a first polarization or have a second polarization as well as the first polarization. With this structure, the present invention allows for the use of combinations of SISO, MISO and MIMO, taking the polarization of antennas. Furthermore, the present invention enables the receiver to reduce the power consumption.

Abstract: Provided is a transmission method that improves data reception quality in radio transmission using a single-carrier scheme and/or a multi-carrier scheme. The transmission method includes: generating a plurality of first modulated signals s1(i) and second modulated signals s2(i) from transmission data, the plurality of first modulated signals s1(i) being signals generated using a QPSK modulation scheme, and the plurality of second modulated signals s2(i) being signals generated using 16QAM modulation; generating, from the plurality of first modulated signals s1(i) and the plurality of second modulated signals s2(i), a plurality of first signal-processed signals z1(i) and a plurality of second signal-processed signals z2(i) which satisfy a predetermined equation; and transmitting the plurality of first signal-processed signals z1(i) and the plurality of second signal-processed signals z2(i) using a plurality of antennas.

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: A transmitting method includes: configuring a frame using a plurality of orthogonal frequency-division multiplexing (OFDM) symbols, by allocating a plurality of transmission data to a plurality of areas; and transmitting the frame. The plurality of areas are each identified by at least one time resource among resources and at least one frequency resource among frequency resources. The frame includes a first period in which a preamble is transmitted, and a second period in which the plurality of transmission data are transmitted by at least one of time division and frequency division. The second period includes a first area, and the first area includes a data symbol generated from first transmission data, a data symbol generated from second transmission data and subsequent to the data symbol generated from the first transmission data, and a dummy symbol subsequent to the data symbol generated from the second transmission data.