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: An OFDM transmitter and an OFDM receiver respectively transmit and receive N (N?2, N is an integer) control symbols. For each control symbol, a guard interval time-domain signal is, for example, identical to a signal obtained by frequency-shifting at least a portion of a useful symbol time-domain signal by an amount different from any other symbol, or to a signal obtained by frequency-shifting one or both of a portion and a span of a useful symbol interval time-domain signal different from any other symbol by a predetermined amount.

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: 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 signal processing device includes: a transmission path estimator that estimates a first transmission path characteristic of a transmission signal using a vertical signal out of vertical and horizontal signals resulting from being received by a vertical polarization antenna and a horizontal polarization antenna; a transmission path estimator that estimates a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculator that calculates a first weight for the vertical signal and a second weight for the horizontal signal, using the first transmission path characteristic and the second transmission path characteristic; and a weighting applier that applies weighted summation to the vertical signal and the horizontal signal using the first weight and the second weight.

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: 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.

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 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: A transmission device that improves data reception quality includes: a weighting synthesizer that generates a first precoded signal and a second precoded signal from a first baseband signal and a second baseband signal, respectively; a phase changer that applies a phase change of i×?? to the second precoded signal; 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 ? radians<??<3?/2 radians. Each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.

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: 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: 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: 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 being included in the multiplexed signal as an undetermined signal component, to generate a first bit likelihood stream; a second demapper that demaps the multiplexed signal, with a first modulated symbol stream being included in the multiplexed signal as an undetermined signal component, to generate a second bit likelihood stream; a first decoder that performs error control decoding on the first bit likelihood stream; and a second decoder that performs error control decoding on the second bit likelihood stream. The multiplexed signal is a signal on which the first modulated symbol stream and the second modulated symbol stream are superposed, the second modulated symbol stream being subjected to conversion in accordance with the first modulated symbol stream in only a first direction.

Abstract: A signal processing device includes: a transmission path estimator that estimates a first transmission path characteristic of a transmission signal using a vertical signal out of vertical and horizontal signals resulting from being received by a vertical polarization antenna and a horizontal polarization antenna; a transmission path estimator that estimates a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculator that calculates a first weight for the vertical signal and a second weight for the horizontal signal, using the first transmission path characteristic and the second transmission path characteristic; and a weighting applier that applies weighted summation to the vertical signal and the horizontal signal using the first weight and the second weight.

Abstract: Embodiments include devices and methods that improves quality in radio transmission/reception using a single-carrier scheme and/or a multi-carrier scheme.