Showing papers by "Qualcomm published in 2008"

Modern Coding Theory

Abstract: Having trouble deciding which coding scheme to employ, how to design a new scheme, or how to improve an existing system? This summary of the state-of-the-art in iterative coding makes this decision more straightforward. With emphasis on the underlying theory, techniques to analyse and design practical iterative coding systems are presented. Using Gallager's original ensemble of LDPC codes, the basic concepts are extended for several general codes, including the practically important class of turbo codes. The simplicity of the binary erasure channel is exploited to develop analytical techniques and intuition, which are then applied to general channel models. A chapter on factor graphs helps to unify the important topics of information theory, coding and communication theory. Covering the most recent advances, this text is ideal for graduate students in electrical engineering and computer science, and practitioners. Additional resources, including instructor's solutions and figures, available online: www.cambridge.org/9780521852296.

Gaussian Interference Channel Capacity to Within One Bit

Abstract: The capacity of the two-user Gaussian interference channel has been open for 30 years. The understanding on this problem has been limited. The best known achievable region is due to Han and Kobayashi but its characterization is very complicated. It is also not known how tight the existing outer bounds are. In this work, we show that the existing outer bounds can in fact be arbitrarily loose in some parameter ranges, and by deriving new outer bounds, we show that a very simple and explicit Han-Kobayashi type scheme can achieve to within a single bit per second per hertz (bit/s/Hz) of the capacity for all values of the channel parameters. We also show that the scheme is asymptotically optimal at certain high signal-to-noise ratio (SNR) regimes. Using our results, we provide a natural generalization of the point-to-point classical notion of degrees of freedom to interference-limited scenarios.

Microwave Assisted Magnetic Recording

Abstract: In this paper, we present a novel mechanism for recording at a head held significantly below the medium coercivity in a perpendicular recording geometry. By applying a localized ac field at adequate frequency to the perpendicular recording medium, saturation recording can be achieved with recording field amplitudes significantly below the medium coercivity, or the medium perpendicular anisotropy field. A scheme utilizing spin torque to generate a localized ac field at high frequency (tens of gigahertz) with kilo-oersted field amplitude in the medium is proposed along with a systematic modeling analysis. Recording simulations at high linear densities are presented.

Cooperative communications with relay-selection: when to cooperate and whom to cooperate with?

Abstract: In this paper; we propose a new cooperative communication protocol, which achieves higher bandwidth efficiency while guaranteeing the same diversity order as that of the conventional cooperative schemes. The proposed scheme considers relay selection via the available partial channel state information (CSI) at the source and the relays. In particular, we discuss the multi-node decode-and-forward cooperative scenarios, where arbitrary N relays are available. The source determines when it needs to cooperate with one relay only, and which relay to cooperate with in case of cooperation, i.e., "When to cooperate?" and "Whom to cooperate with?". An optimal relay is the one which has the maximum instantaneous scaled harmonic mean functionof its source-relay and relay-destination channel gains. For the symmetric scenario, we derive an approximate expression of the bandwidth efficiency and obtain an upper bound on the symbol error rate (SER) performance. We show that full diversity is guaranteed and that a significant increase of the bandwidth efficiency is achieved. Moreover, we present the tradeoff between the achievable bandwidth efficiency and the corresponding SER. Finally, the obtained analytical results are verified through computer simulations.

Energy-Efficient Cooperative Relaying over Fading Channels with Simple Relay Selection

Abstract: We consider a cooperative wireless network where a set of nodes cooperate to relay in parallel the information from a source to a destination using a decode-and-forward approach. The source broadcasts the data to the relays, some or all of which cooperatively beamform to forward the data to the destination. We generalize the standard approaches for cooperative communications in two key respects: (i) we explicitly model and factor in the cost of acquiring channel state information (CSI), and (ii) we consider more general selection rules for the relays and compute the optimal one among them. In particular, we consider simple relay selection and outage criteria that exploit the inherent diversity of relay networks and satisfy a mandated outage constraint. These criteria include as special cases several relay selection criteria proposed in the literature. We obtain expressions for the total energy consumption for general relay selection and outage criteria for the non-homogeneous case, in which different relay links have different mean channel power gains, and the homogeneous case, in which the relay links statistics are identical. We characterize the structure of the optimal transmission scheme. Numerical results show that the cost of training and feedback of CSI is significant. The optimal strategy is to use a varying subset (and number) of relay nodes to cooperatively beamform at any given time. Depending on the relative location of the relays, the source, and the destination, numerical computations show energy savings of about 16% when an optimal relay selection rule is used. We also study the impact of shadowing correlation on the energy consumption for a cooperative relay network.

