Abstract: The invention relates to a mixer for generating an analog output signal XOUT from an analog input signal XIN using a mixing signal having a mixing frequency fMIX, the mixer comprising: a scaler being configured to sample the analog input signal XIN at a plurality of discrete points in time k with a sampling frequency fS to obtain a sampled analog input signal XIN[k] having a continuous signal value, and to generate the analog output signal XOUT having a continuous signal value by scaling the sampled analog input signal XIN[k] on the basis of a plurality of scaling coefficients A[k], wherein the scaling coefficients A[k] are a time-discrete representation of the mixing signal.

Abstract: The invention relates to a mixer for generating an analog output signal XOUT from an analog input signal XIN using a mixing signal having a mixing frequency fMIX, the mixer comprising: a scaler being configured to sample the analog input signal XIN at a plurality of discrete points in time k with a sampling frequency fS to obtain a sampled analog input signal XIN[k] having a continuous signal value, and to generate the analog output signal XOUT having a continuous signal value by scaling the sampled analog input signal XIN[k] on the basis of a plurality of scaling coefficients A[k], wherein the scaling coefficients A[k] are a time-discrete representation of the mixing signal.

Abstract: The disclosure relates to an error-compensated direct digital modulation device, including: a direct digital radio frequency modulator (DDRM), configured to generate a radio frequency (RF) signal based on a modulation of a digital baseband signal; an error estimator configured to determine an error signal resulting from a deviation based on the generated RF signal and a representation of the digital baseband signal; and an error compensator configured to subtract the error signal from the RF signal to provide an error compensated RF signal.

Abstract: A communication apparatus including a first mixer configured to generate an analog output signal (XOUT) from an analog input signal (XIN) using a first mixing signal, a second mixer configured to generate an analog output signal (YOUT) from an analog input signal (YIN) using a second mixing signal, and a local oscillator configured to provide a reference frequency (fREF), where the first mixer is configured to derive a first sampling frequency (fS,1) from the fREF, and where the second mixer is configured to derive a second sampling frequency (fS,2) from the fREF.

Abstract: The disclosure relates to an error-compensated direct digital modulation device, including: a direct digital radio frequency modulator (DDRM), configured to generate a radio frequency (RF) signal based on a modulation of a digital baseband signal; an error estimator configured to determine an error signal resulting from a deviation based on the generated RF signal and a representation of the digital baseband signal; and an error compensator configured to subtract the error signal from the RF signal to provide an error compensated RF signal.

Abstract: A communication apparatus including a first mixer configured to generate an analog output signal (XOUT) from an analog input signal (XIN) using a first mixing signal, a second mixer configured to generate an analog output signal (YOUT) from an analog input signal (YIN) using a second mixing signal, and a local oscillator configured to provide a reference frequency (fREF), where the first mixer is configured to derive a first sampling frequency (fS,1) from the fREF, and where the second mixer is configured to derive a second sampling frequency (fS,2) from the fREF.

Abstract: A mixer for generating an analog output signal XOUT from an analog input signal XIN using a mixing signal having a mixing frequency fMIX, the mixer comprising: a scaler being configured to sample the analog input signal XIN at a plurality of discrete points in time k with a sampling frequency fS to obtain a sampled analog input signal XIN[k] having a continuous signal value, and to generate the analog output signal XOUT having a continuous signal value by scaling the sampled analog input signal XIN[k] on the basis of a plurality of scaling coefficients A[k], wherein the scaling coefficients A[k] are a time-discrete representation of the mixing signal.

Abstract: Circuitry for any of a transceiver, a transmitter, and a receiver, has radio frequency (RF) circuitry, digital circuitry, a carrier signal generator to provide a carrier signal to the RF circuitry and a clock generator for generating a digital clock for clocking at least some of the digital circuitry. The RF circuitry is susceptible to interference from harmonics of the clocking, and the clock generator derives a frequency of the digital clock based on a frequency divided down from a frequency of the carrier signal so that the interference to the RF circuitry occurs at frequencies which are harmonics of the carrier signal.

Abstract: Circuitry for any of a transceiver, a transmitter, and a receiver, has radio frequency (RF) circuitry, digital circuitry, a carrier signal generator to provide a carrier signal to the RF circuitry and a clock generator for generating a digital clock for clocking at least some of the digital circuitry. The RF circuitry is susceptible to interference from harmonics of the clocking, and the clock generator derives a frequency of the digital clock based on a frequency divided down from a frequency of the carrier signal so that the interference to the RF circuitry occurs at frequencies which are harmonics of the carrier signal.

Abstract: Full duplex radio wireless systems and methods and especially transceivers for full duplex radio wireless systems with reduction of self-interference are described. MIMO (=multiple input multiple output several antennas for output and input) is used within one device with multiple antennas to remove self-interference in a proactive way.

