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.

This disclosure provides systems, methods, and apparatus for link adaptation in a wireless local area network (WLAN). A link adaptation test packet from a first WLAN device to a second WLAN device may be formatted as a multiple-input-multiple-output (MIMO) transmission and may include one or more test portions for link quality estimation of the MIMO transmission. A link quality estimation portion of the test packet may permit measurement of link quality for various spatial streams of the MIMO transmission. The link adaptation test packet may enable a fast rate adaptation of a communication link based on the impact of interference to the various spatial streams. The second WLAN device may provide feedback information regarding the one or more test portions. The feedback information may be used to determine a transmission rate for a subsequent transmission from the first WLAN device to the second WLAN device based on wireless channel conditions.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a testing equipment may transmit a set of test signals to a device under test (DUT) from a plurality of directions relative to the DUT; obtain, from the DUT, a set of measured multiple-input multiple-output (MIMO) sensitivity results based at least in part on the set of test signals; and determine a MIMO over the air (OTA) performance of the DUT based at least in part on a single measured MIMO sensitivity result of the set of measured MIMO sensitivity results or an average of MIMO sensitivity results, in a subset of the set of measured MIMO sensitivity results, that satisfy a threshold percentile. Numerous other aspects are provided.

An apparatus including a contactor having a hole and including a radio frequency absorptive material and a probe inserted in the hole to couple a test signal to a device under test is disclosed. A test system for testing integrated circuits including a contactor including a radio frequency absorptive material is disclosed. A method for making the contactor is also disclosed.

A near-field test system for a phased array antenna includes a probe, a beam forming network, and a computing system. The probe is disposed at a fixed position in a near-field of the phased array antenna and transmits a test beam toward a fixed location on the phased array. The beam forming network is coupled to the phased array and includes a plurality of phase shifters and a beam summer. The phase shifters steer received beams for each antenna element of the phased array to form a planar wave front. The beam summer is coupled to the phase shifters and combines power of the received beams. The computing system is coupled to the beam forming network and scales combined power of the received beams and generates a virtual spectrum for the phased array antenna from scaled power of the received beams.

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.

A device, comprising a packet data interface port; a microcontroller, configured to control the packet data interface port, receive a input control signal through the packet data interface port, transmit a status report through the packet data interface port, and in dependence on the input control signal, produce an output control signal; and a radio frequency modification device, configured to modify a received radio frequency signal over a range selectively in dependence on the output control signal. A control processor, communicating through the packet data interface port with the microcontroller, may generate a plurality of the input control signals for a plurality of respective devices comprising the microcontroller and the radio frequency signal control device. The input control signals may be dynamically changed over time to emulate radio frequency conditions resulting from mobility of nodes in a mobile ad hoc radio frequency communication network.

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