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Visar resultat 1 - 5 av 83 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Frequency Noise in Coherent Optical Systems: Impact and Mitigation Methods

   Författare :Aditya Kakkar; Richard Schatz; Sergei Popov; Gunnar Jacobsen; Xiaodan Pang; Oskars Ozolins; Magnus Karlsson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Equalization enhanced phase noise; frequency noise; coherent optical communications; carrier phase recovery; carrier phase estimation; circular quadrature amplitude modulation; EEPN; CmQAM; blind phase search; phase noise;

   Sammanfattning : The increase in capacity demand along with the advancement in digital signal processing (DSP) have recently revived the interest in coherent optical communications and led to its commercialization. However, design and development of robust DSP algorithms for example for carrier phase recovery (CPR) becomes complex as we opt for high order modulation formats such as 16QAM and beyond. LÄS MER

3. 2. Low noise frequency combs and injection locking for broadly tunable laser sources and tomography

   Författare :Connor Skehan; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; relative intensity noise; frequency comb; frequency noise; phase noise; optical injection locking;

   Sammanfattning : Lasers have revolutionized the world of physics by providing a highly coherent source of photons which may be used for a large variety of purposes. Here, we study the noise properties of frequency combs - a special class of frequency stabilized and mutually coherent multi-mode lasers, as well as the optical injection locking of comb tones as a means for low noise amplification and tone selection. LÄS MER

4. 3. Phase Noise Tolerant Modulation Formats and DSP Algorithms for Coherent Optical Systems

   Författare :Jaime Rodrigo Navarro; Sergei Popov; Gunnar Jacobsen; Richard Schatz; Xiaodan Pang; Oskars Ozolins; Gabriella Bosco; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical communications; carrier phase recovery; blind phase search; circular quadrature amplitude modulation; CmQAM; coherent optical communications; digital signal processing; carrier phase estimation; equalization enhanced phase noise; EEPN; Telecommunication; Telekommunikation;

   Sammanfattning : Coherent detection together with multilevel modulation formats has the potential to significantly increase the capacity of existing optical communication systems at no extra cost in signal bandwidth. However, these modulation formats are more susceptible to the impact of different noise sources and distortions as the distance between its constellation points in the complex plane reduces with the modulation index. LÄS MER

5. 4. Phase-Noise Compensation for Space-Division Multiplexed Multicore Fiber Transmission

   Författare :Arni Alfredsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; detection; estimation; space-division multiplexing.; phase noise; multicore fiber; Coherent fiber-optic communications;

   Sammanfattning : The advancements of popular Internet-based services such as social media, virtual reality, and cloud computing constantly drive vendors and operators to increase the throughput of the Internet backbone formed by fiber-optic communication systems. Due to this, space-division multiplexing (SDM) has surfaced as an appealing technology that presents an opportunity to upscale optical networks in a cost-efficient manner. LÄS MER

7. 5. Coherent Optical Transmission Systems : Performance and Coding Aspects

   Författare :Miu Yoong Leong; Sergei Popov; Gunnar Jacobsen; Enrico Forestieri; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Since the invention of fiber-optic systems in the 1970s, user demand has driven innovation forward, and each new generation of products has achieved higher data rates than its predecessor. Today, the most promising approach for further increasing data rates is coherent transmission with multi-level modulation and digital signal processing (DSP). LÄS MER