Abstract: A method for estimating the distance between a transmitter and at least one receiver. The transmitter has radio transmission circuitry, at least part of which is operable in a first operation mode for transmitting a first signal type within a first bandwidth and in a second operation mode for transmitting a second signal type including at least a ranging component which occupies a second bandwidth which encompasses and exceeds the first bandwidth. The method includes the steps of: (i) operating part of the radio transmission circuitry in a second operation mode, (ii) transmitting a signal of a second signal type, (iii) receiving a signal on one receiver and (iv) estimating the distance between the transmitter and a receiver from the ranging component in each received signal. A suitable transmitter and receiver for implementing the method are described.

Abstract: A method of transmitting data signals from at least two transmitting terminals to at least one receiving terminal with a spatial diversity antenna comprises transmitting from the transmitting terminals transformed data signals, being transformed versions of the data signals; receiving on the spatial diversity means received data signals being at least function of at least two of the transformed data signals; subband processing of at least two of the received data signals in the receiving terminal; and determining estimates of the data signals from subband processed received data signals in the receiving terminal.

Abstract: Full duplex radio wireless systems and methods and especially transceivers for full duplex radio wireless systems with reduction of self-interference are described. MIMO (=multiple input multiple output several antennas for output and input) is used within one device with multiple antennas to remove self-interference in a proactive way.

Abstract: A system and method are provided for calibrating for an I/Q mismatch of a direct conversion receiver based on a random signal having a two-dimensional I versus Q trajectory, such as radio frequency (RF) noise. In general, the random signal is received and downconverted to a quadrature baseband signal having an in-phase component and a quadrature component. The variance of the in-phase component, the variance of the quadrature component, and the covariance of the in-phase component with the quadrature component are computed based on samples of the quadrature baseband signal. A correction matrix used to compensate for the I/Q mismatch of the receiver and/or I/Q mismatch including a gain mismatch and a phase mismatch of the receiver is then computed based on the variance of the in-phase component, the variance of the quadrature component, and the covariance of the in-phase component with the quadrature component.

Abstract: A method for estimating the distance between a transmitter and at least one receiver. The transmitter has radio transmission circuitry, at least part of which is operable in a first operation mode for transmitting a first signal type within a first bandwidth and in a second operation mode for transmitting a second signal type including at least a ranging component which occupies a second bandwidth which encompasses and exceeds the first bandwidth. The method includes the steps of: (i) operating part of the radio transmission circuitry in a second operation mode, (ii) transmitting a signal of a second signal type, (iii) receiving a signal on one receiver and (iv) estimating the distance between the transmitter and a receiver from the ranging component in each received signal. A suitable transmitter and receiver for implementing the method are described.

Abstract: Various methods and apparatus for frequency-domain estimation of carrier frequency offsets are provided in which the carrier frequency offset estimate is robust against non-white (frequency-dependent) noise. A carrier-specific weighting factor is associated with each carrier of a multi-carrier signal. Using the carrier-specific weighting factors, a carrier frequency offset estimate is computed from received signals and estimated channel transfer functions associated with each of the carriers. Because greater weights are given to carriers whose frequencies include lower noise and/or carriers transmitting a known sequence of symbols, the estimate of the carrier frequency offset is improved. The carrier frequency offset estimate may then be applied in a feedback loop to phase-compensate a subsequently received signal.

Abstract: Various methods and systems efficiently implement broadband multi-carrier communication systems. The invention exploits the structural properties of a frequency-domain channel estimator and transforms it into the time domain. This allows the sharing of certain blocks of hardware (e.g., matched filters otherwise used for timing acquisition) which results in significant reduction of complexity.

Abstract: A method of transmitting data signals from at least two transmitting terminals to at least one receiving terminal with a spatial diversity antenna comprises transmitting from the transmitting terminals transformed data signals, being transformed versions of the data signals; receiving on the spatial diversity means received data signals being at least function of at least two of the transformed data signals; subband processing of at least two of the received data signals in the receiving terminal; and determining estimates of tbe data signals from subband processed received data signals in the receiving terminal.

Abstract: Circuitry for any of a transceiver, a transmitter, and a receiver, has radio frequency (RF) circuitry, digital circuitry, a carrier signal generator to provide a carrier signal to the RF circuitry and a clock generator for generating a digital clock for clocking at least some of the digital circuitry. The RF circuitry is susceptible to interference from harmonics of the clocking, and the clock generator derives a frequency of the digital clock based on a frequency divided down from a frequency of the carrier signal so that the interference to the RF circuitry occurs at frequencies which are harmonics of the carrier signal.

Abstract: Circuitry for any of a transceiver, a transmitter, and a receiver, has radio frequency (RF) circuitry, digital circuitry, a carrier signal generator to provide a carrier signal to the RF circuitry and a clock generator for generating a digital clock for clocking at least some of the digital circuitry. The RF circuitry is susceptible to interference from harmonics of the clocking, and the clock generator derives a frequency of the digital clock based on a frequency divided down from a frequency of the carrier signal so that the interference to the RF circuitry occurs at frequencies which are harmonics of the carrier signal.