| ATHEROS COMMUNICATIONS, INC. Patent applications |
| Patent application number | Title | Published |
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| 20120105280 | SYNCHRONIZED MEASUREMENT SAMPLING IN A NAVIGATION DEVICE - In a hot start mode of a navigation device, the process of obtaining pseudo-range measurements can be synchronized with the processes of tracking navigation satellites and initializing a positioning unit to compute a position, velocity, and time (PVT) solution of the navigation device. This can influence a time instant at which the pseudo-range measurements are determined and a time to first fix, depending on whether the navigation device is in a strong or weak signal environment. A measurement unit can receive a first indication that a predetermined number of navigation satellites have been acquired and that navigation signals transmitted by the acquired navigation satellites have been locked. The measurement unit can receive a second indication that the positioning unit has been initialized to compute the PVT solution. In response to receiving both indications, the measurement unit can obtain the pseudo-range measurements. Accordingly, the positioning unit can compute the PVT solution. | 05-03-2012 |
| 20120093240 | INTERFERENCE DETECTION IN A POWERLINE COMMUNICATION NETWORK - A powerline communication (PLC) network can be subject to noise/interference resulting in loss of throughput and data corruption for PLC devices connected to the PLC network. A powerline interference analyzer can be implemented in the PLC network for detecting sources of the noise. The powerline interference analyzer can determine powerline network noise characteristics that are representative of noise on the PLC network and can analyze the powerline network noise characteristics to determine one or more noise patterns. The noise patterns can be compared with a plurality of predefined noise signatures that are representative of corresponding each of a plurality of noise sources. Consequently, at least one noise source that is associated with the noise patterns can be identified from the plurality of the noise sources. | 04-19-2012 |
| 20120093151 | COEXISTENCE MECHANISM FOR NON-COMPATIBLE POWERLINE COMMUNICATION DEVICES - A powerline network may comprise powerline communication (PLC) devices of a first class of PLC devices that are incompatible with PLC devices of a second class of PLC devices. This can result in interference between communications of the first and the second classes of PLC devices. A dual mode PLC device that is compatible with the first and the second classes of PLC devices can be implemented for coexistence with both classes of PLC devices. The dual mode PLC device can determine whether the powerline network comprises a combination of PLC devices of the first and the second classes of PLC devices. One of a plurality of packet headers that is compatible with both the classes of PLC devices can be selected for transmission in response to determining that the powerline network comprises a combination of PLC devices of the first and the second classes of PLC devices. | 04-19-2012 |
| 20120072110 | INDOOR POSITIONING USING PRESSURE SENSORS - A pressure sensor can be implemented on a network device to minimize vertical positioning errors of the network device in an indoor environment. A reference altitude and a reference pressure associated with an access point in the indoor environment are received at the network device via a communication network. A pressure is determined at the network device in the indoor environment. An altitude of the network device associated with the pressure at the network device in the indoor environment is calculated based, at least in part, on the pressure at the network device, the reference pressure, and the reference altitude. A position of the network device in the indoor environment is determined based, at least in part, on the altitude of the navigation device and location information received from at least the access point. | 03-22-2012 |
| 20120063335 | PACKET IDENTIFICATION FOR POWER SAVING IN WIRELESS COMMUNICATION NETWORKS - A network coordinator can assign an association identifier (AID) and/or a group identifier (GID) to identify a client station to which a packet is to be transmitted and to enable the client station to determine whether to receive an incoming packet. The network coordinator can randomly generate a base AID that is representative of the network coordinator and can assign at least one AID to client stations to minimize the probability of client stations associated with proximate network coordinators being assigned the same AIDs. The network coordinator can also randomly assign at least one GID to a group of client stations to minimize the probability of groups of client stations associated with the proximate network coordinators being assigned the same GID. The client station can analyze indications of a received AID and/or received GID to determine whether to receive the packet or whether to switch to an inactive power state. | 03-15-2012 |
