A method is provided for generating test data for testing radio equipment. The method includes: determining, by a test apparatus, one or more beam identifiers; selecting, by the test apparatus, based on the one or more beam identifiers, one or more radio channel models; receiving, by the test apparatus, a baseband signal representing I/Q data of one or more beamforming antennas; processing, by the test apparatus, the baseband signal representing I/Q data according to the selected radio channel model; and transmitting, by the test apparatus, the processed baseband signal representing I/Q data to a radio equipment under test.

A transmission method of simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals. One of signal generation processing in which phase change is performed and signal generation processing in which phase change is not performed is selectable, thereby improving general versatility in signal generation.

Embodiments of the present disclosure relate to a method and an apparatus for antenna calibration. A method performed by an apparatus for antenna calibration may comprise: inserting a calibration signal to a physical resource block allocated for a traffic signal; and distinguishing the calibration signal from the traffic signal at a calibration receiver for antenna calibration. According to embodiments of the present disclosure, antenna calibration signals and traffic signals may be transmitted simultaneously.

A test system for testing a device under test is described. The test system includes a testing circuit and the device under test. The testing circuit is configured to establish a wireless connection with the device under test based on a wireless communication standard having a low energy protocol. The wireless connection includes a plurality of channels, wherein the plurality of channels is configured to transmit data packages between the testing circuit and the device under test. The testing circuit and the device under test are configured to communicate with each other via the plurality of channels by a channel hopping technique. A radio frequency (RF) level of a signal transmitted by the testing circuit in at least one test channel to be tested, which belongs to the plurality of channels, is lower than an RF level of a signal transmitted by the testing circuit in at least one other channel of the plurality of channels. Further, a test method of testing a device under test is described.

A test instrument for providing an optics troubleshooting technique of an optical transceiver is disclosed. The test instrument may comprise a processor and a memory, which when executed by the processor, performs the optics troubleshooting technique. The optics troubleshooting technique may include identifying a test signal from the optical transceiver. The optics troubleshooting technique may include determining signal power associated with the signal. The optics troubleshooting technique may further include applying one or more expert mode settings. In some examples, the one or more expert mode settings may be applied in a predefined order until an acceptable BER result is achieved over a predefined test period. In this way, test instrument may determine which of the one or more expert mode settings is responsible for the acceptable BER result.

A method, system, and apparatus for emulating impairments in a communication system.

A method for testing terminals includes determining a quantity of terminals to be tested; testing each terminal to be tested in a testing environment and obtaining a quantity of testing results; each testing result includes an actual transmitting power and/or a receiving signal strength; obtaining a first fitting function based on the actual transmitting power, and/or obtaining a second fitting function based on the receiving signal strength; and controlling a target terminal to transmit signals, calculating an actual transmitting power of the target terminal by the first fitting function, and/or controlling the target terminal to receive signals, calculating a receiving signal strength of the target terminal by the second fitting function. A computer apparatus and a non-transitory computer readable medium for testing terminals are also disclosed.

The computer-implemented method includes simulating, by a processor, using an electromagnetic solver including ray launching or ray tracing, multiple rays that reach a vicinity of a receiver of a wireless channel, determining locations of interactions of the rays with an environment of the wireless channel, post-processing, using one or more of the multiple rays, information about received signal at the receiver to obtain temporal variations therein, and determining a characteristic of the wireless channel using results of the post-processing.

The computer-implemented method includes simulating, by a processor, using an electromagnetic solver including ray launching or ray tracing, multiple rays that reach a vicinity of a receiver of a wireless channel, determining locations of interactions of the rays with an environment of the wireless channel, post-processing, using one or more of the multiple rays, information about received signal at the receiver to obtain temporal variations therein, and determining a characteristic of the wireless channel using results of the post-processing.

In the field of communications assemblies, particularly those arising in connection with high voltage direct current (HVDC) power converters, there is provided a communications assembly (10) that comprises a first module (12) which is arranged in operative communication with a second module (14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H) via a communication conduit (16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H). At least one of the first module (12) and the second module (14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H) have a receiver (24) that includes a squelch filter (26) which is configured to operate in a first normal mode and a second test mode. The squelch filter (26) normally operates in the first normal mode to suppress a signal output (28) from the receiver (24) when the strength of an input signal (30) received by the receiver (24), via the communication conduit (16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H), falls below a normal threshold. The squelch filter (26) selectively operates in the second test mode to suppress the signal output (28) from the receiver (24) when the strength of the input signal (30) received by the receiver (24), via the communication conduit (16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H), falls below a test threshold higher than the normal threshold. When the squelch filter (26) is operating in the second test mode, a signal output (28) from the receiver (24) indicates a signal margin in the communication conduit (16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H) that is at least equal to the difference between the test threshold and the normal threshold.