Qualcomm

About: Qualcomm is a company organization based out in Farnborough, United Kingdom. It is known for research contribution in the topics: Wireless & Signal. The organization has 19408 authors who have published 38405 publications receiving 804693 citations. The organization is also known as: Qualcomm Incorporated & Qualcomm, Inc..

Wlan system scanning and selection

Abstract: Techniques for performing WLAN system scanning and selection are described. A terminal performs multiple iterations of scan to detect for WLAN systems. A scan list containing at least one WLAN system to detect for is initially determined. For each scan iteration, a scan type may be selected from among the supported scan types. The selected scan type may indicate passive scan or active scan, frequency channels to scan, etc. A scan may be performed based on the selected scan type. Signal strength measurements are obtained for access points received during the scan and used to identify detected access points. After all scan iterations are completed, candidates access points are identified based on the scan results, e.g., based on the signal strength measurements for the detected access points and a detection threshold. The best candidate access point may be selected for association by the terminal.

Method and apparatus for determining data rate of transmitted variable rate data in a communications receiver

Abstract: A system for determining the rate at which data has been encoded in the receiver of a variable-rate communications system The data is received in frames having a fixed number of symbols Multiple copies of symbols fill the frame when data is encoded at less than the full rate At an encoding rate of one fourth the full rate, for example, each symbol in the frame is repeated four times The incoming symbols are provided to multiple paths for decoding Each path decodes the symbols at one of the possible rates Error metrics, which describe the quality of the decoded symbols, are extracted and provided to a processor The error metrics may include Cyclic Redundancy Check (CRC) results, Yamamoto Quality Metrics, and Symbol Error Rates The processor analyzes the error metrics and determines the most probable rate at which the incoming symbols were encoded

Method and apparatus for controlling transmit power thresholds based on classification of wireless communication subscribers

Abstract: The present invention provides a method and apparatus for allowing a base station or base station controller to adjust transmissions to fixed location subscribers in closed-loop communication systems. In a closed-loop communication system, a base station exchanges signals with both fixed location and mobile user stations. When a user or subscriber initially registers with the base station, the base station determines a status of this subscriber based on, for example, an electronic serial number transmitted to the base station. The base station compares the electronic serial number to a database (Home Location Register) which determines whether the user corresponds to a fixed station or a mobile station. If the user is a fixed station, then the base station lowers nominal and minimum power level thresholds. Based on the lowered thresholds, the base station thereafter transmits forward link signals to the fixed station at a lower power level. As a result, the base station can increase its capacity due to the lower overall power rate.

Method and system for packaging a MEMS device

Abstract: A MEMS-based display device is described, wherein an array of interferometric modulators are configured to reflect light through a transparent substrate. The transparent substrate is sealed to a backplate and the backplate can contain electronic circuitry for controlling the array of interferometric modulators. The backplate can provide physical support for device components, such as electronic components which can be used to control the state of the display. The backplate can also be utilized as a primary structural support for the device.

Iterative Methods for Cancellation of Intercarrier Interference in OFDM Systems

Abstract: We consider orthogonal frequency-division multiplexing systems with intercarrier interference (ICI) due to insufficient cyclic prefix and/or temporal variations Intersymbol interference (ISI) and ICI lead to an error floor in conventional receivers We suggest two techniques for the equalization of ICI The first, called "operator-perturbation technique" is an iterative technique for the inversion of a linear system of equations Alternatively, we show that serial or parallel interference cancellation can be used to drastically reduce the error floor Simulations show that, depending on the SNR and the origin of the ICI, one of the schemes performs best In all cases, our schemes lead to a drastic reduction of the bit error rate