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.

An anechoic chamber and test system that is adapted for installation in or to a vehicle. The chamber includes an outer structure that is durable enough to withstand the effects of transportation. The anechoic chamber and test system may also include an inner faraday shield, a transmission antenna, and a controller that can introduce GNSS, alternative navigation signals, jamming, or spoofing signals into the anechoic chamber along with vehicle sensor signals. The controller is adapted to monitor a GNSS system's ability to resist the jamming or spoofing signals using, at least in part, the vehicle sensor signals.

A transceiving device includes a calibration signal generation unit, a phase adjusting unit, a transmission unit, a receiving unit, and a calibration unit. In a calibration mode, the calibration signal generation unit generates an in-phase (I) test signal and a quadrature (Q) test signal. The phase adjusting unit adjusts the I test signal and the Q test signal to generate an adjusted I test signal and an adjusted Q test signal according to a phase controlling signal. The transmission unit generates a radio frequency (RF) signal according to the adjusted I test signal and the adjusted Q test signal. The receiving unit receives the RF signal so as to generate an I receiving signal and a Q receiving signal. The calibration unit generates the phase controlling signal according to the I test signal, the Q test signal, the I receiving signal, and the Q receiving signal.

A translation device, a test system, and a memory system are provided. The translation device includes plural first input/output (I/O) circuits that respectively transmit and receive first signals through plural pins based on a pulse amplitude modulation (PAM)-M mode, a second I/O circuit that transmits and receives a second signal through one or more pins based on a PAM-N mode, and a translation circuit that translates the first signals into the second signal and translates the second signal into the first signals. M and N are different integers of 2 or more.

OFDM-BPSK symbol sequences are used for mutual-coupling based phase array calibration. Such substitution allows phase to be estimated more accurately using a given estimation duration without compromising other estimates' (amplitude and group delay) accuracies.

The disclosed exemplary apparatuses, systems and methods provide at least two realizations of synchronized antenna probe arrays. These antenna probe arrays may be used to generate and receive RF signals in a compact anechoic chamber for over the air antenna testing, or other applications such as far-field antenna test chambers. A compact anechoic chamber for over-the-air antenna testing may include at least: a chamber housing; an interchangeable irradiating test panel, integral to the chamber; a plurality of absorbing material at least partially lining an interior of the chamber and capable of directing the irradiating; at least one moveable cart suitable for moving and removing the antenna from the chamber; at least one panel interface for interconnecting the antenna and equipment for the testing, wherein a response of the antenna to the irradiating is communicated through the panel interface to the testing equipment; and at least one switch matrix for multiplexed switching of ones of signals of the testing.

An echo estimation system includes a transceiver circuitry and a processor circuitry. The processor circuitry is coupled to the transceiver circuitry. The processor circuitry is configured to calculate linear echo power and non-linear echo power based on a signal under test in the transceiver circuitry. The linear echo power and the non-linear echo power are utilized to determine a quality of the transceiver circuitry or utilized to determine component parameters of the transceiver circuitry.

an orthogonal frequency division multiplexed (OFDM) output signal produced by a device in response to an OFDM input signal is accessed. The OFDM input signal includes OFDM input symbols in the time domain and the OFDM output signal includes OFDM output symbols in the time domain. The OFDM output symbols are time-aligned to the OFDM input symbols and a phase of the OFDM output signal is de-rotated with respect to the OFDM input signal. A complex equalization filter is applied to the OFDM output symbols in the time domain to obtain an estimate of the OFDM input symbols A distortion signal of the OFDM output signal is determined by subtracting the estimate of the OFDM input symbols. An error vector magnitude (EVM) is determined by dividing a root mean square of the distortion, by a root mean square of the OFDM input signal.

A cooperative wireless system using a multicast protocol to facilitate coordinating coherent addition and subtraction of wireless signaling or other beams originating from a plurality of antenna units at a target location is contemplated. The system may utilize multicast-based regulation and distribution of transmission control parameters necessary for the antenna units to synchronize the wireless signaling in a manner sufficient to enable the coherent addition and subtraction thereof at the target location.

The present invention relates to an input/output signal synchronization method by a radio frequency unit. The input/output signal synchronization method according to the present invention comprises the steps of: generating a transmitter (Tx) input signal by adding, to a baseband signal, a test signal located at a frequency out of an operation frequency range of the radio frequency unit; collecting the Tx input signal and a Tx output signal obtained by outputting the input signal through a Tx function block; and synchronizing the Tx input signal and the Tx output signals, based on a result obtained by the collecting.