Abstract: Bus enumeration of a switch fabric bus may be performed without assigning bus numbers to unused switch ports and/or corresponding slots to which the unused switch ports are routed. Accordingly, switches coupled to a switch fabric bus in a chassis may link-train with corresponding slots in the chassis in an attempt to establish active connections with devices coupled to the slots. Unused switch fabric bus lanes running from the switches to unused slots may be identified, and the unused switch ports corresponding to the unused switch fabric bus lanes may be disabled. During a subsequent bus enumeration procedure for the switch fabric bus, bus numbers may be allocated to the identified used switch ports (or corresponding used slots) but not to the identified unused switch ports (or corresponding unused slots). The link training, used/unused switch port identification, and bus enumeration may all be performed each time the chassis is reset.

Abstract: Methods and measurements systems are disclosed relating to dynamic measurement prioritization by multiple software interfaces. A first software interface with a low priority may be conducting a first measurement on a device under test (DUT) through a driver connected to a measurement device. A second software interface with a higher priority may initiate a request to conduct a second measurement on the DUT. In response, the driver may automatically determine that the second software interface has a higher priority than the first software interface and may halt the first measurement and conduct the second measurement. The driver may notify the first software interface that its access to the measurement hardware has been revoked, and the first software interface may enter a monitoring mode to monitor the results of the second measurement.

Abstract: Methods and measurements systems are disclosed relating to use of a soft front panel (SFP) to display results of measurement functions. A measurement device may concurrently perform two or more measurement functions to produce two or more respective signal measurements, wherein each measurement function comprises an acquisition function and a processing function. A computer may be configured to display information on a soft front panel on the display device corresponding to two or more of the signal measurements. The computer may receive, from a user, a selection of an update option, wherein the update option indicates a trigger that causes the displayed information to update. Responsive to receiving an indication that the trigger has occurred, the computer may update the displayed information on the soft front panel.

Abstract: A wireless cellular base station (BS) transmitter transmits a downlink calibration pilot symbol. A receiver receives from a user equipment (UE) an uplink calibration pilot symbol and an effective downlink channel estimate transmitted by the UE. The effective downlink channel estimate is computed by the UE using the downlink calibration pilot symbol received from the BS. Processing devices compute an effective uplink channel estimate using the uplink calibration pilot symbol received from the UE and compute channel reciprocity calibration coefficients using the effective downlink channel estimate received from the UE and the effective uplink channel estimate computed by the BS. The BS includes multiple antennas, and the BS computes the channel reciprocity calibration coefficients for each antenna. Alternatively, the uplink channel estimate received by the BS is an inverted version of the effective downlink channel estimate, which the processing devices use for channel reciprocity compensation.

Abstract: A base station (BS)/user equipment (UE) for performing radio frequency beam management and recovery in communication with a UE/BS. The BS/UE includes a processor and a memory that stores first and second thresholds. The processor evaluates a beam quality metric against the first and second thresholds, performs beam switching and/or beam broadening in response to determining the beam quality metric falls below the first threshold, and performs a beam failure recovery procedure in response to determining the beam quality metric falls below the second threshold.

Abstract: Antenna characterization systems and methods are described for hardware-timed testing of integrated circuits (IC) with integrated antennas configured for over-the-air transmission and/or reception. An IC to be tested (e.g., the device under test (DUT)) may be mounted to an adjustable positioner in an anechoic chamber. Radio frequency (RF) characteristics (e.g., including transmission characteristics, reception characteristics, and/or beamforming characteristics) of the IC may be tested over-the-air using an array of antennas or probes within the anechoic chamber while continually transitioning the adjustable positioner through a plurality of orientations. Counters and reference trigger intelligence may be employed to correlate measurement results with orientations of the DUT.

