Keying

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

Method and apparatus for signal detection in ultra wide-band communications

Abstract: Methods and apparatus for detecting ultra wide-band signals using circuitry having nonlinear dynamics characteristics are disclosed. The receiver circuit can be implemented using a simple tunnel diode or using an op-amp to provide dynamic characteristics. The detector can be used in a variety of modulation schemes, including but not limited to an ON-OFF keying scheme, an M-ary pulse position modulation scheme, and a pulse width modulation scheme. The approach requires only a single frame to detect the signal.

Coherent OCDMA system using DPSK data format with balanced detection

Abstract: In this letter, the application of differential phase-shift keying data format in coherent optical code-division multiple-access (DPSK-OCDMA) has been proposed and investigated theoretically and experimentally to combat noise in the OCDMA system. The DPSK-OCDMA can also ease the receiver's threshold level setting and enhance the system confidentiality.

Dynamic Adaptation of Projected Imperceptible Codes

Abstract: In this paper we present an innovative adaptive imperceptible pattern projection technique that takes into account parameters of human visual perception. A coded image is temporally integrated into the projected image, which is invisible to the human eye but can be reconstructed by a synchronized camera. The embedded code is dynamically adjusted on the fly to guarantee its imperceptibility and to adapt it to the current camera pose. Linked with real-time flash keying, for instance, this enables in-shot optical tracking using a dynamic multi-resolution marker technique. A sample prototype has been realized that demonstrates the application of our method in the context of augmentations in television studios.

WDM transmission at 6-Tbit/s capacity over transatlantic distance, using 42.7-Gb/s differential phase-shift keying without pulse carver

Abstract: We report the transmission of a record 6 Tbit/s capacity over 6,120 km distance, involving channels modulated at 42.7 Gb/s bit-rate with differential phase-shift keying (DPSK). The performance is found similar to DPSK with subsequent pulse carving, namely RZ-DPSK.

Transmission Performance Simulation Study Evaluation for High Speed Radio Over Fiber Communication Systems

Abstract: Radio over fiber communication system technology modulation techniques are presented in this study in order to enhance the performance behavior of optical fiber communication systems. The proposed modulation techniques used to meet this aim mainly consist from a mixture of traditional modulation technologies. The proposed modulation technologies include merging modulation techniques such as pulse amplitude frequency modulation, quadrature amplitude frequency modulation, differential phase shift keying amplitude modulation, offset quadrature phase shift keying amplitude modulation and frequency phase modulation are applied on different optical communication system models. The different types of modulation techniques are illustrated and discriminated in current research paper that provides measured quantities details that namely received power, maximum Q-factor and minimum bit error rate regarding to simulation results. Optiwave Simulation Version 13 software is the basic tool which is used to study proposed models.