Patent application number | Description | Published |
20090080543 | ADAPTIVE CYCLIC DELAY DIVERSITY FOR MOBILE DEVICES - Embodiments of the present invention provide for adaptive cyclic delay diversity to be used in wireless transmissions to mobile devices. The cyclic delay diversity may be adapted through cyclic delay parameters determined based at least in part on a determined speed of the mobile device. Other embodiments may be described and claimed. | 03-26-2009 |
20090086832 | PREAMBLE TECHNIQUES FOR COMMUNICATIONS NETWORKS - Techniques are disclosed involving preamble sequences. For instance, an apparatus includes a module to provide a preamble sequence having multiple values, where each of the values corresponds to an orthogonal frequency division multiplexing (OFDM) subcarrier. These multiple values may include multiple blocks of values based on a differentially encoded and scrambled row of a Hadamard matrix. The apparatus may further include a modulation module to produce an OFDM modulated signal from the preamble sequence. Further, techniques for the detection of such preambles are disclosed. | 04-02-2009 |
20100254433 | Techniques to format a symbol for transmission - A symbol structure is disclosed for use at least with wireless signal transmitters. The symbol structure includes a symbol that is spread over at least two symbol time periods. The symbol may include at least two replicas of the same code. The subcarrier spacing of subcarriers of the symbol has a p/q ratio of the subcarrier spacing of an IEEE 802.16e symbol. In some cases, the symbol includes interspersed null values. The decoding of the symbol involves performing a Fourier transform on the symbol. | 10-07-2010 |
20110216677 | TECHNIQUES FOR PROVIDING UPLINK FEEDBACK FOR DOWNLINK-ONLY RF CARRIERS IN A MULTICARRIER SYSTEM - Techniques are described for permitting uplink feedback for downlink transmission over downlink-only RF carriers to occur using uplink control channels belonging to another fully-configured RF carrier herein known as a primary carrier. Uplink feedback channels can be allocated for the downlink-only RF carriers in the uplink control regions of a fully-configured RF carrier immediately following the uplink control channels for the primary carrier are allocated. The uplink feedback channels for downlink-only RF carriers can be allocated based on global or local index number of each downlink-only RF carrier in sequential order based on ascending or descending sorting of the index numbers. | 09-08-2011 |
20130235714 | METHOD AND APPARATUS FOR A 1 MHZ LONG TRAINING FIELD DESIGN - An approach is provided for defining a 1 MHz preamble of a packet. The approach involves determining a preamble sequence of a packet, the preamble sequence having a determinable length. The approach also involves causing, at least in part, the preamble sequence to be divided into a predetermined number of blocks. The approach further involves causing, at least in part, a mathematical operation and a summation over the predetermined number of blocks and a corresponding number of received blocks. The approach also involves causing, at least in part, the summation to be maximized to determine the preamble sequence corresponds to one of a first bandwidth or a second bandwidth, the second bandwidth being greater than the first bandwidth, to determine a type of the packet. | 09-12-2013 |
20140105123 | TECHNIQUES TO MANAGE DWELL TIMES FOR PILOT ROTATION - Techniques to manage dwell times for pilot rotation are described. An apparatus may comprise a memory configured to store a data structure with a set of modulation and coding schemes (MCS) available to an orthogonal frequency division multiplexing (OFDM) system, each MCS having an associated pilot dwell time. The apparatus may further comprise a processor circuit coupled to the memory, the processor circuit configured to identify a MCS to communicate a packet using multiple subcarriers of the OFDM system, and retrieve a pilot dwell time associated with the MCS from the memory, the pilot dwell time to indicate when to shift a pilot tone between subcarriers of the multiple subcarriers during communication of the packet. Other embodiments are described and claimed. | 04-17-2014 |
20140126385 | Techniques to Update a Wireless Communication Channel Estimation - Examples are disclosed for updating a wireless communication channel estimation. In some examples, a packet may be transmitted or received via a communication channel, the packet having one or more pilot signals that may shift between subcarrier frequencies based on a predetermined first variable associated with a first time duration. A second variable associated with a second time duration may be determined by the receiver of the data packet. The second variable may enable a receiver of the data packet to decide how many pilot signals may be used to update an initial channel estimation for the communication channel. Other examples are described and claimed. | 05-08-2014 |
20140177514 | Techniques for Transmitting Data via Relay Communication Links - Examples are disclosed for transmitting data via a relay communication links. In some examples, a wireless device may receive a packet having a physical layer convergence protocol (PLCP) header that indicates whether the packet also includes a relay header placed before a media access controller header. The packet may be dropped or the relay header may be decoded based on a determination of whether the PLCP header indicates that the packet includes the relay header. Other examples are described and claimed. | 06-26-2014 |
20140185656 | TECHNIQUES TO ACCOMMODATE DIFFERENT CLASSES OF DEVICES IN A WIRELESS NETWORK - An apparatus, a method and a machine-readable storage medium to accommodate both high function and low cost wireless devices in a wireless network. An exemplary apparatus includes a receiver to wirelessly receive a first packet comprising first and second shifting pilot signals amidst first data symbols transmitted via multiple subcarriers in symbol sets; a transmitter to wireless transmit a second packet; and logic to track a phase shift using the first and second shifting pilot signals, to configure the receiver to compensate for the shift in phase, to refrain from using reception of the first and second shifting pilot signals to update an initial channel estimate derived from a preamble of the first packet, and to transmit third and fourth shifting pilot signals amidst second data symbols of the second packet. | 07-03-2014 |
