Abstract: Receiving filter design that reduces out-of-channel interference for APs is disclosed. An AP includes a first radio and a second radio disposed in a body of the AP. The first radio transmits first signals in a frequency band while the second radio receives second signals in the same frequency band. The AP includes an interference mitigation controller that determines a receiving filter for the second radio to mitigate interference between the first radio and the second radio based on the second signals received by the second radio when the first radio transmits the first signals in the frequency band. The interference mitigation controller applies the receiving filter to signals received by the second radio during a time period that the first radio is transmitting signals in the frequency band while the second radio is receiving signals in the frequency band.

Abstract: A method is provided in which a first wireless access point selects two or more of a plurality of client devices based on similarity of receive signal strength and carrier frequency offset with respect to the first wireless access point, and sends a downlink multi-user multiple-input multiple-output (MIMO) transmission to the two or more client devices. The downlink multi-user MIMO transmission is configured to solicit acknowledgments from the two or more client devices. The acknowledgments are received at a plurality of antennas of the first wireless access point from the two or more client devices. Uplink multi-user MIMO processing of the acknowledgments is performed from the two or more of the plurality of client devices to recover the acknowledgments respectively from each of the two or more client devices.

Abstract: Embodiments herein describe calibrating a plurality of radio heads having a plurality of wireless antennas. In one embodiment, the plurality of radio heads communicate a calibration signal in a round robin fashion such that each of the radio heads communicates a respective calibration signal to the remaining radio heads. In one embodiment, at least one of the radio heads is isolated from the remaining radio heads. The received calibration signals are then used to calibrate the radio heads. In one embodiment, a controller coupled with the plurality of radio heads calibrates the radio heads. The calibrated radio heads then communicate to one or more client devices.

Abstract: A system and method are provided for performing stomp-and-restart techniques in distributed MU-MIMO system. A plurality of radio head devices are provided that are configured to be deployed separated from each other in a coverage region of interest of a wireless network. A central processor subsystem is provided that is in communication with the plurality of radio head devices. The central processor subsystem configured to perform several operations based on downconverted samples received from the plurality of radio head devices.

Abstract: In one embodiment, an apparatus includes a processor for processing a plurality of radio frequency chains at a wireless device in a block based modulation environment, recording subcarrier phases and differences between the subcarrier phases, and using the subcarrier phase differences to construct a feature vector for use in angle of arrival calculated positioning of a mobile device, and memory for storing the subcarrier phases and the feature vector.

Abstract: An apparatus comprises an antenna array, a block of switches, a programmable logic device and a memory device. The antenna array comprises a plurality of antenna elements. The block of switches is configured to selectively connect respective ones of a subset of the plurality of antenna elements to corresponding ones of a plurality of transceivers in a host device. The programmable logic device is configured to communicate with the host device and to control the block of switches. The memory device is coupled to the programmable logic device, and is configured to store information allowing the host device to determine how to control connectivity of individual antenna elements to respective ones of the plurality of transceivers of the host device as part of transmit and/or receive operations of the host device.

Abstract: A wireless access point device wirelessly communicates with a plurality of wireless client devices. The wireless access point includes a central processor subsystem and a plurality of transceiver devices each including a plurality of antennas, and a plurality of radio transceivers, each of the plurality of transceiver devices configured for deployment throughout a coverage area, each transceiver device being connected to the central processor subsystem via a respective cable. The central processor subsystem distributes in-phase and quadrature baseband samples across the plurality of transceiver devices associated with traffic to be transmitted and received via the plurality of transceiver devices in one or more frequency bands so as to synthesize a wideband multiple-input multiple-output transmission channel and a wideband multiple-input multiple-output reception channel. The access point transmit and receive functions are “split” or partitioned across the plurality of transceivers devices.

Abstract: Access points and a wireless client device, such as a workgroup bridge, are configured to optimize a roaming algorithm of the client device for a high-speed vehicle scenario, such as a high-speed train. A static/dynamic neighbor list is generated and used to improve scanning efficiency. An improved parent access point selection procedure, metrics, and thresholds are provided to optimize client roaming along the vehicle's path, e.g., the train track.

Abstract: A system and method are provided for performing stomp-and-restart techniques in distributed MU-MIMO system. A plurality of radio head devices are provided that are configured to be deployed separated from each other in a coverage region of interest of a wireless network. A central processor subsystem is provided that is in communication with the plurality of radio head devices. The central processor subsystem configured to perform several operations based on downconverted samples received from the plurality of radio head devices.

Abstract: In one embodiment, an apparatus includes a plurality of antennas, a receiver in communication with said plurality of antennas for receiving one or more packets in a block based modulation environment, a switch interposed between a portion of the antennas and the receiver for switching between the antennas, and a processor for calculating angle of arrival for use in identifying a location of a mobile device transmitting the one or more packets.