Biological effects of magnetic power transfer

Abstract: System and method for wireless power transfer based on values set to comply with limits from multiple different agencies.

Method and apparatus for distribution and personalization of e-coupons

Abstract: A method and system for distributing and personalizing E-Coupons include sending a generic E-Coupon identifier to a mobile device and requesting a redeemable personalized E-Coupon based on the generic E-Coupon identifier. User location, time, purchase history and preference may be provided and used to personalize the E-Coupon. The personalized E-Coupon may then be distributed to the mobile device. The generic E-Coupon identifier may be distributed through different media, such as audio, video, multimedia or wireless data networks. For high security devices, the personalized E-Coupon may be sent digitally signed. For low security devices, the E-Coupon Manager may store the personalized E-Coupon and send to the mobile device a unique E-Coupon ID. The distributed personalized E-Coupons may be used to receive discounts at a merchant physical location or Internet site.

Enhanced interface for voice and video communications

Abstract: An enhanced interface for voice and video communications, in which a gesture of a user is recognized from a sequence of camera images, and a user interface is provided include a control and a representation of the user. The process also includes causing the representation to interact with the control based on the recognized gesture, and controlling a telecommunication session based on the interaction.

Rate Region of the Quadratic Gaussian Two-Encoder Source-Coding Problem

Abstract: We determine the rate region of the quadratic Gaussian two-encoder source-coding problem. This rate region is achieved by a simple architecture that separates the analog and digital aspects of the compression. Furthermore, this architecture requires higher rates to send a Gaussian source than it does to send any other source with the same covariance. Our techniques can also be used to determine the sum-rate of some generalizations of this classical problem. Our approach involves coupling the problem to a quadratic Gaussian ldquoCEO problem.rdquo

Management of dynamic electronic coupons

Abstract: Providing for management of a dynamic mobile coupon (DMC) at a mobile device is described herein. Particularly, dynamic characteristics associated with the DMC, such as a redeemable value, can be utilized to browse, sort, search, recall, or redeem the DMC utilizing a user interface of the mobile device. In other aspects, a DMC management application can interact with server components to backup and store DMC data, synchronize dynamic information (e.g., a dynamic redeemable value), access or manage a user profile, interface with other mobile devices to accomplish sharing, trading, exchanging, selling the DMC, and so on. Accordingly, provided is an efficient and personable way to manage mobile coupons in a mobile operating environment and provide increased value and utility for a user of such coupons.

Multicell downlink capacity with coordinated processing

Abstract: We study the potential benefits of base-station (BS) cooperation for downlink transmission in multicell networks. Based on a modified Wyner-type model with users clustered at the cell-edges, we analyze the dirty-paper-coding (DPC) precoder and several linear precoding schemes, including cophasing, zero-forcing (ZF), and MMSE precoders. For the nonfading scenario with random phases, we obtain analytical performance expressions for each scheme. In particular, we characterize the high signal-to-noise ratio (SNR) performance gap between the DPC and ZF precoders in large networks, which indicates a singularity problem in certain network settings. Moreover, we demonstrate that the MMSE precoder does not completely resolve the singularity problem. However, by incorporating path gain fading, we numerically show that the singularity problem can be eased by linear precoding techniques aided with multiuser selection. By extending our network model to include cell-interior users, we determine the capacity regions of the two classes of users for various cooperative strategies. In addition to an outer bound and a baseline scheme, we also consider several locally cooperative transmission approaches. The resulting capacity regions show the tradeoff between the performance improvement and the requirement for BS cooperation, signal processing complexity, and channel state information at the transmitter (CSIT).

Enhanced input using recognized gestures

Abstract: A representation of a user can move with respect to a graphical user interface based on input of a user. The graphical user interface comprises a central region and interaction elements disposed outside of the central region. The interaction elements are not shown until the representation of the user is aligned with the central region. A gesture of the user is recognized, and, based on the recognized gesture, the display of the graphical user interface is altered and an application control is outputted.

Improved h.264 intra coding based on bi-directional intra prediction, directional transform, and adaptive coefficient scanning

Abstract: In this paper, a novel intra coding scheme is proposed. The proposed scheme improves H.264 intra coding from three aspects: 1) H.264 intra prediction is enhanced with additional bi-directional intra prediction modes; 2) H.264 integer transform is supplemented with directional transforms for some prediction modes; and 3) residual coefficient coding in CAVLC is improved. Compared to H.264, together the improvements can bring on average 7% and 10% coding gain for CABAC and for CAVLC, respectively, with average coding gain of 12% for HD sequences.