20140269362 | Techniques to Update a Wireless Communication Channel Estimation - An apparatus, a method and one or more tangible computer-readable non-transitory storage media. The apparatus comprises a processor and a receive module configured to be executed by the processor to receive a data packet via a wireless communication channel, the packet including one or more pilot signals assigned to one or more corresponding subcarrier frequencies of the packet, the one or more pilot signals arranged to sweep through at least a portion of the plurality of subcarrier frequencies as a function of time. The apparatus further includes a channel estimator module configured to be executed by the processor to determine an initial channel estimation for the communication channel, and to further update a channel estimation for the communication channel using at least a portion of the pilot signals of the packet based on channel conditions. | 09-18-2014 |
20140321564 | TECHNIQUES TO MANAGE DWELL TIMES FOR PILOT ROTATION - Techniques to manage dwell times for pilot rotation are described. An apparatus may comprise a memory configured to store a data structure with a set of modulation and coding schemes (MCS) available to an orthogonal frequency division multiplexing (OFDM) system, each MCS having an associated pilot dwell time. The apparatus may further comprise a processor circuit coupled to the memory, the processor circuit configured to identify a MCS to communicate a packet using multiple subcarriers of the OFDM system, and retrieve a pilot dwell time associated with the MCS from the memory, the pilot dwell time to indicate when to shift a pilot tone between subcarriers of the multiple subcarriers during communication of the packet. Other embodiments are described and claimed. | 10-30-2014 |
Patent application number | Description | Published |
20130114523 | USER EQUIPMENT (UE)-SPECIFIC ASSIGNMENT OF DEMODULATION REFERENCE SIGNAL (DMRS) SEQUENCES TO SUPPORT UPLINK (UL) COORDINATED MULTIPOINT (CoMP) - Technology for user equipment (UE)-specific assigning of demodulation reference signal (DM-RS) sequences to support uplink (UL) coordinated multipoint (CoMP) is disclosed. One method can include a DM-RS sequence assignment device sorting the plurality of UE into a list according to a number of reception point (RP) links for each UE in a CoMP set, and assigning a base DM-RS sequence and a cyclic shift (CS) to a top-ranked UE from the list. The top-ranked UE can have a highest number of RP links. The DM-RS sequence assignment device can repeatedly assign a different CS of the base DM-RS sequence to a plurality of unassigned UE in a same cell as the top-ranked UE, and repeatedly assign the different CS of the base DM-RS sequence to a plurality of unassigned UE in a cooperatively served cell of the top-ranked UE. | 05-09-2013 |
20130157657 | FEMTOCELL DISCOVERY AND ASSOCIATION IN CELLULAR NETWORKS - Embodiments of a method and apparatus for discovery and association, by a mobile station, of a femto base station from a plurality of base stations. The mobile station may select a base station for consideration for association by decoding a physical layer identifier to determine that the base station is a macro base station and select a different base station based on other considerations. Other embodiments may be described and claimed. | 06-20-2013 |
20130195028 | SOUNDING REFERENCE SIGNAL ENHANCEMENT TO SUPPORT UPLINK COORDINATED MULTIPOINT - Systems and techniques for sounding reference signal enhancement to support uplink coordinated multipoint are described herein. A sounding reference signal may be assigned to a user equipment based on a relationship between the user equipment and a cell edge of a cell served by a wireless network device and serving the user equipment. | 08-01-2013 |
20130272198 | METHODS AND ARRANGEMENTS FOR ORTHOGONAL TRAINING SEQUENCES IN WIRELESS NETWORKS - Logic may implement an orthogonal frequency division multiplexing (OFDM) system operating in the one gigahertz and lower frequency bands. Logic may detect new long training sequences that are differentially orthogonal to each other for a first bandwidth mode of operation such as a one megahertz mode as well as differentially orthogonal to half of the long training sequence for a second bandwidth mode of operation such as a two megahertz or greater mode. Logic may implement two or more long training sequences for the first bandwidth mode of operation to transmit information based upon the selection of the particular long training sequence for the transmission. Logic may implement a new acknowledgement packet comprising a short training sequence and a long training sequence without a signal field and without a payload. And logic may implement bandwidth detection logic to classify a transmission based upon orthogonal properties of the long training sequences. | 10-17-2013 |
20130329815 | SYSTEMS AND METHODS FOR IMPLEMENTING IMPROVED FREQUENCY ESTIMATION - A system and method are provided for implementing improved frequency estimation for wireless communications in support of a broader set of use cases including outdoor use cases and use cases that involve lower power transmissions with reduced signal-to-noise ratios for receivers particularly in systems configured according to the pending IEEE 802.11 ah standard. These systems and methods provide greatly improved frequency estimation over that prescribed for devices operating according other IEEE 802.11 standards, including the frequency estimator conventionally used in systems operated according to the IEEE 802.11n standards, and the proposed frequency estimator specified for IEEE 802.11ac systems. The disclosed techniques facilitate improved frequency estimation schemes that reuse of a short training field (STF) stored in memory, employ joint STF-long training field (LTF) estimation, use portions of a guard interval (GI), and create of multiple-phase estimates, with different symbol separation to improve a signal-to-noise ratio of the frequency estimate. | 12-12-2013 |
20140010324 | METHODS AND ARRANGEMENTS FOR SELECTING CHANNEL UPDATES IN WIRELESS NETWORKS - Pilot logic may determine based upon channel and phase information how to process pilot tones that shift locations every N symbols in an orthogonal frequency division multiplexing (OFDM) packet transmission. Pilot logic may determine a signal-to-noise ratio (SNR) for the channel to determine how to process the shifting pilot tones. Pilot logic may also determine channel and phase information updates such as channel state information and phase correction information from pilot tones. In situations of high SNR, logic may use channel estimates and phase rotations that are obtained from locations of the pilot tones for phase tracking and updating the equalizer. In situations of low SNR, logic may use the phase rotations for phase tracking and not update the equalizer during the OFDM transmission. Logic may also determine the presence or absence of a Doppler effect on the transmission and transmit a selection for N to an access point in response. | 01-09-2014 |