Abstract: Systems and methods are described for using a single wideband pilot signal to reduce a timing misalignment between receivers in a multiple-input multiple-output (MIMO) radio system. The multiple generators of the MIMO radio system may be aligned using a second wideband pilot signal subsequent to performing the receiver alignment. The calibration kit of the MIMO radio system may be aligned using a third wideband pilot signal prior to performing the receiver alignment. Alignment may be achieved to subsample precision by determining time delays from the rate of change of the phase shift of the wideband pilot signals.

Abstract: A novel coupling system may include a head-end circuit for coupling a probe via a cable to an instrument, delivering power to the probe over the cable while the cable carries signal(s) from the probe to the instrument. The head-end circuit may include a first terminal for coupling to the probe via a cable, and may further include a second terminal for coupling to the instrument. The head-end circuit may apply direct-current (DC) power to the cable, and may remove a DC voltage offset resulting from the applied DC power before a signal from the probe reaches the instrument. The head-end circuit may include a common node coupled to the first terminal, a current source coupling the common node to a supply voltage, and a voltage source coupling the common node to a second terminal that couples to the instrument.

Abstract: Techniques are disclosed relating to a massive MIMO base station architecture. In some embodiments, a base station is configured to combine signals received by multiple antennas and, for at least a subset of processing elements included in the base station, each processing element is configured to operate on a different portion of the combined signals. In these embodiments, each portion includes signals from multiple antennas. In some embodiments, the portions are different time and/or frequency portions of the combined signals. In some embodiments, this distributed processing may allow the number of antennas of the base station to scale dramatically, provide dynamic re-configurability, facilitate real-time reciprocity-based precoding, etc.

Abstract: A base station receives a report of channel state information (CSI) computation capability from a UE, configures the UE with X and Y values based on the reported computation capability, performs a beam sweep by transmitting direction-unique beams, and receives a beam measurement report from the UE comprising a reference signal receive power (RSRP) of Y strongest beams of the transmitted beams and at least a portion of the CSI of X strongest beams of the Y beams. Based on the beam measurement report, one of the X beams is selected to configure the UE for subsequent data and control channel transmissions. X and Y are positive integers, Y is greater than or equal to X, and Y is at least 1.

Abstract: An apparatus to transmit and receive wireless communications is disclosed in which the transmit circuitry includes a square root raised cosine filter to pulse shape modulate signals and the receive circuitry includes a higher order Nyquist receive filter coupled to receive the input signals and remove the pulse shaping modulation. The cascaded combination of the transmit and receive filters has a frequency response equivalent to a higher order generalized raised cosine filter response.

Abstract: Techniques are disclosed related to determining a modulation quality measurement of a device-under-test (DUT). A modulated signal is received from a source a plurality of times, and each received modulated signal is transmitted to each of a first vector signal analyzer (VSA) and a second VSA. The first VSA and the second VSA demodulate the received modulated signals to produce first error vectors and second error vectors, respectively. A cross-correlation calculation is performed on the first error vectors and second error vectors of respective received modulated signals to produce a cross-correlation measurement, and the cross-correlation measurement is averaged over the plurality of received modulated signals. A modulation quality measurement is determined based on the averaged cross-correlation measurement.

Abstract: A method and apparatus for simultaneously testing a component at multiple frequencies is disclosed. A digital processing circuit may generate a digital representation of a signal having a plurality of sine waves, each having a unique frequency. The digital representation may be converted into an analog signal, and applied to a device under test (DUT). A first analog-to-digital converter (ADC) may be coupled to measure voltages across the DUT, while a second ADC may be coupled to measure currents through the DUT. Voltage and current signals received by the first and second ADCs, respectively, may be converted into first and second digital values. Voltage and current values at each unique frequency are determined from the first and second digital values. Using the voltage and current values for each unique frequency, a frequency response of the component (e.g., an impedance) over a range of frequencies may be determined.

Abstract: Various embodiments are presented of a system and method for testing (e.g., rapidly and cheaply) devices with antennas configured for radio frequency (RF) and/or millimeter wave (mmW) transmission and/or reception. A device to be tested (e.g., the device under test (DUT)) may be mounted to an interface in a measurement fixture (e.g., a socket, anechoic chamber, etc.). Power and data connections of the DUT may be tested over the interface, which may also provide connections for input/output signals, power, and control and may also provide positioning. RF characteristics (e.g., including transmission, reception, and/or beamforming) of the DUT may be tested over-the-air using an array of antennas or probes.

