Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A distance measuring device includes a calculating section configured to calculate, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first reference signal source and a first transceiver configured to transmit two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source. The second device includes a second reference signal source configured to operate independently from the first reference signal source and a second transceiver configured to transmit the second carrier signals and receives the first carrier signals using an output of the second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals.

Abstract: A distance measuring device includes a calculating section configured to calculate, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first reference signal source and a first transceiver configured to transmit two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source. The second device includes a second reference signal source configured to operate independently from the first reference signal source and a second transceiver configured to transmit the second carrier signals and receives the first carrier signals using an output of the second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A computer-implemented method of estimating IQ imbalance in a communication system including a transmitter and a receiver. The method includes: defining a system model in which a transmitted signal is affected by TX IQ imbalance, carrier frequency offset (CFO) and RX IQ imbalance; controlling a local oscillator at the transmitter to introduce a known carrier frequency offset (CFO) during a calibration; and estimating unknown parameters in the system model using a pre-defined training sequence to determine the TX IQ imbalance and the RX IQ imbalance.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A carrier leakage correction method for a quadrature modulator according to an embodiment includes inputting a test signal with a frequency fBB to a transmitter and up-converting the test signal with a frequency fL0 and down-converting with the frequency fL0. A frequency 2fBB component is detected in the down-converted test signal. One or a plurality of parameters of the transmitter is/are adjusted so as to reduce a magnitude of the detected frequency 2fBB component in the test signal.

Abstract: According to an embodiment, a communication device includes a phase-shifting circuit that shifts a phase of a local signal and supplies it to an orthogonal demodulator. The phase-shifting circuit includes first and second signal input ends that are supplied with an output signal of a local oscillator between both ends thereof, a frequency divider that has first and second input ends, and a switching part that is provided between the first and second signal input ends and the first and second input ends of the frequency divider and switches connection between the first and second signal input ends and the first and second input ends of the frequency divider.

Abstract: A carrier leakage correction method for a quadrature modulator according to an embodiment includes inputting a test signal with a frequency fBB to a transmitter and up-converting the test signal with a frequency fL0 and down-converting with the frequency fL0. A frequency 2fBB component is detected in the down-converted test signal. One or a plurality of parameters of the transmitter is/are adjusted so as to reduce a magnitude of the detected frequency 2fBB component in the test signal.

Abstract: A carrier leakage correction method for a quadrature modulator according to an embodiment includes inputting a test signal with a frequency fBB to a transmitter and up-converting the test signal with a frequency fL0 and down-converting with the frequency fL0. A frequency 2fBB component is detected in the down-converted test signal. One or a plurality of parameters of the transmitter is/are adjusted so as to reduce a magnitude of the detected frequency 2fBB component in the test signal.

Abstract: An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.

Abstract: A carrier leakage correction method for a quadrature modulator according to an embodiment includes inputting a test signal with a frequency fBB to a transmitter and up-converting the test signal with a frequency fL0 and down-converting with the frequency fL0. A frequency 2fBB component is detected in the down-converted test signal. One or a plurality of parameters of the transmitter is/are adjusted so as to reduce a magnitude of the detected frequency 2fBB component in the test signal.

Abstract: A distance measuring device includes a calculating section configured to calculate, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first reference signal source and a first transceiver configured to transmit two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source. The second device includes a second reference signal source configured to operate independently from the first reference signal source and a second transceiver configured to transmit the second carrier signals and receives the first carrier signals using an output of the second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A transmission and reception circuit includes a transmission circuit, a reception circuit, and a signal feedback path. The transmission path includes an output section, a signal generating circuit generating an in-phase component signal and an orthogonal component signal, and a transmission analog baseband circuit configured to perform digital to analog conversion of the generated in-phase component signal and orthogonal component signal. The reception circuit includes an input section, a reception analog baseband circuit performing analog to digital conversion of the transmitted in-phase component signal and orthogonal component signal, and a signal detection circuit that detects the analog-to-digital converted in-phase component signal and orthogonal component signal converted by the reception analog baseband circuit.

Abstract: According to an embodiment, a communication device includes a phase-shifting circuit that shifts a phase of a local signal and supplies it to an orthogonal demodulator. The phase-shifting circuit includes first and second signal input ends that are supplied with an output signal of a local oscillator between both ends thereof, a frequency divider that has first and second input ends, and a switching part that is provided between the first and second signal input ends and the first and second input ends of the frequency divider and switches connection between the first and second signal input ends and the first and second input ends of the frequency divider.

Abstract: A transmission and reception circuit includes a transmission circuit, a reception circuit, and a signal feedback path. The transmission path includes an output section, a signal generating circuit generating an in-phase component signal and an orthogonal component signal, and a transmission analog baseband circuit configured to perform digital to analog conversion of the generated in-phase component signal and orthogonal component signal. The reception circuit includes an input section, a reception analog baseband circuit performing analog to digital conversion of the transmitted in-phase component signal and orthogonal component signal, and a signal detection circuit that detects the analog-to-digital converted in-phase component signal and orthogonal component signal converted by the reception analog baseband circuit.

Abstract: An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.