Search for dissertations about: "free-space optical communications"

Showing result 1 - 5 of 6 swedish dissertations containing the words free-space optical communications.

2. 1. Signaling for Optical Intensity Channels

   Author : Johnny Karout; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lattice codes; mutual information; intensity modulation; noncoherent communications; Direct detection; sphere packing.; infrared communications; free-space optical communications; fiber-optical communications;

   Abstract : With the growing popularity of social media services, e-commerce, and many other internet-based services, we are witnessing a rapid growth in the deployment of data centers and cloud computing platforms. As a result, the telecommunications industry has to continue providing additional network capacity to meet the increasing demand for bandwidth. READ MORE

4. 2. Phase Sensitive Amplifiers for Free-Space Optical Communications

   Author : Ravikiran Kakarla; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phase sensitive amplifier; sensitivity; optical injection locking; noisefigure;

   Abstract : The demand for high data rate free-space communications is increasing due to the planned future space exploration missions. In the next few years there is a need to increase the speed by 100 times according to NASA, and this necessitates that transmission systems operate at higher carrier frequencies. READ MORE

5. 3. Modulation Optimization for Noncoherent Optical Systems

   Author : Johnny Karout; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Direct detection; noncoherent communications; lattice codes; mutual information; fiber-optical communications; intensity modula- tion; sphere packing.; infrared communications; free-space optical communications;

   Abstract : There has been a significant improvement in high-speed electronics and optical components over the past few years, and this is one of the key enabling factors for high data rate transmission. Moreover, multi- level modulation formats, which encode information onto the carrier’s amplitude and phase, are necessary to increase the spectral efficiency of communication systems. READ MORE

6. 4. Ultralow noise pre-amplified receiver for free-space optical communications

   Author : Ravikiran Kakarla; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sensitivity; noise figure; optical injection locking; Phase sensitive amplifier;

   Abstract : The demand for high data rate in space communication links is increasing due to the growth of space exploration missions inter-satellite, and satellite-to-Earth data transmission. Optical communication systems capable of handling hundreds of Gigabits per second data transmission with a single light carrier and are suitable for such space links. READ MORE

7. 5. Experimental multiuser secure quantum communications

   Author : Jan Bogdanski; Mohamed Bourennane; Nobuyuki Imoto; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Quantum key distribution; multiparty quantum secret sharing; Sagnac interferometer; “plug play” QKD; Passive Optical Network PON ; decoy states; single mode fiber birefringence compensation; quantum bit error rate; visibility; Physics; Fysik; fysik; Physics;

   Abstract : We are currently experiencing a rapid development of quantum information, a new branch of science, being an interdisciplinary of quantum physics, information theory, telecommunications, computer science, and many others. This new science branch was born in the middle of the eighties, developed rapidly during the nineties, and in the current decade has brought a technological breakthrough in creating secure quantum key distribution (QKD), quantum secret sharing, and exciting promises in diverse technological fields. READ MORE