Digital signal processing for fiber-optic communication systems

dc.check.embargoformatNot applicableen
dc.check.infoNo embargo requireden
dc.check.opt-outNot applicableen
dc.check.reasonNo embargo requireden
dc.check.typeNo Embargo Required
dc.contributor.advisorZhao, Jianen
dc.contributor.advisorTownsend, Paul D.en
dc.contributor.advisorManning, Roberten
dc.contributor.authorOuyang, Xing
dc.contributor.funderScience Foundation Irelanden
dc.contributor.funderSeventh Framework Programmeen
dc.description.abstractAs the available bandwidth of optical fibers has been almost fully exploited, Digital Signal Processing (DSP) comes to rescue and is a critical technology underpinning the next generation advanced fiber-optic systems. Literally, it contributes two principal enforcements with respect to information communication. One is the implementation of spectrally-efficient modulation schemes, and the other is the guarantee of the recovery of information from the spectrally-efficient optical signals after channel transmission. The dissertation is dedicated to DSP techniques for the advanced fiber-optic systems. It consists of two main research topics. The first topic is about Fast-orthogonal frequency-division multiplexing (OFDM) — a variant OFDM scheme whose subcarrier spacing is half of that of conventional OFDM. The second one is about Fresnel transform with the derivation of an interesting discrete Fresnel transform (DFnT), and the proposal of orthogonal chirp-division multiplexing (OCDM), which is fundamentally underlain by the Fresnel transform. In the first part, equalization and signal recovery problems result from the halved subcarrier spacing in both double-sideband (DSB) and single-sideband (SSB) modulated Fast-OFDM systems are studied, respectively. By exploiting the relation between the multiplexing kernels of Fast-OFDM systems and Fourier transform, equalization algorithms are proposed for respective Fast-OFDM systems for information recovery. Detailed analysis is also provided. With the proposed algorithms, the DSB Fast-OFDM was experimentally implemented by intensity-modulation and direct detection in the conventional 1.55-μm and the emerging 2-μm fiber-optic systems, and the SSB Fast-OFDM was first implemented in coherent fiber-optic system with a spectral efficiency of 6 bit/s/Hz at 36 Gbps, for the first time. In the second part, Fresnel transform from optical Fresnel diffraction is studied. The discrete Fresnel transform (DFnT) is derived, as an interesting transformation that would be potentially useful for DSP. Its properties are proved. One of the attractive properties, the convolution-preservation property states that the DFnT of a circular convolution of two sequences is equal to the DFnT of either one convolving with the other. One application of DFnT is practically utilized in the proposal of OCDM. In the OCDM system, a large number of orthogonal chirped waveforms are multiplexed for high-speed communication, achieving the maximum spectral efficiency of chirp spread spectrum systems, in the same way as OFDM attains the maximum spectral efficiency of frequency-division multiplexing. Owing to the unique time-frequency properties of chirped waveforms, OCDM outperforms OFDM and single-carrier systems, and is more resilient against the noise effect, especially, when time-domain and frequency-domain distortions are severe. Experiments were carried out to validate the feasibility and advantages of the proposed OCDM systems.en
dc.description.sponsorshipScience Foundation Ireland (Grant 11/SIRG/I2124)en
dc.description.statusNot peer revieweden
dc.description.versionAccepted Version
dc.identifier.citationOuyang, X. 2017. Digital signal processing for fiber-optic communication systems. PhD Thesis, University College Cork.en
dc.publisherUniversity College Corken
dc.rights© 2017, Xing Ouyang.en
dc.subjectDigital signal processingen
dc.subjectFiber-optic communicationen
dc.subjectOrthogonal chirp division multiplexingen
dc.subjectOrthogonal frequency division multiplexingen
dc.subjectDiscrete cosine transformen
dc.subjectDiscrete fourier transformen
dc.subjectDiscrete fresnel transformen
dc.subjectFresnel integral transformationen
dc.subjectTalbot effecten
dc.subjectDispersion compensationen
dc.subjectChirp spread spectrumen
dc.subjectNyquist signaling rateen
dc.subjectNyquist waveformen
dc.titleDigital signal processing for fiber-optic communication systemsen
dc.typeDoctoral thesisen
dc.type.qualificationnamePHD (Engineering)en
Original bundle
Now showing 1 - 2 of 2
Thumbnail Image
Xing - Abstract - Thesis_Digital Signal Processing.pdf
136.24 KB
Adobe Portable Document Format
Thumbnail Image
Xing - Thesis_Digital Signal Processing.pdf
11.23 MB
Adobe Portable Document Format
Full Text E-Thesis
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
5.62 KB
Item-specific license agreed upon to submission