Abstract: A communication device receives a physical layer (PHY) data unit that includes i) a first orthogonal frequency division multiplexing (OFDM) symbol corresponding to a legacy signal field of a PHY preamble, and ii) a second OFDM symbol that immediately follows the first OFDM symbol. The communication device determines a first bit sequence corresponding to the first OFDM symbol and a second bit sequence corresponding to the second OFDM symbol. The communication device unscrambles the second bit sequence to obtain an unscrambled second bit sequence, and determines whether the unscrambled second bit sequence matches the first bit sequence. If the unscrambled second bit sequence matches the first bit sequence, the communication device decodes the PHY data unit according to a first communication protocol, and if the unscrambled second bit sequence does not match the first bit sequence, decodes the PHY data unit according to a second communication protocol.

Abstract: A communication device of a first wireless network determines that a first value of a first basic service set (BSS) color identifier is the same as a value of a second BSS color identifier corresponding to a neighboring second wireless network. In response, the communication device determines a second value of the first BSS color identifier. The communication device transmits one or more packets that each include i) an indication that the first BSS color identifier is changing, ii) the second value of the first BSS color identifier, and iii) a respective integer number of remaining beacon intervals corresponding to a start time when the second value of the first BSS color identifier will supersede the first value of the first BSS color identifier. Based on the start time, the communication device begins to use the second value of the first BSS color identifier with communications in the first wireless network.

Abstract: The present disclosure includes systems and techniques relating to controlling access to a shared communication medium in a wireless communication system. In some implementations, a first communication device associated with a first basic service set (BSS) identified by a first BSS indicator receives a data unit transmitted by a second communication device. The data unit includes (i) a second BSS indicator indicating a second BSS associated with the second communication device and (ii) a duration indicator indicating a duration of time for which the shared communication medium is expected to be busy. An inter-BSS channel access counter is set based on the duration of time indicated by the duration indicator if the second BSS is different from the first BSS. An intra-BSS channel access counter is set based on the duration of time indicated by the duration indicator if the second BSS is the same as the first BSS.

Abstract: Systems and methods are provided for mitigating image noise. Portion motion vectors are identified for a plurality of portions of a first frame relating to a setting, the portion motion vectors indicating motion from the first frame to a second frame. A global motion vector is determined that indicates global motion spanning the first frame to the second frame. A determination is made that a first portion of the plurality of portions has a portion motion vector that is consistent with the global motion vector. Motion compensation is performed on the first frame and the second frame to align the second frame with first frame at the first portion that is consistent with the global motion vector to generate an output image that is based on both of the two frames. An inconsistent second portion of one of the frames is incorporated into the output image.

Abstract: Embodiments described herein methods and systems for channel correlation based user detection in an uplink multiuser transmission of a multiple-input multiple-output (MIMIO) network. In some embodiments, the channel correlation based user detection may be used in 802.11 UL MUMIMO systems. For example, an access point may detect whether a client station responds to a trigger frame and then adjust a channel matrix accordingly to reflect whether the client station is responsive. The access point may then decode received data signals based on the adjusted channel matrix that reflects whether a client station has transmitted.

Abstract: Apparatus, methods, and other embodiments associated with debugging a device-under-test are disclosed. In one embodiment, a method includes sensing and recording a screen image produced by a device-under-test as the device-under-test is being operated. The sensing and recording of the screen image are performed by an apparatus. The method also includes sensing and recording coordinates and durations of gestures impinged upon the apparatus while operating the device-under-test. The sensing and recording of the coordinates and durations are performed by the apparatus. The apparatus is configured to physically conform to the device-under-test to allow functionality of the device-under-test through the apparatus.

Abstract: A clock and data recovery (CDR) circuit operates to recover a clock and sample data from full-rate and sub-rate data signals. The CDR circuit selectively shifts one or more of the sampling clocks based on the rate of a received data signal, facilitating accurate sampling of sub-rate data signals. A masking circuit selectively masks data output bits clocked by a selection of the sampling clocks, thereby outputting relevant sampled data.