Wireless Power Bridge

Abstract: A wireless power bridge that allows magnetic transmission of energy across a solid barrier such as a wall. A circuit is described for controlling the operation.

Virtual sim card for mobile handsets

Abstract: A system and method for providing a capability to backup cellular telephone provisioning information and personal data from a mobile handset on a server. A user initializes an account with a service provider with authentication credentials and backs up provisioning information and personal data stored within a mobile handset to server for safe keeping. The provisioning information and personal data can be accessed via the cellular telephone network so that the provisioning and personal data can be transferred among mobile handsets. This allows a user to restore personal data quickly and easily if a mobile handset replaced, lost or destroyed. The system and method further provide the capability to remotely provision new mobile handsets.

Recommendation generation systems, apparatus, and methods

Abstract: A method for generating recommendations for a user of a mobile device is provided. The user is associated with a service provider. A request for a recommendation is obtained. Data associated with the user and data on the content available to the user is retrieved from the service provider. A list of recommendations is generated based on an analysis of the retrieved user data. The recommendations are generated by a plurality of different recommendation techniques.

Wireless Energy Transfer Using Coupled Antennas

Abstract: A power transmission system produces a magnetic field at a source that is wirelessly coupled to a receiver Both the source and receiver are capacitively coupled LC circuits, driven at or near resonance

Apparatus and Methods for Locating, Tracking and/or Recovering a Wireless Communication Device

Abstract: Methods, systems, devices and computer program products are provided for locating, tracking and/or recovering a wireless communication device that has been misplaced, lost or stolen. In addition, the aspects provide for tracking or surveillance of the location or user in instances in which the wireless device has been loaned or is being used for covert surveillance. The aspects include communicating a locating state code to the targeted device, which detects the code and executes one or more routines that are associated with the respective code. In this regard, the targeted device is capable of carrying out different routines or sequences of actions depending on the state of the device, such as a misplaced state, a lost state, a stolen state or the like, which is based on the respective code.

Beamforming in mimo systems

Abstract: A beamforming method comprises transmitting a training sequence from a transmitter array employing a set of beamforming vectors from a beamforming codebook. A receive array employs a combining codebook to acquire channel state information from the received transmissions, and estimates a preferred beamforming vector and a preferred combining vector. At least the preferred beamforming vector (and, optionally, the preferred combining vector) is transmitted back to the transmitter array.

Flexible DTX and DRX in a wireless communication system

Abstract: A data traffic responsive battery-saving approach for a wireless user equipment (UE) device such as an data packet capable cellphone incorporates flexible discontinuous transmission and reception (DTX-DRX) when in Long Term Evolution (LTE) active mode as dictated by an evolved radio access network (RAN) such as an evolved base node (eNode B). A UE device requests are made on unsynchronized random access channel (RACH). Lengthening a duration of DRX and reducing requirements for synchronization uplink transmissions results in power savings of up to 75%, as well as creating opportunities for reducing interference and for allocating additional time slots for data. This power savings is compatible with other downlink scheduling proposals, with control channel-less Voice-over-IP (VoIP), and need not target those UE devices in bad radio conditions. Legacy UE devices that can interact with the eNode B by being capable of radio resource control (RRC) signaling continue to be compatible.

Enhanced character input using recognized gestures

Abstract: Enhanced character input using recognized gestures, in which a user's first and second gestures are recognized, and a control including radially disposed interaction elements is output. At least a portion of the interaction elements are associated with clusters of characters. When an interaction element is selected, the characters associated with the selected interaction element are disposed radially in relation to the selected interaction element. Using the control, the interaction element and a character associated with the selected interaction element are selected based on the user's recognized first and second gestures, respectively, and the selected character is output.

High Efficiency and Power Transfer in Wireless Power Magnetic Resonators

Abstract: Techniques for wireless power transmission at levels that induce high power transfer and/or high efficiency of coupling.

Wireless power system and proximity effects

Abstract: A wireless powering and charging system is described. Such a system comprises a radio frequency transmitter (typically a home-appliance sized unit on a desk or a shelf) and a receiver (typically a small mobile unit carried by the user). When the user is in range of the transmitter, charging or powering can take place in the mobile unit.

Method and system for context dependent pop-up menus

Abstract: A method and system for providing context dependent pop-up menu icons that activate menu icons in response to a select & drag operation by manipulation of a pointing device. Presented icons may correspond to functions or actions that can be implemented with the particular type of content selected. Icons may be displayed in a consistent manner in terms of position and content with respect to the selected file or object. Icons may appear only during a select & drag operation, thereby leaving the display uncluttered at other times. Presentation of icons may be discontinued when the selected file or object is dragged beyond the area of the presented icons. New applications can register with the operating system to specify icons to be presented when corresponding files are selected or when particular content objects are selected within the application.