Abstract: To perform system level physical connectivity monitoring measurements, a test signal may be generated in an instrument and transmitted down a signal path extending from the instrument to a device. In a static state (high or low), the test signal generator may produce a specified AC impedance at the point where the signal path connects to the instrument for a designated back termination. A response signal resulting from the test signal may be acquired and used to obtain an impedance value and/or reflection coefficient value representative of the signal path and an additional signal path extending from the source of the test signal to the signal path. The measured response may be compared to an expected response to determine a condition of any component(s) in the signal path and/or in the additional signal path. The expected response may be represented by masks (low and high) created during automated test development.

Abstract: Antenna characterization systems and methods are described for hardware-timed testing of integrated circuits (IC) with integrated antennas configured for over-the-air transmission and/or reception. An IC to be tested (e.g., the device under test (DUT)) may be mounted to an adjustable positioner in an anechoic chamber. Radio frequency (RF) characteristics (e.g., including transmission characteristics, reception characteristics, and/or beamforming characteristics) of the IC may be tested over-the-air using an array of antennas or probes within the anechoic chamber while continually transitioning the adjustable positioner through a plurality of orientations. Counters and reference trigger intelligence may be employed to correlate measurement results with orientations of the DUT.

Abstract: Techniques are disclosed relating to channel sounding. In some embodiments a transmitter transmits a periodic CAZAC sequence beginning at a point in time that corresponds to a timing signal (e.g., a pulse-per-second signal). In some embodiments, a receiver waits to begin processing received sequences for a time interval corresponding to the length of the CAZAC sequence, where the time interval begins at the same time as the timing signal. This may avoid a need for timing synchronization prior to processing, reduce processing and latency in receiver implementations, and may allow determination of a TOA as well as a channel impulse response estimate by correlating a received cyclically-shifted CAZAC sequence with a local version of the transmitted CAZAC sequence.

Abstract: A base station (BS) having a plurality of antennas transmits a plurality of spatial streams. Each user equipment (UE) of a plurality of UE estimates common phase error (CPE) of each of two or more of the plurality of spatial streams, measures correlations of the estimated CPE among the two or more of the plurality of spatial streams, and provides feedback about the CPE correlations to the BS. The BS uses the CPE correlation feedback to allocate phase tracking reference signal (PTRS) ports and to map the allocated PTRS ports to demodulation reference signal (DMRS) ports corresponding to the plurality of spatial streams.

Abstract: Hardware may be created with different clock speeds used for different components of the system. Clock and throughput requirements on the interface circuitry of hardware components may set limits which are lower requirements for functional components. It may be advantageous to use more or fewer of some functional blocks or interface circuits in order to reduce cost, increase performance or reliability, reduce the requirements for additional parts, or other beneficial factors. Accordingly, it may be advantageous to generate hardware utilizing more than a single clock frequency. Generating instructions which indicate different clock frequencies for separate components may be difficult or time consuming; generating these instructions automatically may provide significant benefits in time savings, increased productivity, increased performance of hardware, or other benefits.

Abstract: Embodiments are described of devices and methods for processing a signal using a plurality of vector signal generators (VSGs). A digital signal may be provided to a plurality of signal paths, each of which may process a respective frequency band of the signal, the respective frequency bands having regions of overlap. The gain and phase of each signal path may be adjusted such that continuity of phase and magnitude are preserved through the regions of overlap. The adjustment of gain and phase may be accomplished by a complex multiply with a complex calibration constant. The calibration constant may be determined for each signal path by comparing the gain and phase of one or more calibration tones generated within each region of overlap. Each signal path may comprise a VSG to convert the respective signal to an analog signal, which may be combined to obtain a composite signal.