The disclosed systems and methods are directed to wireless receiver systems for neutralizing the effects of received RF blocking signals. The configurations presented herein operate to receive RF signals containing a desired signal and a blocking signal, a first module, in communication with the receive RF signals along a first signal path and configured to extract a specimen of the received desired and blocking signals, and a second module, in communication with the first module along a second signal path to receive the desired signal and blocking signal specimens. The second module is configured to produce a replica of the blocking signal based on the blocking signal specimen, generate an anti-blocking signal based on the blocking signal replica, and introduce the anti-blocking signal to the received desired and blocking signals in which the anti-blocking signal destructively interferes to neutralize the received blocking signal.

Certain aspects of the disclosure related to communications apparatus provides isolation between wireless protocols when operating currently while incurring the additional insertion loss based on providing the isolation only when needed. In an aspect, an apparatus include a switched filter coupled to an antenna where the switched filter includes a filter and a bypass line along with switching circuitry configured to selectively establish a bypass signal path including the bypass line or a filtered signal path including the filter. The apparatus further includes a switched filter controller configured to cause the switching circuitry to selectively connect a transceiver unit to the antenna via the bypass signal path or via the filtered signal path based at least on a frequency band of a carrier signal and a bandwidth of the carrier signal.

A controller is configured to control the adaptive notch filter and to execute a search technique (e.g., artificial intelligence (AI) search technique) to converge on filter coefficients and to recursively adjust the filter coefficients of the adaptive notch filter in real time to adaptively adjust one or more filter characteristics (e.g., maximum notch depth or attenuation, bandwidth of notch, or general magnitude versus frequency response of notch).

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.

A radio frequency (RF) filter includes a signal conditioning circuit and a bandstop filter. The signal conditioning circuit receives a broadband RF signal that includes both a jamming signal at a jamming frequency and a signal of interest and generates a plurality of clock signals. Each of the plurality of clock signals has a substantially same frequency as the jamming frequency, but a different phase shift. The bandstop filter receives the RF signal and the plurality of clock signals. The bandstop filter attenuates signals within a bandstop centered at the frequency of the plurality of clock signals. A self-tuning N-path filter is provided.

Apparatus and methods for envelope controlled radio frequency (RF) switches are provided. In certain embodiments, a power amplifier provides an RF signal to an antenna by way of an RF switch. Additionally, the envelope signal is used not only to control a power amplifier supply voltage of the power amplifier, but also to control a regulated voltage used to turn on the RF switch. For example, a level shifter can use a regulated voltage from charge pump circuitry to turn on the RF switch, and the envelope signal can be provided to the charge pump circuitry and used to control the voltage level of the regulated voltage over time.

A multiplexer circuit with good isolation characteristics and a compensated frequency characteristic at the transmission side is presented. The multiplexer circuit has a reception filter notch circuit (RFNC) active at a frequency within a passband of a reception filter (RXF) and coupled between an input port and a transmission filter (TXF).

A system that incorporates aspects of the subject disclosure may perform operations including, for example, receiving, via an antenna, a signal generated by a communication device, detecting passive intermodulation interference in the signal, the interference generated by one or more transmitters unassociated with the communication device, and the interference determined from signal characteristics associated with a signaling protocol used by the one or more transmitters. Other embodiments are disclosed.

A noise reduction system for a digital receiver reduces noise in signals received at the digital receiver. The digital receiver includes an input for receiving an analogue signal, analogue signal processing circuitry for processing an analogue signal, and an output for providing the processed signal to a digital signal processor. The noise reduction system is located between the input and the digital receiver input, and includes a first component that outputs results of a noise signal identification and a second component that applies one or more counter-measure to the received analogue signal to produce a modified analogue signal. The modified analogue signal has a reduced level of noise compared to the received analogue signal, wherein the noise reduction system is arranged to assess the effectiveness of the one or more counter-measures applied by the second component to determine whether any further counter-measures are required.

A Multi-Signal Instantaneous Frequency Measurement, MIFM, system comprising a front end adapted to shift and combine signal spectra of different sub-frequency bands (SFBs) of a received wideband signal (WBS) into an intermediate frequency band (IFB) having an instantaneous bandwidth (IBW), wherein each shifted SFB signal spectrum is marked individually with SFB marking information associated with the respective sub-frequency band (SFB) and a digital receiver (3) having the instantaneous bandwidth (IBW) configured to process the shifted SFB signal spectra within the intermediate frequency band (IFB) using the SFB marking information to resolve any frequency ambiguity caused by the shifting and combining of the SFBs signal spectra.