A very low intermediate frequency receiver and methods for controlling the same. One method includes providing, using a local oscillator, a first intermediate frequency, detecting, using an interferer detector, an adjacent or alternate channel interference signal and an image of the adjacent or adjacent channel interference signal causing interference with a desired signal, and determining, using an electronic processor, whether the desired signal is an analog signal. In response to determining that the desired signal is an analog signal, the method includes controlling, using the electronic processor, the local oscillator to provide a second intermediate frequency. In response to determining that the desired signal is not an analog signal, the method includes determining, using the electronic processor, a switching condition based on the desired signal, and controlling, using the electronic processor, the local oscillator to provide the second intermediate frequency in response to determining the switching condition.

Systems and methods are provided for peak to average power ratio (PAPR) reduction in multichannel digital front-ends (DFEs). A transmitter may be configured to reduce PAPR during multichannel transmission, with the reducing comprising: generating a plurality of frequency-domain symbols, each of which corresponding to a particular one of a plurality of subcarriers; assigning the subcarriers to a plurality of channels, wherein a number of channels is less than a number of subcarriers; and generating a plurality of time-domain signals corresponding to the channels. An adjustment to reduce PAPR may be applied to at least one of the time-domain signals, with the adjustment being based on symbols boundaries. The adjustment may comprise sign inversion. Adjusted and unadjusted waveforms may be generated for two or more of the time-domain signals; and selection may be made between generated adjusted waveforms based on particular criteria. The criteria may comprise lowest peak.

An apparatus, method and computer program is described comprising: obtaining time domain samples of a received radio frequency signal of a mobile communication system, wherein the radio frequency signal comprises a Physical Random Access Channel; determining an estimated power distribution for the time domain samples; determining a filtering threshold value at which a time domain sample is deemed to be due to interference, based on a defined probability level of the estimated power distribution; defining a filtering mask based on the time domain samples and the filtering threshold; and applying the filtering mask to the time domain samples to generate a filtered signal samples, wherein the filtering mask is configured to attenuate time domain samples that are above the filtering threshold.

A very low intermediate frequency receiver and methods for controlling the same. One method includes providing, using a local oscillator, a first intermediate frequency, detecting, using an interferer detector, an adjacent or alternate channel interference signal and an image of the adjacent or adjacent channel interference signal causing interference with a desired signal, and determining, using an electronic processor, whether the desired signal is an analog signal. In response to determining that the desired signal is an analog signal, the method includes controlling, using the electronic processor, the local oscillator to provide a second intermediate frequency. In response to determining that the desired signal is not an analog signal, the method includes determining, using the electronic processor, a switching condition based on the desired signal, and controlling, using the electronic processor, the local oscillator to provide the second intermediate frequency in response to determining the switching condition.

Systems, methods, and circuitries are disclosed for generating a desired signal from a received signal. In one example a signal cancellation system includes local oscillator (LO) downconverter circuitry, frequency offset (FO) signal estimation circuitry, and cancellation circuitry. The LO downconverter is configured to downconvert the received signal using an LO signal having an LO frequency to generate a downconverted received signal. The FO signal estimation circuitry includes FOLO generation circuitry configured to modify the LO signal to generate a FOLO signal having an offset frequency that is different from the LO frequency and FOLO downconverter circuitry configured to use the FOLO signal to downconvert a signal derived from the received signal to generate a downconverted FO signal. The cancellation circuitry is configured to cancel either the downconverted received signal or the downconverted FO signal from the received signal to generate the desired signal.

A quadrature ADC feedback compensation system and method for MEMS gyroscope is disclosed. In an embodiment, a MEMS gyroscope comprises an analog processing chain including a drive circuit for generating an analog drive signal and a sense circuit that is configured to generate an analog rate signal and an analog quadrature signal in response to a change in capacitance output by the MEMS gyroscope. A compensation circuit coupled to the sense circuit is configured to null the analog quadrature signal using the analog drive signal and a compensation value, and to adaptively compensate, in a digital processing chain, a quadrature-induced rate offset of a digital rate signal over temperature using a digital quadrature signal, the compensation value and temperature data.

A quadrature ADC feedback compensation system and method for MEMS gyroscope is disclosed. In an embodiment, a MEMS gyroscope comprises an analog processing chain including a drive circuit for generating an analog drive signal and a sense circuit that is configured to generate an analog rate signal and an analog quadrature signal in response to a change in capacitance output by the MEMS gyroscope. A compensation circuit coupled to the sense circuit is configured to null the analog quadrature signal using the analog drive signal and a compensation value, and to adaptively compensate, in a digital processing chain, a quadrature-induced rate offset of a digital rate signal over temperature using a digital quadrature signal, the compensation value and temperature data.

Systems and methods are provided for peak to average power ratio (PAPR) reduction in multichannel transmissions. A plurality of frequency-domain symbols may be generated and assigned to a plurality of subcarriers associated with a multichannel transmission. The subcarriers may be assigned to a plurality of channels used for the multichannel transmission, with a number of the channels being different than a number of the subcarriers. A plurality of time-domain signals corresponding to the plurality of channels may be generated, and an adjustment may be applied to at least one time-domain signal, to generate a corresponding adjusted time-domain signal. The adjustment may be configured based on one or more characteristic associated with at least two of the frequency-domain symbols. Handling related information may be communicated form the transmit-side to the receive-side, such as using spare carriers, to enable handling an output corresponding to the plurality of time-domain signals.

Systems, methods, and circuitries are disclosed for generating a desired signal from a received signal. In one example a signal cancellation system includes local oscillator (LO) downconverter circuitry, frequency offset (FO) signal estimation circuitry, and cancellation circuitry. The LO downconverter is configured to downconvert the received signal using an LO signal having an LO frequency to generate a downconverted received signal. The FO signal estimation circuitry includes FOLO generation circuitry configured to modify the LO signal to generate a FOLO signal having an offset frequency that is different from the LO frequency and FOLO downconverter circuitry configured to use the FOLO signal to downconvert a signal derived from the received signal to generate a downconverted FO signal. The cancellation circuitry is configured to cancel either the downconverted received signal or the downconverted FO signal from the received signal to generate the desired signal.

Systems and methods are provided for peak to average power ratio (PAPR) reduction in multichannel transmissions. A plurality of frequency-domain symbols may be generated and assigned to a plurality of subcarriers associated with a multichannel transmission. The subcarriers may be assigned to a plurality of channels used for the multichannel transmission, with a number of the channels being different than a number of the subcarriers. A plurality of time-domain signals corresponding to the plurality of channels may be generated, and an adjustment may be applied to at least one time-domain signal, to generate a corresponding adjusted time-domain signal. The adjustment may be configured based on one or more characteristic associated with at least two of the frequency-domain symbols. Handling related information may be communicated form the transmit-side to the receive-side, such as using spare carriers, to enable handling an output corresponding to the plurality of time-domain signals.