| 20120062421 | PHASE ROTATION TECHNIQUES IN A MULTI-USER WIRELESS COMMUNICATION ENVIRONMENT - A mechanism for mitigating inter-user interference in a multi-user wireless communication environment is disclosed. A first network device determines a plurality of steering matrices, associated with a corresponding plurality of subcarriers, for each of multiple destination devices associated with the first network device. A phase difference between corresponding steering vectors of each pair of consecutive steering matrices of the plurality of steering matrices associated with each of the destination devices is determined and phase rotation is performed to maintain phase continuity between the consecutive steering matrices. One or more pre-coding matrices are calculated based on at least a subset of the plurality of steering matrices associated with the multiple destination devices. The one or more pre-coding matrices are applied to data to be transmitted to the multiple destination devices to mitigate interference between each of the multiple destination devices. | 03-15-2012 |
| 20120059578 | POSITIONING NETWORK AVAILABILITY AND RELIABILITY BASED ROUTING - A routing system can be configured to determine a route based on availability and reliability of location reference devices to determine a most reliable route between a source and a destination. Visibility information that is indicative of availability of at least a threshold number of location reference devices along the route can be determined. For each of a plurality of routes between the source and the destination, a reliability rating associated with the route can be determined based on the visibility information associated with the route. The reliability rating is indicative of a reliability of the route and an ability of the routing system to maintain continuous connectivity to the at least the threshold number of location reference devices along the route. The reliability ratings of the plurality of routes are compared to identify and to present one of the plurality of routes with a highest reliability rating. | 03-08-2012 |
| 20120033682 | BALANCED BIT LOADING FOR COMMUNICATION NETWORKS SUBJECT TO BURST INTERFERENCE - Wired and wireless communication networks can be subject to burst interference resulting in loss of throughput and data corruption. In a communication system comprising a transmitting network device and a receiving network device, the transmitting network device can be configured to implement balanced bit loading for retransmitting packets of a failed packet transmission. On receiving a request for retransmission from the receiving network device, the transmitting network device can identify and eliminate sub-carriers that are associated with a bit load that is less than a predefined bit load threshold. The transmitting network device can attempt to reallocate bit loads of the eliminated sub-carriers to remaining sub-carriers across two or more constituent symbols per original symbol. | 02-09-2012 |
| 20120033619 | DYNAMIC BIT ALLOCATION FOR COMMUNICATION NETWORKS SUBJECT TO BURST INTERFERENCE - Wired and wireless communication networks can be subject to burst interference resulting in loss of throughput and data corruption. In a communication system comprising a transmitting network device and a receiving network device, the transmitting network device can be configured to implement a dynamic bit allocation technique for retransmitting packets of a failed packet transmission. On receiving a request for retransmission from the receiving network device, the transmitting network device can dynamically allocate bits of original symbols across two or more constituent symbols per original symbol. The transmitting network device can allocate the two or more constituent symbols across one or more retransmission packets to exploit time diversity. The transmitting network device can also vary modulation and coding schemes and other transmit parameters to generate robust retransmission packets. | 02-09-2012 |
| 20120014415 | TRANSMITTER BEAMFORMING STEERING MATRIX PROCESSING AND STORAGE - A mechanism for processing beamforming steering matrices in a transceiver system. A plurality of beamforming steering matrices associated with a plurality of subcarriers of an RF signal received at the transceiver system are generated. The beamforming steering matrices are compressed and stored. The beamforming steering matrices may also be grouped or sub-sampled prior to being stored. The beamforming steering matrices are decompressed and ungrouped before being applied to data to be transmitted. Prior to ungrouping the beamforming steering matrices, a phase difference between corresponding beamforming steering vectors of consecutive beamforming steering matrices is determined. Phase rotation is performed on the corresponding beamforming steering vectors based on the determined phase difference associated with the corresponding beamforming steering vectors to improve phase continuity between consecutive beamforming steering matrices. | 01-19-2012 |
