Abstract: A receiving method for receiving a plurality of carriers and generating one or a plurality of streams. The method includes a first demodulating step of processing a first transmission signal and generating a first demodulation output; a second demodulating step of processing a second transmission signal different from the first transmission signal and generating a second demodulation output; a combining step of generating one stream based on the first demodulation output and the second demodulation output; a selecting step of selecting one among the first demodulation output and the one stream, and generating a selected stream; and a back-end processing step of generating an output for a display from the selected stream and the second demodulation output. In the selecting step, the first demodulation output is selected in a receiving mode in single channel transmission, and the one stream is selected in a receiving mode in multiple channel transmission.

Abstract: A receiving method for receiving a plurality of carriers and generating one or a plurality of streams. The method includes a first demodulating step of processing a first transmission signal and generating a first demodulation output; a second demodulating step of processing a second transmission signal different from the first transmission signal and generating a second demodulation output; a combining step of generating one stream based on the first demodulation output and the second demodulation output; a selecting step of selecting one among the first demodulation output and the one stream, and generating a selected stream; and a back-end processing step of generating an output for a display from the selected stream and the second demodulation output. In the selecting step, the first demodulation output is selected in a receiving mode in single channel transmission, and the one stream is selected in a receiving mode in multiple channel transmission.

Abstract: A receiving system of the present disclosure includes: a plurality of demodulators; an add-on generating one stream based on an output from each of the demodulators; a selector selecting and outputting one among an output from one of the demodulators, namely the demodulator, and the one stream from the add-on; and a back-end processor generating an output for a display based on an output from the selector and the other demodulators, namely the demodulators. The selector selects an output from the demodulator in a single channel transmission mode, and selects the stream from the add-on in a multiple channel transmission mode.

Abstract: A receiving system of the present disclosure includes: a plurality of demodulators; an add-on generating one stream based on an output from each of the demodulators; a selector selecting and outputting one among an output from one of the demodulators, namely the demodulator, and the one stream from the add-on; and a back-end processor generating an output for a display based on an output from the selector and the other demodulators, namely the demodulators. The selector selects an output from the demodulator in a single channel transmission mode, and selects the stream from the add-on in a multiple channel transmission mode.

Abstract: Provided is an OFDM reception apparatus that can reduce, even in an environment where the influence of noises is strong, this influence of the noises, thereby improving the precision of detecting a carrier frequency error. In this apparatus, a filtering unit (151) receives received signals each including a short preamble (STF) in which a plurality of pilot subcarriers are intermittently arranged in the frequency domain and repeatedly arranged in the time domain, and the filtering unit (151) attenuates the frequency components between respective two adjacent ones of the plurality of pilot subcarriers in the frequency domain. A correction unit (154) corrects a carrier frequency error of the received signal on the basis of the signals of the plurality of pilot subcarriers having passed through the filtering unit (151).

Abstract: A preamble generating unit generates first and second synchronization preambles having different numbers of subcarriers. A transmission signal generating unit generates an OFDM transmission signal through time-division multiplexing by using the generated first and second synchronization preambles. A transmission RF unit converts the generated OFDM transmission signal into a radio-frequency OFDM signal and transmits the radio-frequency OFDM signal. The preamble generating unit adds a predetermined dummy period between the first synchronization preamble and the second synchronization preamble.

Abstract: An OFDM receiver apparatus (100) receives a signal that includes an STF having a plurality of pilot subcarriers and a plurality of null subcarriers that are alternately arranged at predetermined frequency intervals in a transmission band and that includes a data part that is time-multiplexed with the STF. A null carrier extraction unit (151) extracts a plurality of null subcarrier frequency signals from the received signal. A power calculation unit (152) detects, based on the levels of the extracted signals, the interference levels of the plurality of subcarriers in the transmission band. A soft decision unit (112) uses the reliability of the plurality of subcarriers, which is calculated based on the detected interference levels, to perform a soft decision of a demodulated signal of the received data part. An error correction unit (113) performs, based on the result of the soft decision, an error correction, thereby reconstructing the data.

Abstract: An interfering wave is detected using, in a received signal including a preamble and a control signal field, a plurality of symbols including a symbol configuring the preamble and a symbol configuring the control signal field. The received signal has one of a plurality of transmission formats that use at least either a first frequency band or a second frequency band. In a signal quality detector, a symbol differential calculator calculates, in each of the first frequency band and the second frequency band, differences between a certain number of symbols adjacent to one another at predetermined positions in a time domain among the plurality of symbols. A square operator performs square operations on results of the calculation of differences. An interference determiner determines, using results of the square operations, whether each of the first frequency band and the second frequency band includes an interfering wave.

Abstract: A tuner receives a received signal using one of a plurality of transmission formats that use at least one of either a first frequency or a second frequency band. A determination unit determines the transmission format being used in the received signal from among the plurality of transmission formats. In the determination unit, a pattern matching unit stores in advance a plurality of patterns respectively expressing a received waveform of a preamble in each of the plurality of transmission formats, conducts a pattern matching process between the received signal and the each of the plurality of patterns, and obtains a correlation value. A transmission mode determination unit determines the transmission format being used in the received signal on the basis of the correlation value.

Abstract: A tuner receives a received signal using one of a plurality of transmission formats that use at least one of either a first frequency or a second frequency band. A determination unit determines the transmission format being used in the received signal from among the plurality of transmission formats. In the determination unit, a pattern matching unit stores in advance a plurality of patterns respectively expressing a received waveform of a preamble in each of the plurality of transmission formats, conducts a pattern matching process between the received signal and the each of the plurality of patterns, and obtains a correlation value. A transmission mode determination unit determines the transmission format being used in the received signal on the basis of the correlation value.