Method and apparatus to create trust domains based on proximity

Abstract: Devices and methods use close range communication links, e.g., near field communication (NFC) links, to authenticate communication devices to one another to create or join a new device to a trust domain. Once two devices establish a close range communication peer-to-peer link the devices exchange credential information that provide an infrastructure for the trust domain. Medium or long range wireless or wired network communication links can then be used for secure and trusted communications. Proximity limits of the close range communication P2P link enables mutual trust to be presumed among devices, providing added security to the process of extending a trust domain and reducing the need for security and authentication signaling. Embodiments provide a variety of methods for extending credential infrastructure among devices. Embodiments further enable simple to use virtual cables that can provide secure point-to-point communications that are configured merely by touching two communication devices together.

Single-Ended and Differential Ka-Band BiCMOS Phased Array Front-Ends

Abstract: Single-ended and differential phased array front-ends are developed for Ka-band applications using a 0.12 mum SiGe BiCMOS process. The phase shifters are based on CMOS switched delay networks and have 22.5deg phase resolution and <4deg rms phase error at 35 GHz, and can handle +10 dBm of RF power (P1dB) with a 3rd order intermodulation intercept point (IIP3) of +21 dBm. For the single-ended design, a SiGe low noise amplifier is placed before the CMOS phase shifter, and the LNA/phase shifter results in 11 plusmn 1.5 dB gain and <3.4 dB of noise figure (NF), for a total power consumption of only 11 mW. For the differential front-end, a variable gain LNA is also developed and shows 9-20 dB gain and <1deg rms phase imbalance between the eight different gain states. The differential variable gain LNA/phase shifter consumes 33 mW, and results in 10 + 1.3 dB gain and 3.8 dB of NF. The gain variation is reduced to 9.1 plusmn 0.45 dB with the variable gain function applied. The single-ended and differential front-ends occupy a small chip area, with a size of 350 times 800 mum2 and 350 times 950 mum2, respectively, excluding pads. These chips are competitive with GaAs and InP designs, and are building blocks for low-cost millimeter-wave phased array front-ends based on silicon technology.

Dynamic electronic coupon for a mobile environment

Abstract: Dynamic mobile coupons (DMCs) having a variable commercial value and/or other variable coupon characteristic are provided herein. By way of example, a DMC can be distributed to a mobile device based on criteria established by a sponsor of the DMC. A redemption value of the DMC can be variable and dynamically established based at least in part on data associated with a recipient mobile device. Upon redemption of the DMC at a retail entity, the value is fixed and applied to a transaction. Details of the transaction are provided to a remote clearinghouse that performs mediation and indemnification functions to finalize the transaction. As described, the subject disclosure provides a DMC that facilitates a rich and flexible mechanism to generate purchasing incentive for consumers in a mobile environment.

Methods and apparatus for data exchange in peer to peer communications

Abstract: An exemplary wireless communications device comprises a processor coupled to a memory and a wireless communications interface. The processor is configured to transmit a first transmission symbol at a first time index from a first set of time indices, and to transmit a second transmission symbol at a second time index different from the first time index from the first set of time indices, a portion of the first transmission symbol and a portion of the second transmission symbol including the same data. The first set of time indices is associated with a first device ID and includes at least one time index not contained in a second set of time indices associated with a second device ID, and the second set includes at least one time index not contained in the first set.

Adaptive coefficient scanning for video coding

Abstract: This disclosure describes techniques for scanning coefficients of video blocks. In particular, the techniques of this disclosure adapt a scan order used to scan a two dimensional block of coefficients into a one dimensional coefficient vector based on statistics associated with one or more previously coded blocks. For example, statistics that indicate the likelihood that a given coefficient value in each position of a two dimensional block is zero or non zero may be collected for one or more previously coded blocks. At some point, an adjustment to the scan order can be made in order to better ensure that non-zero coefficients are grouped together near the front of the one dimensional coefficient vector, which can improve the effectiveness of entropy coding. The collection of statistics and adjustment of scan order may be made separately for each possible prediction mode.

Multi-sensor data collection and/or processing

Abstract: The subject matter disclosed herein relates to the control and utilization of multiple sensors within a device. For an example, motion of a device may be detected in response to receipt of a signal from a first sensor disposed in the device, and a power state of a second sensor also disposed in the device may be changed in response to detected motion.