A method includes transmitting, by a transceiver configured to concurrently transmit over multiple transmit paths and receive over multiple receive paths, one or more signals, the transceiver comprising multiple transmit antennas and multiple receive antennas. The method also includes, for at least one of the multiple receive antennas: receiving one or more feedback signals from one or more power amplifiers associated with the one or more transmitted signals; calculating one or more estimated self-interference (SI) signals based on the one or more feedback signals using an equalizer array comprising a predetermined channel model; and subtracting the one or more estimated SI signals from one or more receive signals received at the at least one receive antenna to obtain one or more residual signals.

A test device tests conditions associated with a fronthaul in an Open Radio Access Network (O-RAN). The test device can field test an O-RAN radio unit (O-RU) installed at a cell site by emulating an O-RAN distributed unit (O-DU) in the O-RAN connected to the O-RU via the fronthaul of the O-RAN. The testing includes testing connectivity of the O-RU to the fronthaul. The testing includes executing managing plane (M-plane) and synchronization plane (S-plane) messaging to test management session establishment, device setting testing, and master clock synchronization testing. Additionally, optical insertion loss in the fronthaul and frequency and power of signals transmitted from the O-RU can be tested.

Materials and methods for mitigating passive intermodulation. A membrane for reducing passive intermodulation includes a first polymeric layer, a second polymeric layer, and a continuous metal layer encapsulated between the first and second polymeric layers. A self-adhesive radio frequency barrier tape includes a waterproof polymeric top layer, a metal-containing layer adhered by an adhesive layer to the polymeric top layer, a pressure sensitive adhesive layer adhered to the metal-containing layer, and a release liner on a bottom surface of the pressure sensitive adhesive layer. A method of mitigating passive intermodulation includes passing a probe over an area of interest, the probe being sensitive to an intermodulation frequency of interest, and identifying a suspected source of passive intermodulation when the amplitude of the probe output exceeds a threshold at the frequency of interest. The method further includes covering the suspected passive intermodulation source with a radio frequency barrier material.

According to one embodiment, a transceiver includes: a radio transmitter including a power amplifier; a detector circuit including: a squaring circuit configured to receive an output of the power amplifier of the radio transmitter and configured to produce an output current; and a DC current absorber electrically connected to an output terminal of the squaring circuit.

A base station (UE) is configured to perform a computer-implemented method for antenna fault detection and correction. The computer-implemented method includes acquiring one or more sounding reference signals (SRSs) received from at least one gNB antenna; detecting an antenna failure based on the one or more SRSs; estimating a noise power based on the antenna failure and a history of received SRSs; detecting a missing SRS based on the noise power and the history of received SRSs; and handling the missing SRS. Handling the missing SRS is based on performing at least one of: replacing an SRS measurement with a predicted SRS value for the missing SRS when the predicted SRS is available; or avoiding use of the missing SRS in a sequential SRS prediction when the predicted SRS is unavailable.

Method of determining a position of a plurality of mobile network devices relative to a plurality of reference network devices, wherein the plurality of mobile network devices and the plurality of reference network devices communicate with one another over a wireless channel and access the wireless channel according to an access policy comprising a sequence of time frames, wherein each time frame of the sequence comprises a plurality of portions reserved for communicating messages relating to different time-of-flight (ToF) computation methods, each of the different ToF computation methods allowing for determining a position of at least one of the plurality of mobile network devices. A positioning system implements the above method.

Provided are a measurement system and a radio wave shielding member that include a radio wave absorber that has light transmittance and absorbs radio waves other than the radio waves to be measured, and thus is suitable for the measurement of radio wave properties.

The measurement system includes a measuring target device 11, a measuring device 12 that emits and/or receives radio waves to measure the measuring target device, and a radio wave absorber 10 that has light transmittance and absorbs radio waves in and above the millimeter wave band. The radio wave absorber includes a transparent support member 2 and a radio wave absorbing sheet 1 that is attached to one surface of the support member. The radio wave absorbing sheet includes a resistive film 3, a dielectric layer 4, and a radio wave shielding layer 5 which are stacked on top of each other and all of which have light transmittance. The radio wave absorber blocks and/or absorbs unwanted radio waves around the measuring target device.

Provided is an apparatus and method for transmitter identification. A transmitter identification apparatus may include a communicator configured to receive a signal from a transmitter at least once; and a processor configured to acquire a clock offset using the received signal, to acquire a cumulative clock offset by accumulating the clock offset, and to acquire analysis data based on a variance of the cumulative clock offset over time.

An absorber device for absorbing signals is described. The absorber device has a housing with inner sides having an absorbing material. The housing is adaptable with regard to its geometry. The absorber device is portable. Moreover, a test system for testing radio frequency characteristics of a device under test is described.

Disclosed is an electronic device that includes a transmission amplifier; an antenna; a circulator disposed between the transmission amplifier and the antenna; a communication module which is connected to the circulator and which is for checking a signal received through the antenna; and a processor. The processor may be set to check the signal through the communication module and adjust the frequency characteristics of the antenna based at least in part on a determination that the signal is a signal reflected from the antenna.