Abstract: A tuner receives a received signal using one of a plurality of transmission formats that use at least one of either a first frequency or a second frequency band. A determination unit determines the transmission format being used in the received signal from among the plurality of transmission formats. In the determination unit, a pattern matching unit stores in advance a plurality of patterns respectively expressing a received waveform of a preamble in each of the plurality of transmission formats, conducts a pattern matching process between the received signal and the each of the plurality of patterns, and obtains a correlation value. A transmission mode determination unit determines the transmission format being used in the received signal on the basis of the correlation value.

Abstract: A tuner receives a received signal using one of a plurality of transmission formats that use at least one of either a first frequency or a second frequency band. A determination unit determines the transmission format being used in the received signal from among the plurality of transmission formats. In the determination unit, a pattern matching unit stores in advance a plurality of patterns respectively expressing a received waveform of a preamble in each of the plurality of transmission formats, conducts a pattern matching process between the received signal and the each of the plurality of patterns, and obtains a correlation value. A transmission mode determination unit determines the transmission format being used in the received signal on the basis of the correlation value.

Abstract: An OFDM receiver apparatus (100) receives a signal that includes an STF having a plurality of pilot subcarriers and a plurality of null subcarriers that are alternately arranged at predetermined frequency intervals in a transmission band and that includes a data part that is time-multiplexed with the STF. A null carrier extraction unit (151) extracts a plurality of null subcarrier frequency signals from the received signal. A power calculation unit (152) detects, based on the levels of the extracted signals, the interference levels of the plurality of subcarriers in the transmission band. A soft decision unit (112) uses the reliability of the plurality of subcarriers, which is calculated based on the detected interference levels, to perform a soft decision of a demodulated signal of the received data part. An error correction unit (113) performs, based on the result of the soft decision, an error correction, thereby reconstructing the data.

Abstract: Provided is an OFDM reception apparatus that can reduce, even in an environment where the influence of noises is strong, this influence of the noises, thereby improving the precision of detecting a carrier frequency error. In this apparatus, a filtering unit (151) receives received signals each including a short preamble (STF) in which a plurality of pilot subcarriers are intermittently arranged in the frequency domain and repeatedly arranged in the time domain, and the filtering unit (151) attenuates the frequency components between respective two adjacent ones of the plurality of pilot subcarriers in the frequency domain. A correction unit (154) corrects a carrier frequency error of the received signal on the basis of the signals of the plurality of pilot subcarriers having passed through the filtering unit (151).

Abstract: A tuner receives a received signal using one of a plurality of transmission formats that use at least one of either a first frequency or a second frequency band. A determination unit determines the transmission format being used in the received signal from among the plurality of transmission formats. In the determination unit, a pattern matching unit stores in advance a plurality of patterns respectively expressing a received waveform of a preamble in each of the plurality of transmission formats, conducts a pattern matching process between the received signal and the each of the plurality of patterns, and obtains a correlation value. A transmission mode determination unit determines the transmission format being used in the received signal on the basis of the correlation value.

Abstract: A preamble generating unit generates first and second synchronization preambles having different numbers of subcarriers. A transmission signal generating unit generates an OFDM transmission signal through time-division multiplexing by using the generated first and second synchronization preambles. A transmission RF unit converts the generated OFDM transmission signal into a radio-frequency OFDM signal and transmits the radio-frequency OFDM signal. The preamble generating unit adds a predetermined dummy period between the first synchronization preamble and the second synchronization preamble.

Abstract: A tuner receives a received signal using one of a plurality of transmission formats that use at least one of either a first frequency or a second frequency band. A determination unit determines the transmission format being used in the received signal from among the plurality of transmission formats. In the determination unit, a pattern matching unit stores in advance a plurality of patterns respectively expressing a received waveform of a preamble in each of the plurality of transmission formats, conducts a pattern matching process between the received signal and the each of the plurality of patterns, and obtains a correlation value. A transmission mode determination unit determines the transmission format being used in the received signal on the basis of the correlation value.

Abstract: An interfering wave is detected using, in a received signal including a preamble and a control signal field, a plurality of symbols including a symbol configuring the preamble and a symbol configuring the control signal field. The received signal has one of a plurality of transmission formats that use at least either a first frequency band or a second frequency band. In a signal quality detector, a symbol differential calculator calculates, in each of the first frequency band and the second frequency band, differences between a certain number of symbols adjacent to one another at predetermined positions in a time domain among the plurality of symbols. A square operator performs square operations on results of the calculation of differences. An interference determiner determines, using results of the square operations, whether each of the first frequency band and the second frequency band includes an interfering wave.

Abstract: A communication apparatus (1) is provided with: a calculating unit (2) operable to calculate a correlation value of a predetermined pattern included in a receiving signal; a generating unit (3) operable to generate a synchronization signal according to the correlation value; a measuring unit (4) operable to measure a predetermined cycle according to the synchronization signal; and a control unit (5) operable to control power consumption of at least one of the calculating unit (2) and the generating unit (3). The measuring unit (4) includes the synchronization signal internally on a time axis, and defines a first period having a predetermined length and a second period not overlapping with the first period. The control unit (5) controls power consumption by operating an electronic signal in at least one of the calculating unit (2) and the generating unit (3) in the second period.