Keying

About: Keying is a research topic. Over the lifetime, 6598 publications have been published within this topic receiving 82943 citations.

Real time video conferencing system and method with multilayer keying of multiple video images

Abstract: A video conferencing system and method that uses a central multimedia bridge to combine multimedia signals from a plurality of conference participants into a single composite signal for each participant. The system gives each conference participant the ability to customize their individual display of other participants, including keying in and out selected portions of the display and overlapping displayed images, and the ability to identify individual images in a composed video stream by click and drag operations or the like. The system uses a chain of video composing modules that can be extended as necessary to combine video signal streams from any number of conference participants in real time. Multimedia association software is provided for associating different media types to enhance display and manipulation capabilities for multimedia uses. The system also allows each user to dynamically change who can receive the information they provide to the conference.

A Universal Space-Time Architecture for Multiple-Antenna Aided Systems

Abstract: In this tutorial, we first review the family of conventional multiple-antenna techniques, and then we provide a general overview of the recent concept of the powerful Multiple-Input Multiple-Output (MIMO) family based on a universal Space-Time Shift Keying (STSK) philosophy. When appropriately configured, the proposed STSK scheme has the potential of outperforming conventional MIMO arrangements.

Limits to long-haul coherent transmission set by the Kerr nonlinearity and noise of the in-line amplifiers

Abstract: The effect of Kerr nonlinearity and noise of the erbium amplifiers is investigated in a link in which dispersion is zero to all orders. The analytical expressions for the error probability at the receiver are found for a differential phase shift keying modulation format. The role of the total bandwidth of the amplified spontaneous emission noise is discussed. >

Undersampled Phase Shift ON-OFF Keying for Camera Communication

Abstract: In this paper, an optical camera communication system utilizing the under-sampled phase shift ON-OFF keying modulation is proposed to support non-flickering visible light communication. This system sends three types of light symbols through light emitting diode (LED) lamps, which are recorded by a camera. By employing a dual LED lamp with a designated mapping and framing method, the data rate can reach up to 3 times of the camera's frame rate. The experiment results show that the proposed camera communication system can achieve 150 bps error-free communications for a range up to 12 m.

Computer system for protecting software and a method for protecting software

Abstract: A method for protecting an item of software, wherein at least one first challenge means is associated with said protected item of software, and at least one first response means accesses one private keying material. At least a third means (either challenge or response also exists). The first challenge means has no access to the said private keying material. The first response means proves to the first challenge means that the first response means has access to the private keying material. The first challenge means validates this proof using the public keying material that corresponds to the first response means' private keying material.