| 20110268051 | SYSTEM AND METHOD FOR CONTROLLING WLAN AND BLUETOOTH COMMUNICATIONS - This disclosure involves methods and systems for controlling WLAN and Bluetooth communications by allocating bandwidth into times blocs having a first segment with Bluetooth priority and a second segment with WLAN priority. Access to the wireless communication medium is signaled over an interface connecting the WLAN and Bluetooth modules. Downlink traffic is modulated by signaling the WLAN access point to buffer traffic during the first segment. WLAN traffic can also be modulated by allowing reception and blocking transmission WLAN signals during the first segment. Further, while high priority Bluetooth transmission are preferably always allowed, low priority Bluetooth transmission can be restricted during the second period, depending upon the respective states of the WLAN and Bluetooth modules. A coexistence agent can be used to transfer relevant information between the WLAN and Bluetooth modules. | 11-03-2011 |
| 20110268024 | DETECTION OF CO-LOCATED INTERFERENCE IN A MULTI-RADIO COEXISTENCE ENVIRONMENT - Unscheduled transmissions of one wireless network device while a collocated wireless network device has control of a communication medium can corrupt packets received by the collocated wireless network device. Interference between the collocated wireless network devices can lead to degradation in performance of either/both the wireless network devices. In a communication system comprising a first wireless network device collocated with a second wireless network device, the first wireless network device can be configured to transmit a coexistence message to the second wireless network device when the first wireless network device transmits a packet without control of the communication medium. On receiving the coexistence message indicating that the first wireless network device transmitted a packet without control of the communication medium, the second wireless network device can discard any packets received at the second wireless network device and can request retransmission of the discarded packets. | 11-03-2011 |
| 20110057837 | SINGLE LOCAL OSCILLATOR FREQUENCY BAND TO RECEIVE DUAL-BAND SIGNALS - A dual-band GPS receiver and method and apparatus for downconversion of dual-band GPS signals. A dual-band GPS receiver in accordance with the present invention comprises an antenna, a Radio Frequency (RF) section, coupled to the antenna, and a baseband section, coupled to the RF section, wherein the RF section comprises a receiver, the receiver receiving signals from a first GPS frequency band and a second GPS frequency band, a local oscillator having a local oscillator frequency, and a mixer, coupled to the receiver and the local oscillator, for selectively mixing the local oscillator frequency with the first GPS frequency band and a second GPS frequency band, wherein the local oscillator frequency downconverts the first GPS frequency band and the second GPS frequency band into a common downconversion frequency band. | 03-10-2011 |
| 20100284316 | DYNAMIC ENERGY SAVING MECHANISM FOR ACCESS POINTS - Mobile access points typically run on batteries, and therefore, can operate for a limited amount of time without an external power source. However, because the access point service model requiring the access point to always be available and the access point's limited battery capacity reduces the time that the mobile access point can be used. Functionality can be incorporated in mobile access points to implement power saving mechanisms by altering the service model that requires the access point to always be available. Configuring the access point to enter into a low powered state for a predefined period of time can conserve mobile access point power and prolong battery life. Functionality for implementing power saving mechanisms can also be incorporated on fixed access points for efficient utilization of computing resources. | 11-11-2010 |
| 20100111212 | Decision Feedback Channel Estimation And Pilot Tracking for OFDM Systems - Current OFDM systems use a limited number of symbols and/or sub-channels to provide approximations for channel estimations and pilot tracking, i.e. phase estimations. For example, two training symbols in the preamble of a data packet are used to provide channel estimation. Four of the fifty-four sub-channels are reserved for providing phase estimation. However, noise and other imperfections can cause errors in both of these estimations, thereby degrading system performance. Advantageously, decision feedback mechanisms can be provided to significantly improve channel estimation and pilot tracking in OFDM systems. The decision feedback mechanisms can use data symbols in the data packet to improve channel estimation as well as data sub-channels to improve pilot tracking. | 05-06-2010 |