Abstract: Techniques are presented herein for improving location determination of a wireless device in environments where there can be multipath issues. A wireless device having a plurality of antennas receives a wireless transmission from a target device whose location is to be determined. Channel state information data is generated based on reception of the transmission at the plurality of antenna. The channel state information data is separated or partitioned into subcarrier group specific data for each of a plurality of groups of subcarriers within a bandwidth of the received transmission. Location probability data is computed for each of the plurality of groups of subcarriers from the subcarrier group specific data for respective ones of the plurality of groups of subcarriers. The location probability data for the plurality of groups of subcarriers is combined to produce aggregate location probability data, from which a location of the target device is determined.

Abstract: Noise floor degradation detection may be provided. First, an incremental packet loss rate for a secondary radio may be calculated that indicates an impact on packet reception on the secondary radio due to transmissions by a primary radio. The secondary radio and the primary radio may comprise an access point. Next, it may be determined that the incremental packet loss rate is greater than a predetermined value. A configuration of the access point may be changed in response to determining that the incremental packet loss rate is greater than the predetermined value.

Abstract: A system and method are provided for performing stomp-and-restart techniques in distributed MU-MIMO system. A plurality of radio head devices are provided that are configured to be deployed separated from each other in a coverage region of interest of a wireless network. A central processor subsystem is provided that is in communication with the plurality of radio head devices. The central processor subsystem configured to perform several operations based on downconverted samples received from the plurality of radio head devices.

Abstract: Apparatus and techniques are presented for estimating a noise floor experienced by a client device seeking to associate with an access point in a wireless network. A path loss between the client device and the access point may be estimated. A metric may then be generated, where the metric estimates a strength of a signal transmitted from the access point as received at the client device. The transmit power at the access point may then be adjusted, based on the metric.

Abstract: A plurality of time slots are allocated during which a location procedure is performed for one or more target wireless devices. Select ones of a plurality of wireless access points at different positions are assigned to each time slot such that multiple wireless access points assigned to a given time slot are sufficiently separated. In addition, wireless access points are assigned to a corresponding one of a plurality of groups for each time slot such that wireless access points assigned to a group tune to a channel used by a wireless access point in the group that transmits one or more frames that are intended to provoke one or more response frames from the one or more wireless devices.

Abstract: A method is provided in which a first wireless access point selects two or more of a plurality of client devices based on similarity of receive signal strength and carrier frequency offset with respect to the first wireless access point, and sends a downlink multi-user multiple-input multiple-output (MIMO) transmission to the two or more client devices. The downlink multi-user MIMO transmission is configured to solicit acknowledgments from the two or more client devices. The acknowledgments are received at a plurality of antennas of the first wireless access point from the two or more client devices. Uplink multi-user MIMO processing of the acknowledgments is performed from the two or more of the plurality of client devices to recover the acknowledgments respectively from each of the two or more client devices.

Abstract: In accordance with an embodiment, a method is provided in which a first wireless access point sends a downlink multi-user multiple-input multiple-output (MIMO) transmission to a plurality of client devices. The downlink multi-user MIMO transmission is configured to solicit acknowledgments from two or more of the plurality of client devices. The acknowledgments are received at a plurality of antennas of the first wireless access point from the two or more of the plurality of client devices. Uplink multi-user MIMO processing of the acknowledgments is performed from the two or more of the plurality of client devices to recover the acknowledgments respectively from each of the two or more of the plurality of client devices.

Abstract: In accordance with an embodiment, a method is provided in which a first wireless access point sends a downlink multi-user multiple-input multiple-output (MIMO) transmission to a plurality of client devices. The downlink multi-user MIMO transmission is configured to solicit acknowledgments from two or more of the plurality of client devices. The acknowledgments are received at a plurality of antennas of the first wireless access point from the two or more of the plurality of client devices. Uplink multi-user MIMO processing of the acknowledgments is performed from the two or more of the plurality of client devices to recover the acknowledgments respectively from each of the two or more of the plurality of client devices.

Abstract: A set of receiver path circuits is allocated for processing a radio-frequency (RF) signal provided by receive antennas coupled to the receiver path circuits. The RF signal may belong to a first signal class, such as Wi-Fi. A first gain control signal is applied to each of the allocated receiver path circuits to condition a signal level of the RF signal for the first signal class. A second gain control signal is applied to another set of receiver path circuits coupled to the receive antennas to condition the RF signal of a second signal class. First receive gain control signals are generated from the RF signals of the first signal class by the allocated set of the receiver path circuits. The first receive gain control signals are configured to optimize the signal level for processing the first signal class. A second receive gain control signal is generated to optimize the signal level of the RF signal for the second signal class.

Abstract: A particular first wireless device having a plurality of antennas and that is part of a group of a plurality of first wireless devices, transmits to a second wireless device (whose location is to be determined) a packet across the plurality of antennas of the particular first wireless device simultaneously with a plurality of packets transmitted by a corresponding one of other first wireless devices in the group. The packet transmitted by the particular first wireless device uses a subset of a set of subcarriers available for use in the packet such that substantially the entire set of subcarriers are used in the aggregate across the plurality of packets simultaneously transmitted by the plurality of first wireless devices in the group to the second wireless device. The simultaneous reception of the plurality of packets at the second wireless device enables the second wireless device to determine its location.