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.

A system and method for mitigating interference of a radio frequency (RF) signal includes a receiver configured to include: a decomposition module that decomposes a received RF signal into sub-bands via a multi-stage filter, each sub-band being configured to operate on real and imaginary components of the RF signal, and each stage being scaled for separating time-frequency content of the desired signal from time-frequency content of the interference; a mitigation module that suppresses the interference of the RF signal in each sub-band by zeroing an output of a respective sub-band when the frequency content exceeds a predetermined threshold; and a reconstruction module that reconstructs the RF signal from the mitigation module minus the interference. The receiver is configured to determine whether the multi-stage filter is to be reinitialized with updated time and frequency resolution requirements to improve system response.

A system that incorporates the subject disclosure may perform, for example, a method that determines at least one threshold for detecting signal interference in a first plurality of segments occurring in a first radio frequency spectrum of a first wireless communication system, detecting a pattern of recurrence over time of signal interference in a segment of the first plurality of resource blocks according to the at least one threshold, and performing one or more mitigation steps to mitigate the signal interference without filtering the signal interference where the one or more mitigation steps include at least one of transmitting signals out of phase from the signal interference, adjusting transmit power, increasing power in a resource block of a long term evolution communication session, performing beam steering, or changing time parameters for the resource block without changing to a new resource block. Other embodiments are disclosed.

A method and device for downlink signal transmission in a dual-connection architecture, and a terminal. The method comprises: when a first signal receiver and a second signal transmitter both operate, after a second uplink signal and a higher harmonic signal of a first uplink signal enter a first downlink and before entering the first signal receiver, using a notch filter arranged on the first downlink to filter out a signal located in a preset frequency band in the second uplink signal.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may perform online spur detection and mitigation scheme. The UE may identify spurs during operation, in real time, and apply cancelation and noise equalization to address identified spurs. The UE may apply a high pass filter to reference signals. During a symbol, the UE may apply the high pass filter by estimating the channel on one or more neighbor tones (e.g., tones of higher frequency and tones of lower frequency that also carry reference symbols). Because the UE may assume that a channel will generally be smooth, and that noise may vary slowly or steadily across frequency resources, the UE may compare the channel noise of a particular tone to an average or normalized channel noise of the one or more neighbor tones.

Wireless signal processing may be improved by using a configurable baseband filter (BBF) in the receive path of a transceiver. A configurable BBF may accommodate processing of different wireless signals in a single integrated circuit (IC) chip. For example, a single IC may support processing of 5G mmWave RF signals and 5G sub-7 GHz RF signals by reconfiguring the BBF with settings appropriate for the different wireless signals. The reconfiguring of the BBF may include adjusting a bandwidth of the BBF and/or adjusting a filter order of the BBF. The reconfiguring of the BBF may be performed in response to detection of jammer signals to improve rejection of the jammer signals.

Disclosed are an airborne electromagnetic wave device, and an anti-interference system, method and apparatus. The anti-interference method comprises: detecting an interference source, and obtaining a working frequency and a bandwidth of the interference source; calculating an interfered bandwidth range at least on the basis of the working frequency and bandwidth of the interference source; and controlling an electrically tunable filter provided in a transmission channel of the airborne electromagnetic wave device to filter signals within the interfered bandwidth range. Hence, the interfered airborne electromagnetic wave device is triggered to control the electrically tunable filter to filter the signals within the interfered bandwidth range, so that the interfered airborne electromagnetic wave device suspends signal transmission within the interfered bandwidth range, so that communication interference among different satellite communication systems is eliminated; moreover, the electrically tunable filter is provided on the transmission channel of the interfered airborne electromagnetic wave device, so that the present invention can be widely applied to multiple different airborne electromagnetic wave devices and has relatively wide applicability.

Methods, systems, and devices for wireless communications are described. A transmitting (Tx) device transmits, to a receiving (Rx) device, a control message indicating a location of one or more noise spurs associated with wireless communications performed by the Tx device using a set of resources, where the location includes a frequency location of the one or more noise spurs in the frequency domain. The Tx device then generates a data message to be communicated using the set of resources associated with the one or more noise spurs based on transmitting the control message, and transmits the generated data message to the Rx device using the set of resources associated with the one or more noise spurs. By indicating the location of the noise spurs, the Rx device may be more able to more efficiently identify and address (e.g., filter out, ignore) the noise spurs within the data message.

Circuits and methods that provide fine-resolution measurements of RF signal power within a communication system band, thereby more accurately measuring RF interference or the potential of RF interference. One aspect of embodiments of the present invention is a narrow-band tunable filter that includes two elements coupled in series, a periodic passband filter and a tunable filter. The purpose of the periodic passband filter is to generate multiple periodic passbands for an applied RF signal. The purpose of the tunable filter is to generate a single passband, generally with a tunable center frequency. By serially coupling the two filter types in either order, the single passband of the tunable filter is superimposed over one of the periodic passbands of the periodic passband filter, synergistically resulting in an extremely narrow passband.

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.