20140025799 | CALENDAR-AWARE DEVICES - A client-server session is automatically initiated between a client-type device an a cloud-based server in a cloud-based computing environment based on user-defined parameters, thereby providing convenience and ease of use for a user for uploading, sharing and downloading media content to and from a content-sharing website. A user-preference database stores user-preference information, such as information relating to media-content-type information, media-content-source information, media-content-destination information, user-uploading-preference information, and/or uplink-network-preference and downlink-network-preference information. A rule is generated for uploading and/or downloading a designated media-content type to the content-sharing website based on the stored user preference information and at least one calendar event available from a calendar application. An event trigger signal is generated if the conditions of the rule are satisfied, and a communication controller then establishes a communication link to the content-sharing website and uploads and/or downloads the designated media content. | 01-23-2014 |
20140044112 | METHODS AND ARRANGEMENTS FOR BEAMFORMING REPORTS IN WIRELESS NETWORKS - Logic of an access point may transmit a null data packet for beamforming training and transmit a beamforming report poll to the first station on a user list before receiving a transmission from the first station on the user list. Logic may wait for a timeout period to determine whether the first station on the user list will respond to the null data packet prior to transmitting the beamforming report poll. Logic may receive from the first station an indication that the first station is a slow beamforming report responder. Logic may reorder the user list to position a fast beamforming responder as the first station. And logic of the station may determine that the station is unable to complete and transmit the report so the logic may wait to transmit the beamforming report in response to a subsequent beamforming report poll frame. | 02-13-2014 |
20140050254 | METHODS AND ARRANGEMENTS FOR CHANNEL UPDATES IN WIRELESS NETWORKS - Pilot logic may determine channel information updates such as channel state information and phase correction information from pilot tones that do not travel close to the DC tone or the band edge tones. Logic may skip channel updates and phase tracking from pilot tones that have traveled close to the DC tone or the edge tones. In other words, logic may process the shifting pilot tones except for the pilot tones located adjacent to the DC tone and the edge tones. Logic may use channel estimates and phase rotations that are obtained from previous locations of the pilot tones instead of pilot tones that are adjacent to the DC tone or the edge tones. Logic may access memory to store the channel information such as the phase correction information previously obtained and the channel state information previously obtained and derived from processing pilot tones at locations adjacent to the symbol indices next to the DC tone and the edge tones. | 02-20-2014 |
20140050255 | METHODS AND ARRANGEMENTS FOR CHANNEL UPDATES IN WIRELESS NETWORKS - Logic may calculate predicted phase rotations based upon more than one previously determined phase rotation. Logic may access memory to store and retrieve previously determined phase rotations to calculate predicted phase rotations. Logic may determine channel information updates such as channel state information and phase correction information from pilot tones that do not travel close to the direct current (DC) tone or the band edge (or guard) tones and replace the missing phase rotations with predicted phase rotations. Logic may skip phase tracking from pilot tones that have traveled close to the DC tone or the edge tones or that experience channel fading, which may result in a predicted phase rotation being more accurate than a phase rotation determined by processing the corresponding pilot tone. | 02-20-2014 |
20140050259 | METHODS AND ARRANGEMENTS FOR PHASE TRACKING IN WIRELESS NETWORKS - Logic may determine phase correction information from pilot tones. Logic may determine phase correction information from some of the pilot locations. Logic may process the shifting pilot tones for less than all of the pilot tones. Logic may process pilot tones at any location within orthogonal frequency division multiplexing (OFDM) packet. Logic may determine to process only pilot tones at the even or odd symbol indices or subcarriers. And logic may transmit a packet with a frame with a capabilities information field comprising an indication that a receiver may can process shifting pilot tones for phase tracking. | 02-20-2014 |
20140098724 | METHODS AND ARRANGEMENTS FOR FREQUENCY SELECTIVE TRANSMISSION - Logic may comprise hardware and/or code to select a narrow band from a wider channel bandwidth. Logic of communications between devices may select, e.g., a 1 or 2 MHz sub-channel from a wider channel bandwidth such as 4, 8, and 16 MHz and transmit packets on the selected 1 or 2 MHz channel. For instance, a first device may comprise an access point and a second device may comprise a station such as a low power sensor or a meter that may, e.g., operate on battery power. Logic of the devices may facilitate a frequency selective transmission scheme. Logic of the access point may transmit sounding packets or control frames across the sub-channels of the wide bandwidth channel, facilitating selection by the stations of a sub-channel and subsequent communications on the sub-channel between the access point and the station. | 04-10-2014 |
20140112246 | METHODS AND ARRANGEMENTS FOR FREQUENCY SELECTIVE TRANSMISSION - Logic such as hardware and/or code to narrow available sub-channels in frequency selective transmission communications in which a station selects a narrow band from a wider channel bandwidth. A frequency selective transmission scheme for communications devices may select a 1 or 2 MHz channel from a wider channel bandwidth (e.g., 4, 8, 16 MHz) that consists of a number of 1 or 2 MHz sub-channels and transmitting packets on the selected sub-channel. The access point may narrow the number of sub-channels available for selection by stations. Stations may narrow the number of sub-channels. Both the AP and the stations may operate to narrow the number of sub-channels. A medium access control sub-layer protocol common to the communications devices may facilitate a frequency selective transmission scheme. | 04-24-2014 |
