National Instruments Corporation

Achim Nahler

Nikhil U Kundargi

James Wesley McCoy

Amal Ekbal

Michael Löhning

Max Koehler

Rohit Gupta

A UE transmits to a BS an indication of a number of PTRS ports. The number of PTRS ports is a suggestion to the BS for allocating the indicated number of PTRS ports to the UE for transmission of PTRS from the BS to the UE to enable the UE to perform phase tracking. The method also includes allocating, by the BS, PTRS ports to the UE based on the indication of the number of PTRS ports. The indication may be included in a UCI message, MAC CE, or RRC message transmitted by the UE to the BS. The BS may map the allocated PTRS ports to DMRS ports corresponding to spatial streams transmitted by the BS. The UE may estimate CPE of each spatial stream, measure correlations of the estimated CPE among the spatial streams, and use the correlations to determine the suggested number of PTRS.

Wireless communication system that performs measurement based selection of phase tracking reference signal (PTRS) ports

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.

Radio frequency beam management and recovery

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.

Wireless communication system that performs beam reporting based on a combination of reference signal receive power and channel state information metrics

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.

A base station radio transceiver transceives beams with a UE. In a first beam set of wide beam reference signals (RS), each wide beam RS direction is unique, and in a second beam set of narrow beam RS, each narrow beam RS direction is unique and the width of the narrow beam RS is narrower than the width of the wide beam RS. A linkage uniquely links each narrow beam RS to a wide beam RS. The direction of each narrow beam RS is spatially nested within the width of the wide beam RS to which it is uniquely linked. A processor uses the first and second beam sets in a beam management process in which one of the narrow beam RS is selected for the UE and the wide beam RS uniquely linked to the selected narrow beam RS is selected for the UE according to the linkage.

Wireless communication system that performs beam management using nested reference signals

A processor in a UE evaluates a radio frequency beam quality metric against a threshold, switches from a first beam to a second beam in response to determining the metric falls below the threshold, and transmits to a base station (BS) a report that includes beam measurements. The report indicates the UE has performed the switching and that the beam measurements are with respect to the second beam. A processor in a UE/BS associates narrower and broader beams, uses the narrower beam, rather than the broader beam, to transfer user data between the BS and the UE, evaluates a beam quality metric of the narrower beam against the threshold, and switches to using the broader beam, rather than the narrower beam, to transfer user data between the BS and the UE in response to determining the beam quality metric of the narrower beam falls below the threshold.

Radio frequency beam management and failure pre-emption

A wireless device receives a frequency division multiplexed (FDM) symbol of constituent equalized FDM data subcarriers. A modulation scheme constellation diagram is subdivided into two or more regions. For each of the regions, a subset of the subcarriers that fall within the region are extracted and a respective region-specific CPE estimate is computed thereon. The respective region-specific CPE estimates are averaged to produce an overall CPE estimate used to compensate the subcarriers. Furthermore, a first CPE estimate is computed using pilot symbols embedded in a first received FDM symbol and is used to compensate the subcarriers. A following second FDM symbol that has no embedded pilot symbols is compensated using the first CPE estimate, and a second CPE estimate is computed using a blind estimation method on the second FDM symbol compensated subcarriers, which are compensated using the second CPE estimate.

Common phase error (CPE) compensation for frequency division multiplex (FDM) symbols in wireless communication systems

An apparatus includes circuitry that processes a subframe as part of a time-domain signal frame structure used for radio frequency communications. The subframe includes a plurality of block symbols each having an associated time-domain guard period and one or more radio frequency (RF) switching guard periods. Each block symbol of the plurality of block symbols is either a common block symbol or a special block symbol. A common block symbol has a common time-domain guard period with all other common block symbols of the subframe. A special block symbol has a time-domain guard period different from the common time-domain guard period. All the special block symbols in the subframe are placed into the one or more RF switching guard periods.

Radio frequency (RF) communication systems using RF switching guard periods to transmit special symbols in block symbol transmissions

Techniques are disclosed relating to detection of wireless signals. In some embodiments, a method includes generating an autocorrelation result for a training field in a received wireless message, generating differentiation information based on the autocorrelation result, and determining that one or more signal recognition criteria are met. In some embodiments, the signal recognition criteria include a first criterion that a first peak in the differentiation information satisfies a first threshold for at least a first time interval. In some embodiments, the signal recognition criteria include one or more additional criteria, including a second criterion that a second peak in the differentiation information satisfies a second threshold for at least a second time interval, wherein the first and second peaks have different polarities and/or a third criterion that the first peak corresponds to an autocorrelation result value that is below a particular autocorrelation threshold.

Method and apparatus for improved Schmidl-Cox-based signal detection

A communication device and associated method which is configured to utilize an API constraint language for communication of resource constraints between different layers of a communication stack. A first layer of the communication stack executing in a first communication device may receive application programming interface (API) messages from a second layer of the communication stack also executing in the first communication device. In addition, the first layer may receive resource constraints with the one or more API messages. These one or more resource constraints may be generated by the second layer, or other software executing in the communication device. The first layer may then execute communication functions based on the API messages and subject to the resource constraints. The resource constraints may affect usage of hardware and/or software resources of the first communication device during execution of the communication functions.

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Dresden, Germany

Achim Nahler