Institution
Qualcomm
Company•Farnborough, United Kingdom•
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..
Papers published on a yearly basis
Papers
More filters
••
TL;DR: IBC, or intra picture block compensation, also named current picture referencing (CPR) in HEVC SCC, is introduced and discussed, and results show that up to 50% BD rate reduction in all intra coding can be achieved with intra block copy enabled, compared to the HEVC reference encoder without this tool.
Abstract: With the emerging applications such as online gaming and Wi-Fi display, screen content video, including computer generated text, graphics and animations, becomes more popular than ever. Traditional video coding technologies typically were developed based on models that fit into natural, camera-captured video. The distinct characteristics exhibited between these two types of contents necessitate the exploration of coding efficiency improvement given that new tools can be developed specially for screen content video. The HEVC Screen Content Coding Extensions (HEVC SCC) have been developed to incorporate such new coding tools in order to achieve better compression efficiency. In this paper, intra block copy (IBC, or intra picture block compensation), also named current picture referencing (CPR) in HEVC SCC, is introduced and discussed. This tool is very efficient for coding of screen content video in that repeated patterns in text and graphics rich content occur frequently within the same picture. Having a previously reconstructed block with equal or similar pattern as a predictor can effectively reduce the prediction error and therefore improve coding efficiency. Simulation results show that up to 50% BD rate reduction in all intra coding can be achieved with intra block copy enabled, compared to the HEVC reference encoder without this tool. Significant BD rate reductions for other coding configurations are also observed.
146 citations
••
TL;DR: Link power budgets for the TerraLink systems are presented, and link margin data are shown that quantitatively describe how the effective laser link range varies in different weather conditions.
Abstract: The TerraLink laser communication (lasercom) system was developed as a cost-effective, high-bandwidth, wireless alternative to fiber optic transmission. The advantages of lasercom over fiber optic cabling are primarily economic. However, free-space lasercom is subject to atmospheric effects, such as attenuation and scintillation, which can reduce link availability and may introduce burst errors not seen in fiber transmission. The TerraLink transceivers use large receive apertures and multiple transmit beams to reduce the effects of scintillation. By designing the lasercom link with sufficient margin for atmospheric attenuation and scintillation, a bit error rate (BER) of 1029 or better can be achieved. Since we designed the TerraLink transceivers to be eye-safe at the transmit aperture, each system is range-limited. Link power budgets for the TerraLink systems are presented, and link margin data are shown that quantitatively describe how the effective laser link range varies in different weather conditions. Since the TerraLink transceivers act as simple repeaters, they are protocol-independent. Examples of TerraLink installations transmitting wireless fast ethernet (125 Mbits/s), fiber distributed data interface (FDDI) (125 Mbits/s), asynchronous transfer mode (ATM) (155 and 622 Mbits/s), and Enterprise Systems Connection (ESCON) (200 Mbits/s) protocol data are presented.
146 citations
•
17 Feb 1995TL;DR: In this article, the output power of a radiotelephone operating in a cellular system in the preferred embodiment is controlled by power detection and a correction accumulator that together generate a gain control signal.
Abstract: The process and apparatus of the present invention limits the output power of a radiotelephone, operating in a cellular system in the preferred embodiment. This ensures the transmitted sidebands and synthesizer phase noise remains within a certain specification. This is accomplished by power detection and a correction accumulator that together generate a gain control signal by limiting the gain adjustment to a maximum value, even when the cell site communicating with the radiotelephone is sending power turn-up commands to the radiotelephone. This process includes dynamically correcting the output level of the transmitter due to gain variations in the transmitter stages or gain control elements.
145 citations
•
14 Apr 2003TL;DR: In this paper, a method to predict the timing of transmission of a basestation in a cellular communication system is presented, where the first and second time tags are determined using at least one satellite positioning system signal received at a mobile station which receives the corresponding time marker.
Abstract: Methods and apparatuses for frequency synchronizing basestations in a cellular communication system. In one aspect of the invention, a method to predict a timing of transmission of a basestation in a cellular communication system includes: receiving a first time tag for a first timing marker in a first cellular signal transmitted from the basestation; receiving a second time tag of a second timing marker in a second cellular signal transmitted from the basestation; and computing a frequency related to the basestation using the first and second time tags. Each of the time tags are determined using at least one satellite positioning system signal received at a mobile station which receives the corresponding time marker.
145 citations
•
01 Jun 2006TL;DR: In this article, a list-sphere decoding design in a multiple-input-multiple-output (MIMO) wireless communication environment is described, where the optimal rank selection and CQI computation for an optimal rank can be performed in conjunction with a non-linear receiver, such as a maximum life (ML) MMSE receiver, a nonlinear receiver with a list sphere decoder, and the like.
Abstract: Systems and methodologies are described that facilitate integrating a list-sphere decoding design in a multiple input-multiple output (MIMO wireless communication environment According to various aspects, optimal rank selection and CQI computation for an optimal rank can be performed in conjunction with a non-linear receiver, such as a maximum life (ML) MMSE receiver, a non-linear receiver with a list-sphere decoder, and the like Optimal rank selection can be performed using a maximum rank selection protocol, a channel capacity-based protocol, or any other suitable protocol that facilitates rank selection, and CQI information can be generated based in part on effective SNRs determined with regard to a selected optimal rank
145 citations
Authors
Showing all 19413 results
Name | H-index | Papers | Citations |
---|---|---|---|
Jian Yang | 142 | 1818 | 111166 |
Xiaodong Wang | 135 | 1573 | 117552 |
Jeffrey G. Andrews | 110 | 562 | 63334 |
Martin Vetterli | 105 | 761 | 57825 |
Vinod Menon | 101 | 269 | 60241 |
Michael I. Miller | 92 | 599 | 34915 |
David Tse | 92 | 438 | 67248 |
Kannan Ramchandran | 91 | 592 | 34845 |
Michael Luby | 89 | 282 | 34894 |
Max Welling | 89 | 441 | 64602 |
R. Srikant | 84 | 432 | 26439 |
Jiaya Jia | 80 | 294 | 33545 |
Hai Li | 79 | 570 | 33848 |
Simon Haykin | 77 | 454 | 62085 |
Christopher W. Bielawski | 76 | 334 | 32512 |