20140119280 | METHODS AND ARRANGEMENTS TO MITIGATE COLLISIONS IN WIRELESS NETWORKS BY ENABLING COEXISTENCE OF DISPARATE BANDWIDTHS - Systems, devices, and methods for mitigating collisions between wireless transmissions operating at different bandwidths are disclosed. As such, a wireless device operating at a predefined bandwidth includes a transceiver that receives a signal across a wireless channel, a filter that generates a band-limited filtered signal at the predefined bandwidth of the wireless device, a correlating mechanism that correlates the band-limited filtered signal with a delayed, conjugated version of the band-limited filtered signal, logic that performs a moving average of the correlated filtered signals to determine correlation peaks, and logic configured to compare the correlation peaks with a predetermined threshold. With this configuration, if the correlation peaks are greater than the predetermined threshold, the received signal is determined to operate at a wider bandwidth than the predefined bandwidth of the wireless device, and the wireless device defers accessing the wireless channel to transmit until a predetermined time interval. | 05-01-2014 |
20140146722 | METHODS AND ARRANGEMENTS TO DECODE COMMUNICATIONS - Embodiments may comprise logic such as hardware and/or code to reduce power consumption by, e.g., a device such as a station or relay by implementing prediction logic to decode and determine whether a communication affects the operation of the device. Some embodiments may comprise logic to receive at least a portion of a header of a frame from a physical layer and begin to decode the portion of the header of the frame without first checking the correctness of the value in the frame check sequence field. In many embodiments, prediction logic may determine whether the frame could have an impact on the operation of the device. For circumstances in which the prediction logic determines that the frame will not have an impact, the MAC logic may terminate processing, receipt, and decoding of the frame and enter the device into a low power consumption state. | 05-29-2014 |
20140177427 | TRUNCATED ZADOFF-CHU SEQUENCE FOR LTE UPLINK REFERENCE SIGNALS - A method to generate truncated Zadoff-Chu sequences is disclosed. A large Zadoff-Chu sequence is generated, based on a maximum transmission bandwidth, then the sequence is truncated based on the actual transmission bandwidth. The Zadoff-Chu sequence is cyclicly extended, as needed, to maintain a quasi-orthogonal characteristic. The result is that there is an increased number of available Zadoff-Chu sequences for distribution in a wireless neighborhood and the rate of interference is reduced. | 06-26-2014 |
20140185502 | METHODS AND ARRANGEMENTS FOR A LOW POWER DEVICE IN WIRELESS NETWORKS - Some new low power architecture devices may, e.g., be associated with in a new device category in the IEEE 802.11ah Standard for devices with low power architecture. Some new low power architecture devices may only to support a subset of modulation and coding schemes (MCSs). Some new low power architecture devices negotiate the use of the subset of MCSs with an access point. Further new low power architecture devices address power consumption through modifications to the architecture of the new low power device. For instance, many new low power architecture devices remove, modify or bypass portions of the front-end transmitter circuitry and/or the front-end receiver circuitry such as a power amplifier, a low noise amplifier, predistortion circuitry, digital-to-analog and analog-to-digital converter resolutions, and stages of filtering. | 07-03-2014 |
20140185662 | METHODS AND ARRANGEMENTS FOR PHASE TRACKING FOR MULTI-MODE OPERATION IN WIRELESS NETWORKS - Logic may comprise a single phase tracking implementation for all bandwidths of operation and the logic may adaptively change pre-defined and stored track parameters if the receiving packet is 1 MHz bandwidth. Logic may detect a packet and long training fields before performing a 1 MHz classification. Logic may auto-detect 1 MHz bandwidth transmissions by a property of the long training field sequences. Logic may auto-detect 1 MHz bandwidth transmissions by detecting a Binary Phase Shift Keying (BPSK) modulated first signal field symbol rather than the Quadrature Binary Phase Shift Keying (QBPSK) associated with the 2 MHz or greater bandwidth transmissions. Logic may perform an algorithm to determine an estimated phase correction value for a given orthogonal frequency division multiplexing symbol and several embodiments integrate this value with an intercept multiplier that may be 0.2 for 1 MHz transmissions and, e.g., 0.5 for 2 MHz or greater bandwidth communication. | 07-03-2014 |
20140192820 | METHODS AND ARRANGEMENTS TO MITIGATE COLLISIONS IN WIRELESS NETWORKS - Logic for collision mitigation between transmissions of wireless transmitters and receivers operating at different bandwidths. Logic of the receivers may be capable of receiving and detecting signals transmitted at narrower bandwidths. In several embodiments, the receivers comprise a clear channel assessment logic that implements a guard interval (or cyclic prefix) detector to detect transmissions at narrower bandwidths. For instance, a two MegaHertz (MHz) bandwidth receiver may implement a guard interval detector to detect 1 MHz bandwidth signals and a 16M Hz bandwidth receiver may implement logic to detect one or more 1 MHz bandwidth signals and any other combination of, e.g., 1, 2, 4, 8 MHz bandwidth signals. In many embodiments, the guard interval detector may be implemented to detect guard intervals on a channel designated as a primary channel as well as on one or more non-primary channels. | 07-10-2014 |
20140233589 | METHOD AND APPARATUS FOR A 1 MHZ LONG TRAINING FIELD DESIGN - An approach is provided for defining a 1 MHz preamble of a packet. The approach involves determining a preamble sequence of a packet, the preamble sequence having a determinable length. The approach also involves causing, at least in part, the preamble sequence to be divided into a predetermined number of blocks. The approach further involves causing, at least in part, a mathematical operation and a summation over the predetermined number of blocks and a corresponding number of received blocks. The approach also involves causing, at least in part, the summation to be maximized to determine the preamble sequence corresponds to one of a first bandwidth or a second bandwidth, the second bandwidth being greater than the first bandwidth, to determine a type of the packet. | 08-21-2014 |
20150110051 | METHODS AND ARRANGEMENTS TO MITIGATE COLLISIONS IN WIRELESS NETWORKS - Logic for collision mitigation between transmissions of wireless transmitters and receivers operating at different bandwidths. Logic of the receivers may be capable of receiving and detecting signals transmitted at narrower bandwidths. In several embodiments, the receivers comprise a clear channel assessment logic that implements a guard interval (or cyclic prefix) detector to detect transmissions at narrower bandwidths. For instance, a two MegaHertz (MHz) bandwidth receiver may implement a guard interval detector to detect 1 MHz bandwidth signals and a 16 MHz bandwidth receiver may implement logic to detect one or more 1 MHz bandwidth signals and any other combination of, e.g., 1, 2, 4, 8 MHz bandwidth signals. In many embodiments, the guard interval detector may be implemented to detect guard intervals on a channel designated as a primary channel as well as on one or more non-primary channels. | 04-23-2015 |