Abstract: A first communication device generates a packet associated with acknowledgment of frames corresponding to multiple second communication devices. Generating the packet includes generating a frame that includes a field having respective acknowledgment information for the multiple second communication devices in respective subfields. The subfields have a plurality of different formats. The subfields are arranged within the field in groups of adjacent subfields such that each group includes only subfields of a same format and/or includes only subfields corresponding to second communication devices that have communicated to the first communication device a same set of supported formats of the subfields. The first communication device transmits the packet to the multiple second communication devices.

Abstract: The present disclosure describes apparatuses and methods of interference cancellation for receivers with multiple antennas. In some aspects, an interference packet transmitted by an interfering device of a wireless environment is received via multiple antennas of a device. Based on the interference packet, an interference channel that describes interference in the wireless environment is estimated. The device then receives an intended packet through the wireless environment in which the interfering device is operating. At least a portion of interference received with the intended packet, such as interference caused by other interfering packets, is cancelled using the interference channel. By so doing, a receiver may reduce effects of interfering packets or signals of the wireless environment to improve receive performance (e.g., bit-error rate) for packets that are intended for reception by the device.

Abstract: Methods, systems, and apparatus for detecting poor Doppler measurements results in GNSS navigation, in one aspect, a method including: calculating a first Doppler shift value, wherein the first Doppler shift value is based on movement of a Global Navigation Satellite System (GNSS) receiver and calculated according to a Doppler measurement result; calculating a second Doppler shift value, wherein the second Doppler shift value is based on movement of the GNSS receiver and calculated according to a projection of velocity of the GNSS receiver on a line of sight (LOS) vector; comparing the first Doppler shift value with the second Doppler shift value to check an accuracy of the Doppler measurement result; and determining at least a direction of movement of the GNSS receiver in accordance with the checked accuracy of the Doppler measurement result.

Abstract: The present disclosure includes apparatus, systems, computer readable storage media and techniques relating to virtualization of data storage space. In one aspect, a method performed by a data processing device includes identifying a subset of physical disks within a node. The identified subset includes at least one of the physical disks having at least one subdisk with free storage space. The node includes processing units and the physical disks arranged to form at least one group. A priority value is assigned to the identified subset of the physical disks. The identified subset of the physical disks is sorted based on the assigned priority value, and subdisks are selected from the sorted subset of the physical disks to form a logical disk.

Abstract: A network device activates an alternative path flow control for spanning tree protocol. The network device includes a receiver that receives first network traffic from a first transmitter of the first network traffic, the first network traffic being destined for a first receiver along a first network path, and receives second network traffic from the first receiver, the second network traffic being destined for at least the first transmitter along a second network path. The network device also has a pause frame detector configured to detect in the second network traffic a pause frame for controlling a flow of the first network traffic. The network device, furthermore, has an alternative network path activator configured to activate, a third network path that is different from the first network path, for transmitting the first network traffic to the first receiver.

Abstract: The present disclosure describes methods and apparatuses for matrix compensation to prevent rank deficiency. In some aspects, a channel matrix is formed based on channel feedback matrices that are received from multiple devices. The channel matrix is transformed to provide a channel covariance matrix, which is then decomposed into a unitary matrix and Eigen value matrix components. Diagonal values of the Eigen value matrix are increased to provide a compensated Eigen value matrix. Based on the compensated Eigen value matrix, a steering matrix is determined for steering transmissions through the channel to the multiple devices. By compensating the Eigen value matrix, rank deficiency issues that typically result in failed steering matrix calculations can be prevented. Alternately or additionally, a dynamic range of the steering matrix calculations may be reduced by compensating matrices, enabling steering matrices to be calculated with less-complex or fewer hardware resources.

