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..

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 ``CEO problem.''

Cache-aided interference channels

Abstract: Over the past decade, the bulk of wireless traffic has shifted from speech to content. This shift creates the opportunity to cache part of the content in memories closer to the end users, for example in base stations. Most of the prior literature focuses on the reduction of load in the backhaul and core networks due to caching, i.e., on the benefits caching offers for the wireline communication link between the origin server and the caches. In this paper, we are instead interested in the benefits caching can offer for the wireless communication link between the caches and the end users. To quantify the gains of caching for this wireless link, we consider an interference channel in which each transmitter is equipped with an isolated cache memory. Communication takes place in two phases, a content placement phase followed by a content delivery phase. The objective is to design both the placement and the delivery phases to maximize the rate in the delivery phase in response to any possible user demands. Focusing on the three-user case, we show that through careful joint design of these phases, we can reap three distinct benefits from caching: a load balancing gain, an interference cancellation gain, and an interference alignment gain. In our proposed scheme, load balancing is achieved through a specific file splitting and placement, creating a particular pattern of content overlap at the caches. This overlap allows to implement interference cancellation. Further, it allows us to construct several virtual transmitters, each responsible for a part of the requested content, which increases interference alignment possibilities.

Optical interference color display and optical interference modulator

Abstract: An optical interference color display is provided. The optical interference color display comprises a color filtering substrate, a patterned support layer, a plurality of first electrodes, a plurality of optical films and a plurality of second electrodes. The patterned support layer and the first electrodes are positioned on the color filtering substrate with the patterned support layer between the first electrodes. The optical films are positioned on the first electrodes. The second electrodes is positioned over the first electrodes and supported through the patterned support layer such that an air gap with identical thickness is produce between every pair of second electrode and first electrode. Using the color filtering substrate to show color images, air gap between the first electrodes and the second electrodes are identical and hence simplifies the manufacturing process.

Method and apparatus for automatic gain control and DC offset cancellation in quadrature receiver

Abstract: An automatic gain control (AGC) and D.C. offset correction method and apparatus for controlling signal power of a received RF signal within a dual mode quadrature receiver is disclosed herein. The AGC apparatus includes an adjustable gain amplifier (18). A quadrature downconverter (20) coupled to the amplifier (18) serves to translate the frequency of the output signal to a baseband frequency which is offset by a predetermined margin from D.C. Two high gain active lowpass filters (76 and 78) provide out-of-band signal rejection for the baseband signals. A D.C. feedthrough suppression loop supresses D.C. offsets produced by a downconverter (20) and the lowpass filters (76 and 78). The AGC apparatus also generates a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and produces the gain control signal by integrating or by refraining from integration based on values of the reference, received power signal, and gain control signals.

Relay antenna indexing for shared antenna communication

Abstract: Providing for distributed processing for a set of wireless communication devices to implement distributed, multi-antenna communication via one or more of the devices is described herein. By way of example, a relay link can be established between one or more wireless transceivers. The link can be utilized to distribute an indexing parameter to a remote transceiver. The indexing parameter can be employed to identify a set of index-specific instructions configured for a particular wireless node of a network. Based on the instructions and indexing parameter, such transceiver can locally compute and transmit, or receive and decode, a stream of traffic data for the multi-antenna communication. Thus, for instance, a P-P link between UTs can be employed to implement increased throughput and reduced interference benefits of multi-antenna communication for unplanned configurations of mobile devices.