20150124843 | SHORTENED TRAINING FIELD PREAMBLE STRUCTURE FOR HIGH EFFICIENCY WI-FI ENVIRONMENT - The disclosure generally relates to a shortened training field preamble structure for high-efficiency Wi-Fi environments. In one embodiment, the disclosure relates to a communication system having a transmitter transmitting a Master-Sync packet received by stationary and mobile receivers. The Master-Sync packet contains information for communicating in a HEW environment. Upon receipt each receiver decodes the Master-Sync packet to (i) estimate a frequency offset and/or an automatic gain control (AGC) setting; (ii) select a transmission frequency consistent with the frequency offset; and/or (iii) determine a new transmission power consistent with the AGC; (iv) tune to a new frequency offset and gain control setting to receive subsequent packets from the transmitter. | 05-07-2015 |
20150139089 | MASTER STATION AND METHOD FOR HIGH-EFFICIENCY WI-FI (HEW) COMMUNICATION USING TRAVELING PILOTS - Embodiments of a master station and method for high-efficiency Wi-Fi (HEW) communication using traveling pilots are generally described herein. In some embodiments, the master station is arranged for communicating with a plurality of HEW and may be configured to transmit, during an initial portion of an HEW control period, a master-sync transmission that includes a multi-device HEW preamble arranged to signal and identify data fields for a plurality of scheduled HEW stations. The master station may transmit during the HEW control period the data fields with traveling pilots to the scheduled HEW stations. The master station may also receive data fields with traveling pilots transmitted by the scheduled HEW stations during the HEW control period. The traveling pilots may comprise pilot signals that are shifted among orthogonal-frequency multiplexed (OFDM) subcarriers during transmission of one or more of the data fields. | 05-21-2015 |
20150139091 | HEW MASTER STATION AND METHOD FOR COMMUNICATING IN ACCORDANCE WITH A SCHEDULED OFDMA TECHNIQUE ON SECONDARY CHANNELS - Embodiments of a high-efficiency WLAN (HEW) master station and method for communicating in accordance with a scheduled OFDMA technique on secondary channels are generally described herein. An access point is configured to operate as part of a basic-service set (BSS) that includes a plurality of high-efficiency WLAN (HEW) stations and a plurality of legacy stations. The BSS operates on a primary channel and one or more secondary channels. In accordance with some embodiments, the access point may communicate with one or more of the HEW stations on one or more of the secondary channels in accordance with a scheduled OFDMA communication technique when the primary channel is utilized for communication with one or more of the legacy devices. | 05-21-2015 |
20150139118 | MASTER STATION AND METHOD FOR HIGH-EFFICIENCY WI-FI (HEW) COMMUNICATION WITH A MINIMUM OFDMA BANDWIDTH UNIT - Embodiments of a master station and method for communicating in a Wi-Fi network in accordance with a high-efficiency Wi-Fi (HEW) technique are generally described herein. In some embodiments, the master station is configured to communicate with scheduled stations using the antennas within a bandwidth comprising one or more 20 MHz Wi-Fi channels using a plurality of minimum orthogonal frequency division multiple access (OFDMA) bandwidth units during an OFDMA control period during which the master station has exclusive control of a wireless medium. Each minimum OFDMA bandwidth unit may comprise a predetermined number of subcarriers that do not include guard subcarriers of the channel wherein the guard subcarriers are provided at band edges of the bandwidth, the guard subcarriers being in addition to the subcarriers of each of the minimum OFDMA bandwidth units. In some embodiments, no guard subcarriers are provided between the minimum OFDMA bandwidth units within a 20 MHz channel. | 05-21-2015 |
20150139119 | MASTER STATION AND METHOD FOR HEW COMMUNICATION USING A TRANSMISSION SIGNALING STRUCTURE FOR A HEW SIGNAL FIELD - Embodiments of a transmission signaling structure for HEW are defined to carry packet information to configure OFDMA receivers for demodulation of a specific portion of the packet and/or to configure receivers for transmission using specific OFDMA and MU-MIMO resources. In some embodiments, the specific portion of the packet comprises one or more minimum bandwidth units of one or more 20 MHz channels. Each 20 MHz bandwidth structure may comprise several minimum bandwidth units to allow each 20 MHz channel to have a have smaller granularity than 20 MHz. | 05-21-2015 |
20150139205 | ACCESS POINT AND METHODS FOR DISTINGUISHING HEW PHYSICAL LAYER PACKETS WITH BACKWARDS COMPATIBILITY - Embodiments of a system and methods for distinguishing high-efficiency Wi-Fi (HEW) packets from legacy packets are generally described herein. In some embodiments, an access point may select a value for the length field of a legacy signal field (L-SIG) that is non-divisible by three for communicating with HEW stations and may select a value for the length field that is divisible by three for communicating with legacy stations. In some embodiments, the access point may select a phase rotation for application to the BPSK modulation of at least one of the first and second symbols of a subsequent signal field to distinguish a high-throughput (HT) PPDU, a very-high throughput (VHT) PPDU and an HEW PPDU. | 05-21-2015 |
20150139206 | HIGH-EFFICIENCY WLAN (HEW) MASTER STATION AND METHODS TO INCREASE INFORMATION BITS FOR HEW COMMUNICATION - Embodiments of an access point and method for high-efficiency WLAN (HEW) communication are generally described herein. In some embodiments, the access point may be configured to operate as a master station and may configure an HEW frame to include a legacy signal field (L-SIG), an HEW signal field (HEW SIG-A) following the L-SIG, and one or more HEW fields following the HEW SIG-A. The L-SIG may be configured for transmission using a legacy number of data subcarriers, a legacy number of pilot subcarriers and a number of additional reference subcarriers modulated with a known reference sequence. At least one symbol of the HEW SIG-A and the one or more HEW fields following the HEW SIG-A of the HEW frame may be configured for transmission using additional data subcarriers. The additional data subcarriers may correspond to the additional reference subcarriers of the L-SIG. | 05-21-2015 |
