Embodiments related to retransmission in a communication system are described and depicted. In one embodiment, a retransmission entity repeats a transmission of a data transfer unit by the device after a predetermined number of other transmitted data transfer units has been transmitted. The retransmission entity may also determine whether a measure for a time period since the first transmission of the data transfer unit by the device has exceeded a predetermined threshold and to provide a final transmission of the data transfer unit based on the determining that the measure for the time period has exceeded the predetermined threshold.

An apparatus for determining an eye mask of a device under test (DUT) which is configured to receive a data bit stream signal including a threshold level value and output a data bit stream output signal. The apparatus includes an input unit configured to receive the data bit stream output signal provided by the DUT, an evaluation unit configured to evaluate the received data bit output signal and provide an evaluation result, and a controller configured to change the threshold level value in response to the evaluation result. The apparatus is integrated into the DUT and can operates autonomously without multiple interactions with a tester.

Various solutions for cross-link interference measurements with respect to user equipment and network apparatus in mobile communications are described. A node of a wireless network may receive a cross-link interference (CLI) measurement configuration. The node may determine a measurement slot according to the CLI measurement configuration. The node may determine whether to perform a CLI measurement in the measurement slot according to the CLI measurement configuration. The node may receive a CLI reference signal (RS) in the measurement slot. The node may perform the CLI measurement in the measurement slot.

When an STA receives first to fifth SSW frames (first training frames) transmitted from an AP, the STA measures reception quality thereof, and transmits a reception quality measurement result to the AP by incorporating the reception quality measurement result in an SSW-ACK frame (first feedback frame). In response, the AP selects a beam pattern satisfying a specific selection criterion based on the reception quality measurement result and employs the selected beam pattern as the transmission beam pattern for use in transmission to the STA.

Certain aspects of the present disclosure provide techniques for dynamic configuration of demodulation reference signals (DMRSs). A method that may be performed by a base station (BS) includes receiving one or more uplink signals from at least one user equipment (UE); estimating a Doppler shift associated with the one or more uplink signals; determining a density of reference signals (RSs) within a slot for the at least one UE based, at least in part, on the estimated Doppler shift associated with the one or more uplink signals; and transmitting information to the at least one UE indicating an allocation of RS resources for the UE, wherein the allocation of the RS resources is based on the density of the RSs for the at least one UE.

Disclosed are various embodiments for a system and method of measuring and characterizing a PLC communication network comprising transmitting a plurality of packets from a PLC master device to a PLC terminal device via a PLC communication network, measuring a plurality of round-trip time (RTT) timestamps for the plurality of packets in the PLC master device, determining an observed probability density function based on the plurality of RTT timestamps, approximating a plurality of probability density functions, determining a rating for the probability density functions based on a comparison of the probability density functions to the observed probability density function, characterizing the PLC communication network based on the ratings of the plurality of probability density functions, and scheduling subsequent transmissions based on the characterization of the PLC Communication network.

An apparatus for determining an eye mask of a device under test (DUT) which is configured to receive a data bit stream signal including a threshold level value and output a data bit stream output signal. The apparatus includes an input unit configured to receive the data bit stream output signal provided by the DUT, an evaluation unit configured to evaluate the received data bit output signal and provide an evaluation result, and a controller configured to change the threshold level value in response to the evaluation result. The apparatus is integrated into the DUT and can operates autonomously without multiple interactions with a tester.

Determining ambient noise in a device under test electromagnetic compatibility test environment is presented herein. A method can include determining, by a system comprising a processor via a radio frequency input port of the system, an ambient electromagnetic noise corresponding to the system; and in response to determining, by the system via the radio frequency input port, a radio frequency signature of a device under test, subtracting, by the system, the ambient electromagnetic noise from the radio frequency signature to obtain a normalized value representing an electromagnetic emission of the device under test. In an example, an antenna/coaxial cable has been connected to the radio frequency input port, the ambient electromagnetic noise can be determined using the antenna/coaxial cable, and a radiated/conducted electromagnetic characteristic of the device under test representing the radio frequency signature of the device under test can be determined using the antenna/coaxial cable.

A system and method employ an exclusive-OR gate having a first input configured to receive an RF carrier signal having an RF carrier, and a second input configured to receive a square wave signal having a square wave frequency, to output to a signal processing channel under test a binary phase shift keying (BPSK) signal comprising the RF carrier signal modulated by the square wave signal. A digital signal processor is configured to receive from the signal processing channel in-phase (I) and quadrature-phase (Q) data produced by the signal processing channel in response to the BPSK signal, and to process the I and Q data to determine an amplitude response and phase response of the signal processing channel as a function of frequency.

Detecting PIM in a downstream signal, wherein the downstream signal is received from a cable plant via a subscriber network and an upstream signal is transmitted to the cable plant via the subscriber network. The upstream signal is transmitted in bursts during active intervals. PIM arises from an interaction between the upstream signal and a nonlinear component in the subscriber network and occurs in bursts corresponding to the upstream signal. The detection steps are: (a) identifying the potentially affected downstream signal from the upstream signal; (b) receiving the downstream signal during an active interval; (c) measuring a metric of the downstream signal to obtain an active value; (d) receiving the downstream signal during a quiet interval; (e) measuring the metric of the downstream signal to obtain a quiet value; (f) comparing active and quiet values; and (g) determining whether PIM distortion has been detected based on the comparison.