| 20090323524 | INVOKING DIFFERENT WIRELESS LINK RATE SELECTION OPERATIONS FOR DIFFERENT TRAFFIC CLASSES - Functionality can be implemented within a device or chip to select different sets of wireless link rate determination operations that account for different degrees of presentation time sensitivity that correspond to different classes of traffic. The device or chip can infer or explicitly determine presentation time sensitivity based, at least in part, on traffic class. The selected wireless link rate operations select link rates for the different classes of traffic. A first set of the wireless link rate determination operations can choose a smoother and more stable wireless link rate for the wireless traffic class that conveys presentation time sensitive content. A second of the wireless link rate determination operations can choose a fastest possible wireless link rate, which may be more susceptible to jitter and delay, for a traffic class that is less sensitive. | 12-31-2009 |
| 20090311979 | POLAR MODULATOR WITH PATH DELAY COMPENSATION - A modulation system comprising a signal processing unit and a modulator. The signal processing unit may generate a low frequency modulator signal, a high frequency modulator signal, and a modulator amplitude control signal. The modulator may generate a modulated signal for transmission via a wireless network based, at least in part, on the low frequency modulator signal, the high frequency modulator signal, and the modulator amplitude control signal. The signal processing unit comprises a delay compensation unit for delaying the generation of the high frequency modulator signal and the modulator amplitude control signal based, at least in part, on signal generation and modulation path delays associated with the low frequency modulator signal to substantially align the modulator signals at the output of the modulation system. | 12-17-2009 |
| 20090311972 | SYNTHESIZER AND MODULATOR FOR A WIRELESS TRANSCEIVER - A transceiver including a transmit modulator and a receiver. The modulator may accept a channel selection input, a first modulation input, a second modulation input, and an amplitude input. During transmit time slots, the modulator may generate a modulated output having a carrier frequency selected by the channel selection input. The carrier frequency may be frequency modulated by the first modulation inputs, phase modulated by the second modulation input, and amplitude modulated by the amplitude input. During receive time slots, the modulator may generate a carrier frequency selected by the channel selection input and offset by the first modulation input. The modulator may alternate between providing modulated transmit signals during transmit time slots and providing a local oscillator for the receiver during receive time slots. | 12-17-2009 |
| 20090285279 | PHASE FREQUENCY DETECTOR WITH PULSE WIDTH CONTROL CIRCUITRY - A phase frequency detector comprising a detection circuit and a reset circuit. The phase frequency detector may receive a feedback signal having a predetermined pulse width. The detection circuit may generate a first control signal based on a reference signal, and a second control signal based on the feedback signal. The reset circuit may generate a reset signal used for resetting the detection circuit based on the first control signal, the second control signal, and the feedback signal. The feedback signal may be tied to the generation of the reset signal such that, during a locked state, the pulse width of the second control signal is approximately equal to the pulse width of the feedback signal, which helps reduce the sensitivity of the circuit to nonlinearities. | 11-19-2009 |
| 20090072910 | VOLTAGE-CONTROLLED OSCILLATOR WITH CONTROL RANGE LIMITER - A voltage-controlled oscillator (VCO) comprising a first circuit, a second circuit, a comparator circuit, and a control unit. The first circuit can determine an output common mode voltage associated with an output of the VCO. The second circuit can generate an upper control voltage limit and a lower control voltage limit associated with a control voltage received by the VCO based, at least in part, on the output common mode voltage. The comparator circuit can compare the control voltage to the upper and lower control voltage limits. The control unit can determine whether to change a switched capacitance associated with the VCO based, at least in part, on whether the control voltage is outside the upper and lower control voltage limits, thereby maintaining an optimal region of operation for the control voltage. | 03-19-2009 |
| 20080248759 | Apparatus For Coupling A Wireless Communication Device To A Physical Device - A wireless communication device may be configured to transmit and receive data through a physical device, such as a cable. Relatively higher transmit radio frequency (RF) signals from the wireless communication device may be shifted to a relatively lower frequency, thereby enabling the relatively lower frequency signals to be carried by the physical device. Similarly, relatively lower frequency signals from the physical device may be shifted to relatively higher frequencies, thereby enabling the wireless communication device to receive the signals from the physical device. In one embodiment, the frequency of the RF signals may be between 2.3 and 2.7 GHz and the frequency of the relatively lower frequency shifted signals may be between 900 and 1100 MHz. | 10-09-2008 |