20150195849 | SYSTEMS, METHODS AND DEVICES FOR MULTIPLE SIGNAL CO-EXISTENCE IN MULTIPLE-USE FREQUENCY SPECTRUM - Co-existence muting gaps can be included in an LTE protocol over unlicensed spectrum to enable a more efficient sharing with other wireless technologies, including wireless local area networks (WLANs). For example, an LTE protocol can be altered to include muting gaps that align with a WLAN beacon. In another example, a WLAN access point (AP) can create an information element (IE) that describes muting gaps available to WLAN stations (STAs) such that STAs can remain in a low power state until a muting gap is available. In yet another example, a cell tower and WLAN can be configured such that WLAN beacons occur when the cell tower is not transmitting during selected portions of LTE frames. | 07-09-2015 |
20150223075 | SYSTEMS, METHODS AND DEVICES FOR CHANNEL RESERVATION - A device uses a first protocol to incorporate a reservation of a medium using a second protocol within the bounds of the first protocol. For example, an evolved node B (also known as an e node B or eNB) using a long term evolution over unlicensed spectrum (LTE-U) protocol can be configured to reserve unlicensed spectrum using a (wireless local area network) WLAN message placed within a muting gap within the LAA protocol. In one embodiment, the eNB selects to broadcast the WLAN reservation message using a set of options including: (1) from a control channel region of LAA, (2) from a muting gap indicated by a reservation muting symbol pattern indicator, (3) from a time division duplex (TDD) guard period (GP), (4) from a TDD uplink pilot time slot (UpPTS), (5) from an empty uplink (UL) subframe or (6) from a sounding reference signal (SRS). | 08-06-2015 |
Patent application number | Description | Published |
20110130981 | SYSTEM AND METHODS FOR AGING COMPENSATION IN AMOLED DISPLAYS - Methods and systems to provide baseline measurements for aging compensation for a display device are disclosed. An example display system has a plurality of active pixels and a reference pixel. Common input signals are provided to the reference pixel and the plurality of active pixels. The outputs of the reference pixel is measured and compared to the output of the active pixels to determine aging effects. The display system may also be tested applying a first known reference current to a current comparator with a second variable reference current and the output of a device under test such as one of the pixels. The variable reference current is adjusted until the second current and the output of the device under test is equivalent of the first current. The resulting current of the device under test is stored in a look up table for a baseline for aging measurements during the display system operation. The display system may also be tested to determine production flaws by determining anomalies such as short circuits in pixel components such as OLEDs and drive transistors. | 06-02-2011 |
20120293478 | SYSTEM AND METHODS FOR EXTRACTION OF THRESHOLD AND MOBILITY PARAMETERS IN AMOLED DISPLAYS - Disclosed is a system and method to improve the extraction of transistor and OLED parameters in an AMOLED display for compensation of programming voltages to improve image quality. A pixel circuit includes an organic light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input to provide the programming signal, and a storage device to store the programming signal. A charge-pump amplifier has a current input and a voltage output. The charge-pump amplifier includes an operational amplifier in negative feedback configuration. The feedback is provided by a capacitor connected between the output and the inverting input of the operational amplifier. A common-mode voltage source drives the non-inverting input of the operational amplifier. An electronic switch is coupled across the capacitor to reset the capacitor. A switch module including the input is coupled to the output of the pixel circuit and an output is coupled to the input of the charge-pump amplifier. The switch module includes a set of electronic switches that may be controlled by external control signals to steer current in and out of the pixel circuit and provide a discharge path between the pixel circuit and the charge-pump amplifier and isolating the charge-pump amplifier from the pixel circuit. A controller is coupled to the pixel circuit, charge-pump amplifier and the switch module. The controller controls input signals to the pixel circuit, charge-pump amplifier and switch module in a predetermined sequence to produce an output voltage value which is a function of a parameter of the pixel circuit. The sequence includes providing a program voltage to the programming input to either pre-charge an internal capacitance of the pixel circuit to a charge level and transfer the charge to the charge-pump amplifier via the switch module to generate the output voltage value or provide a current from the pixel circuit to the charge-pump amplifier via the switch module to produce the output voltage value by integration over a certain period of time. | 11-22-2012 |
20130099692 | SYSTEM AND METHOD FOR FAST COMPENSATION PROGRAMMING OF PIXELS IN A DISPLAY - Circuits for programming a circuit with decreased programming time are provided. Such circuits include a storage device such as a capacitor for storing display information and for ensuring a driving device such as a driving transistor drives a light emitting device according to the display information. To increase programming time, the pixel circuits may be pre-charged or a biasing current may be applied to charge and/or discharge a data line and/or the driving device. Aspects of the present disclosure allow for the biasing current to drain partially through the storage device to allow the portion of the biasing current applied to the driving device to remain small while the data line discharges. Furthermore, the present disclosure provides display architectures and operation schemes for display arranged in segments each including a plurality of pixel circuits. | 04-25-2013 |
20130100173 | SYSTEMS AND METHODS FOR OPERATING PIXELS IN A DISPLAY TO MITIGATE IMAGE FLICKER - Circuits for programming a circuit with decreased programming time are provided. Such circuits include a storage device such as a capacitor for storing display information and for ensuring a driving device such as a driving transistor drives a light emitting device according to the display information. The present disclosure provides driving schemes for decreasing flickering perceived while displaying video content by introducing idle phases in between in emission phases to increase the effective refresh rate of a display. Driving schemes are also disclosed for reducing the effects of cross-talk by ensuring that programming information is refreshed in a display array that utilizes a driver connected to multiple data lines via a multiplexer. | 04-25-2013 |