Abstract: Accordingly, systems and methods for managing power when the number of training and data tones are increased in a wireless communications system are provided. An L-SIG field is generated that includes a set of data and pilot tones, wherein the pilot tones are inserted between the data tones in the set of data and pilot tones. A plurality of training tones is added to the L-SIG field before and after the set of data and pilot tones. A symbol is generated that includes the L-SIG field, an L-LTF field, and a data field, wherein the training tones of the L-SIG field provide channel estimates for the data field. Power of the L-LTF field is managed relative to power of the L-SIG field in the generated symbol in a time domain.

Abstract: A circuit includes an instruction scheduling circuit and an instruction buffer including entries. The entries each include an instruction, a validity indication, and an attribute. The instruction scheduling circuit partitions the entries into first sets, determines second sets by reordering the entries of each first set according to their attributes, determines a set ordering for the first sets according to a function of their attributes, and selects, based on the set ordering, instructions from the second sets. A process for selecting instructions to issue receives entries, each entry including an instruction, a validity indications, and an attribute. The process partitions the entries into first sets, determines second sets by reordering the entries of each first set according to their attributes, determines a set ordering for first sets according to a function of the attributes of their entries, and selects, based on the set ordering, instructions from the second sets.

Abstract: A first format according to which a PHY data unit is to be generated is selected. The data unit is generated according to the first format, including generating a PHY preamble of the PHY data unit to include a first field and a second field. The PHY preamble is generated so that one or more OFDM symbols are rotated by 90 degrees with respect to other OFDM symbols in the PHY preamble to signal the first format. Or, the first field is generated to include a set of bits that according to an error detection scheme that does not conform to a second format; or the set of information bits indicates a mode not supported in connection with the second format. Or, a duplicate of at least one of the first field and the second field is included in the PHY preamble, to signal the first format.

Abstract: Systems and techniques relating to repeated signal detection are described. A described system includes a receiver to receive a frame including first and second portions, the first portion including first and second signal fields; a detector to determine a first decision metric component based on a hypothesis that the second signal field is a repeated version of the first signal field, determine a second decision metric component based on a hypothesis that the second signal field is not the repeated version, and make a determination, based on the first and second decision metric components, of whether the second signal field is the repeated version; and a decoder to process the second portion in accordance with a first format if the second signal field is not the repeated version, and to decode the second portion in accordance with a second format if the second signal field is the repeated version.

Abstract: Systems and methods are provided for encoding data based on an LDPC code using various inversion mechanisms to obtain parity bits. In some embodiments, an LDPC encoder may compute parity bits using a speculative recursion and correction mechanism. In these embodiments, the LDPC encoder may initiate a recursion using at least one speculative value in place of the actual value for a parity component. The speculative values may then be corrected using a correction factor. In other embodiments, an LDPC encoder is provided that can perform a blockwise inversion mechanism. This mechanism may be used on LDPC codes with parity check matrices having a parity portion composed partially of a large triangular matrix. In still other embodiments, a generic LDPC encoder is provided. The generic LDPC encoder can implement a variety of different encoding techniques, such as different inversion mechanisms, and may be processor-based or finite state machine-based.

Abstract: There is provided, in accordance with an embodiment, a method of decoding codewords in conjunction with a low-density parity-check (LDPC) code that defines variable nodes and check nodes, the method comprising receiving a codeword over a data channel; evaluating quality of the data channel; and iteratively updating values of the variable nodes to decode the codeword; wherein the values of the variable nodes are updated at different levels of numeric precision depending on the evaluated quality of the data channel.

Abstract: A quadrature clock divider circuit includes a divide-by-2 circuit having at least one undivided clock input, and generates at least one quadrature clock component and at least one inverted quadrature clock component, each having a 50% duty cycle. A resync circuit has as inputs the at least one undivided clock input, and the uninverted and inverted quadrature clock components. The resync circuit uses the uninverted and inverted quadrature clock components as selectors to generate, from the undivided clock input signals, at least one second quadrature clock component on a first signal path and at least one second inverted quadrature clock component on a second signal path. The first and second signal paths have a first portion in common, and each of the at least one second quadrature clock component and the at least one second inverted quadrature clock component has a second duty cycle percentage other than 50%.