A tracking and rejection filter for use in a receiver of a radio includes a selectable filter configured to provide an output digital in-phase signal and an output digital quadrature signal based on a center frequency, a digital in-phase signal corresponding to an in-phase component of a received radio frequency signal, and a digital quadrature signal corresponding to a quadrature component of the received radio frequency signal. The tracking and rejection filter includes a select circuit configured to select the center frequency of the selectable filter according to whether an interfering signal is detected in a target frequency band of the received radio frequency signal. The center frequency is selected from a predetermined frequency and an estimated center frequency determined using an instantaneous frequency signal. The instantaneous frequency signal is based on the digital in-phase signal and the digital quadrature signal.

Systems and methods for mitigating an effect interference. The methods comprise: receiving, by a device, a signal comprising a plurality of signal components; determining whether each signal component has a sufficient reconstructability; reconstructing each said signal component that was determined to have sufficient reconstructability using the received signal or an at least partially clean signal with other signal component(s) removed from the received signal; and using the reconstructed signal components to generate a modified received comprising the received signal with the signal components removed therefrom that (i) are devoid of a signal of interest and (ii) have sufficient reconstructability.

Systems, methods, and computer program product embodiments are disclosed for removing any fixed frequency interfering signal from an input signal without introducing artifacts that are not part of the original signal of interest. An embodiment operates by using a virtual buffer with a length that matches a length of one cycle of an interfering signal. The embodiment extracts the interfering signal into the virtual buffer. For a sample in the next cycle of the interfering signal that corresponds to a virtual memory location for the virtual buffer, the embodiment can update one or more physical memory locations of the virtual buffer that are in the vicinity of the virtual memory location. This use of virtual buffer can remove any interfering signal without creating the artifacts associated with conventional notch filters.

A device comprises a digital ramp generator, an oscillator, a power amplifier, a low-noise amplifier (LNA), a mixer, and an intermediate frequency amplifier (IFA). The oscillator generates a chirp signal based on an output from the digital ramp generator. The power amplifier receives the chirp signal and outputs an amplified chirp signal to a transmitter antenna. The LNA receives a reflected chirp signal from a receiver antenna. The mixer receives output of the LNA and combines it with the chirp signal from the oscillator. The IFA receives the mixer output signal and includes a configurable high-pass filter, which has a first cutoff frequency during a first portion of the chirp signal and a second cutoff frequency during a second portion of the chirp signal. In some implementations, the first cutoff frequency is chosen based on a frequency of a blocker signal introduced by couplings between the transmitter and receiver antennas.

A method for cancelling radio frequency interference (RFI) and a communication system thereof are provided. In the communication system, digital signals of a frequency domain are converted from analog signals and received by the communication system generally carry RFI, and the signals are processed by an equalizer and a far-end crosstalk canceller. Then, for preventing erroneous signals from forming due to an occurrence of a notch, masking parameters applied to the equalizer and the far-end crosstalk canceller are modified for not processing frequency bands that are RFI-affected. The frequency bands can be ignored by masking corresponding bins in the frequency domain after a fast Fourier transformation. The signals processed by the equalizer and the far-end crosstalk canceller are then outputted to an RFI canceller, and the signals with RFI cancellation can be obtained.

Disclosed in the present application are a method for reducing SGLTE coupling de-sense and a mobile terminal, the method including: filtering out an LTE network frequency band in a signal transmitted by a signal transmission end of a GSM; and filtering out a network frequency band in a signal of a signal reception end accessing the GSM other than a GSM network frequency band. Employing the present application may eliminate mutual interference between a GSM signal and an LTE signal due to the GSM network frequency band and the LTE network frequency band getting too close to each other, which greatly alleviates SGLTE mobile terminal coupling de-sense situation.

A system with an acoustic filter array for analog processing of radio signals above 8 GHz includes a receiver and a downconverter to down-convert an incoming signal into an intermediate frequency range (IF). Downconverter includes suppression of local oscillator image. An active manifold splits the IF signal into separate parallel feeds into individual acoustic filter elements in an acoustic filter array. Acoustic filter array provides individually channelized IF outputs. Each IF manifold feed and corresponding acoustic filter output channel is associated with an analog-to-digital converter or system switch.

The systems and methods described herein are directed to techniques for improving battery life performance of end devices in resource monitoring systems which transmit data using low-power, wide area network (LPWAN) technologies. Further, the techniques include providing sensor interfaces in the end devices configured to communicate with multiple types of metrology sensors. Additionally, the systems and methods include techniques for reducing the size of a concentrator of a gateway device which receives resource measurement data from end devices. The reduced size of the concentrator results in smaller, more compact gateway devices that consume less energy and reduce heat dissipation experienced in gateway devices. The concentrator may comply with modular interface standards, and include two radios configured for transmitting 1-watt signals. Lastly, the systems and methods include techniques for fully redundant radio architecture within a gateway device, allowing for maximum range and minimizing downtime due to transmission overlap.

A radio frequency receiver with adaptive dynamic filtering controlled by signals from subsequent or external circuit elements, as required to suppress undesired radio frequency energy, match the radio's input circuit to the received signal, and permit optimized processing of the signal of interest.

An apparatus is disclosed for implementing an antenna tuner. In an example aspect, the apparatus includes a substrate, an antenna disposed on or in the substrate, a radio-frequency integrated circuit disposed on the substrate, and an antenna tuner. The radio-frequency integrated circuit includes an amplification circuit. The antenna tuner is coupled between the antenna and the amplification circuit. The antenna tuner includes an inductive component disposed on or in the substrate and a capacitive component implemented within the radio-frequency integrated circuit.