20130201173 | SYSTEM AND METHODS FOR EXTRACTION OF THRESHOLD AND MOBILITY PARAMETERS IN AMOLED DISPLAYS - A system to improve the extraction of transistor and OLED parameters in an AMOLED display includes a pixel circuit having an organic light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input to provide the programming signal, and a storage device to store the programming signal. A charge-pump amplifier has a current input and a voltage output. The charge-pump amplifier includes an operational amplifier in negative feedback configuration. The feedback is provided by a capacitor connected between the output and the inverting input of the operational amplifier. A common-mode voltage source drives the non-inverting input of the operational amplifier. An electronic switch is coupled across the capacitor to reset the capacitor. A switch module including the input is coupled to the output of the pixel circuit and an output is coupled to the input of the charge-pump amplifier. | 08-08-2013 |
20130235023 | SYSTEM AND METHODS FOR AGING COMPENSATION IN AMOLED DISPLAYS - A voltage-programmed display system allows measurement of effects on pixels in a panel that includes both active pixels and reference pixels coupled to a supply line and a programming line. The reference pixels are controlled so that they are not subject to substantial changes due to aging and operating conditions over time. A readout circuit is coupled to the active pixels and the reference pixels for reading at least one of current, voltage or charge from the pixels when they are supplied with known input signals. The readout circuit is subject to changes due to aging and operating conditions over time, but the readout values from the reference pixels are used to adjust the readout values from the active pixels to compensate for the unwanted effects. | 09-12-2013 |
20130257845 | RESETTING CYCLE FOR AGING COMPENSATION IN AMOLED DISPLAYS - A method of voltage-programming a pixel circuit in a display panel to remove, before programming the pixel circuit, effects due to short-term effects such as caused by fast light transitions or effects due to previous pixel circuit measurements such as charge trapping. During a resetting cycle, the pixel circuit is programmed with a reset voltage value corresponding to a maximum or a minimum voltage value. Then, during a calibration cycle, the pixel circuit is programmed with a calibration voltage based on previously extracted data for the pixel circuit, a pixel current of the pixel circuit is measured, and the extracted data for the pixel circuit is updated based on the measured pixel current. Then, the pixel circuit is programmed with a video data that is calibrated with the updated extracted data. The pixel circuit is finally driven according to the programmed video data and emits a commensurate amount of light. | 10-03-2013 |
20130307834 | SYSTEM AND METHODS FOR EXTRACTION OF THRESHOLD AND MOBILITY PARAMETERS IN AMOLED DISPLAYS - Disclosed is a system and method to improve the extraction of transistor and OLED parameters in an AMOLED display for compensation of programming voltages to improve image quality. A pixel circuit includes an organic light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input to provide the programming signal, and a storage device to store the programming signal. A charge-pump amplifier has a current input and a voltage output. The charge-pump amplifier includes an operational amplifier in negative feedback configuration. The feedback is provided by a capacitor connected between the output and the inverting input of the operational amplifier. A common-mode voltage source drives the non-inverting input of the operational amplifier. An electronic switch is coupled across the capacitor to reset the capacitor. A switch module including the input is coupled to the output of the pixel circuit and an output is coupled to the input of the charge-pump amplifier. The switch module includes a set of electronic switches that may be controlled by external control signals to steer current in and out of the pixel circuit and provide a discharge path between the pixel circuit and the charge-pump amplifier and isolating the charge-pump amplifier from the pixel circuit. A controller is coupled to the pixel circuit, charge-pump amplifier and the switch module. The controller controls input signals to the pixel circuit, charge-pump amplifier and switch module in a predetermined sequence to produce an output voltage value which is a function of a parameter of the pixel circuit. The sequence includes providing a program voltage to the programming input to either pre-charge an internal capacitance of the pixel circuit to a charge level and transfer the charge to the charge-pump amplifier via the switch module to generate the output voltage value or provide a current from the pixel circuit to the charge-pump amplifier via the switch module to produce the output voltage value by integration over a certain period of time. | 11-21-2013 |
20130314394 | DISPLAY SYSTEMS WITH COMPENSATION FOR LINE PROPAGATION DELAY - A method for characterizing and eliminating the effect of propagation delay on data and monitor lines of AMOLED panels is introduced. A similar technique may be utilized to cancel the effect of incomplete settling of select lines that control the write and read switches of pixels on a row. | 11-28-2013 |
20140062993 | SYSTEM AND METHODS FOR EXTRACTION OF PARASITIC PARAMETERS IN AMOLED DISPLAYS - A system reads a desired circuit parameter from a pixel circuit that includes a light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input, and a storage device to store a programming signal. One embodiment of the extraction system extracts a parasitic capacitance value from a pixel circuit by measuring at least one parameter of the pixel circuit when in a first state having a first set of operating voltages and currents, measuring at least one parameter of the pixel circuit when in a second state having a second set of operating voltages and currents different from the first set, and extracting the value of a selected parasitic capacitance from the measurements. | 03-06-2014 |
20140084932 | SYSTEM AND METHODS FOR EXTRACTION OF THRESHOLD AND MOBILITY PARAMETERS IN AMOLED DISPLAYS - A system reads a desired circuit parameter from a pixel circuit that includes a light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input, and a storage device to store a programming signal. One embodiment of the extraction system turns off the drive device and supplies a predetermined voltage from an external source to the light emitting device, discharges the light emitting device until the light emitting device turns off, and then reads the voltage on the light emitting device while that device is turned off. The voltages on the light emitting devices in a plurality of pixel circuits may be read via the same external line, at different times. | 03-27-2014 |
20140198092 | DRIVING SCHEME FOR EMISSIVE DISPLAYS PROVIDING COMPENSATION FOR DRIVING TRANSISTOR VARIATIONS - Systems and methods detect and compensate for process or performance-related non-uniformities and/or degradation in displays. The systems and methods can compare a device current with one or more reference currents to generate an output signal indicative of the difference between the device and reference currents. This output voltage can be amplified, and quantized and then be used to determine how the device current differs from the reference current and to adjust the programming voltage for the device of interest accordingly. | 07-17-2014 |
20140252988 | PIXEL CIRCUITS FOR AMOLED DISPLAYS - The OLED voltage of a selected pixel is extracted from the pixel produced when the pixel is programmed so that the pixel current is a function of the OLED voltage. One method for extracting the OLED voltage is to first program the pixel in a way that the current is not a function of OLED voltage, and then in a way that the current is a function of OLED voltage. During the latter stage, the programming voltage is changed so that the pixel current is the same as the pixel current when the pixel was programmed in a way that the current was not a function of OLED voltage. The difference in the two programming voltages is then used to extract the OLED voltage. | 09-11-2014 |
20140285407 | SYSTEM AND METHODS FOR EXTRACTION OF THRESHOLD AND MOBILITY PARAMETERS IN AMOLED DISPLAYS - A system extracts effective parameters from a pixel circuit that includes a light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input, and a storage device to store a programming signal. The system measures the value of at least one operating parameter of the pixel circuit at a plurality of levels, and then extracts the value of at least one related parameter of the pixel circuit, based on the measured values of the at least one operating parameter. The measured values of the operating parameter are translated to effective values for driving the pixel circuit, based on the extracted value. Then effective parameters for driving effective devices in the pixel circuit are extracted, based on the translated values, and stored for use in compensating input signals to the pixel circuit. | 09-25-2014 |
20140368491 | PIXEL CIRCUITS FOR AMOLED DISPLAYS - A method and system determine the characteristics of drive devices and load devices in selected pixels in an array of pixels in a display in which each pixel includes a drive device for supplying current to a load device. The method and system supply current to the load device via the drive device in a selected pixel, the current being a function of a current effective characteristic of at least one of the drive device and the load device; measure the current via a measurement line that is shared by adjacent pixels, and extract the value of a selected effective characteristic of one of the drive and load devices from the effect of the current on another of the drive and load devices. Current may be measured via a read transistor in each pixel. | 12-18-2014 |
20140375701 | SYSTEM AND METHODS FOR AGING COMPENSATION IN AMOLED DISPLAYS - Methods and systems to provide baseline measurements for aging compensation for a display device are disclosed. An example display system has a plurality of active pixels and a reference pixel. Common input signals are provided to the reference pixel and the plurality of active pixels. The outputs of the reference pixel is measured and compared to the output of the active pixels to determine aging effects. The display system may also be tested applying a first known reference current to a current comparator with a second variable reference current and the output of a device under test such as one of the pixels. The variable reference current is adjusted until the second current and the output of the device under test is equivalent of the first current. The resulting current of the device under test is stored in a look up table for a baseline for aging measurements during the display system operation. The display system may also be tested to determine production flaws by determining anomalies such as short circuits in pixel components such as OLEDs and drive transistors. | 12-25-2014 |
20150054811 | PIXEL CIRCUITS FOR AMOLED DISPLAYS - A system for driving a display that includes a plurality of pixel circuits arranged in an array, each of the pixel circuits including a light emitting device and a driving transistor for conveying a driving current through the light emitting device. Each of a first plurality of supply lines is associated with at least one pixel circuit in a preselected segment of the array, the first plurality of supply lines providing driving currents to the at least one pixel circuit in the preselected segment. Each of a plurality of voltage supplies is configured to provide a supply voltage to the at least one pixel circuit in the preselected segment of the array, the voltage supplies being controllably coupled to the pixel circuits in the preselected segment of the array. A controller determines which of the plurality of voltage supplies to connect to the preselected segment of the array. | 02-26-2015 |
20150077315 | DISPLAY SYSTEMS WITH COMPENSATION FOR LINE PROPAGATION DELAY - A method for characterizing and eliminating the effect of propagation delay on data and monitor lines of AMOLED panels is introduced. A similar technique may be utilized to cancel the effect of incomplete settling of select lines that control the write and read switches of pixels on a row. | 03-19-2015 |
20150213744 | SYSTEM AND METHODS FOR EXTRACTION OF THRESHOLD AND MOBILITY PARAMETERS IN AMOLED DISPLAYS - A system to improve the extraction of transistor and OLED parameters in an AMOLED display includes a pixel circuit having an organic light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input to provide the programming signal, and a storage device to store the programming signal. A charge-pump amplifier has a current input and a voltage output. The charge-pump amplifier includes an operational amplifier in negative feedback configuration. The feedback is provided by a capacitor connected between the output and the inverting input of the operational amplifier. A common-mode voltage source drives the non-inverting input of the operational amplifier. An electronic switch is coupled across the capacitor to reset the capacitor. A switch module including the input is coupled to the output of the pixel circuit and an output is coupled to the input of the charge-pump amplifier. | 07-30-2015 |