This monograph deals with information-theoretic methods and analysis for developing two-dimensional constrained codes and signal processing algorithms for holographic memories. Though the applications of these theoretical ideas are aimed towards holographic memories, many of the techniques presented within this monograph are applicable to broader areas in science and technology beyond data storage. The key features of this monograph include: (1) Methods for computing capacity bounds for two-dimensional runlength-constrained channels with an eye towards designing two-dimensional codes. (2) An analysis of the holographic channel capacity and space-volume multiplexing tradeoffs for different holographic recording schemes for maximizing the volumetric storage density. (3) A study of the two-dimensional pixel misregistration problem and an algorithm for signal recovery. (4) Discussion of applications in other areas of science and engineering.

The increasing demand for high density storage devices has led to innovative data recording paradigms like optical holographic memories that record and read data in a two-dimensional page-oriented manner. In order to overcome the effects of inter-symbol-interference and noise in holographic channels, sophisticated constrained modulation codes and error correction codes are needed in these systems. This dissertation deals with the information-theoretic and signal processing aspects of holographic storage. On the information-theoretic front, the capacity of two-dimensional runlength-limited channels is analyzed. The construction of two-dimensional runlength-limited codes achieving the capacity lower bounds is discussed. This is a theoretical study on one of the open problems in symbolic dynamics and mathematical physics. The analysis of achievable storage density in holographic channels is useful for building practical systems. In this work, fundamental limits for the achievable volumetric storage density in holographic channels dominated by optical scattering are analyzed for two different recording mechanisms, namely angle multiplexed holography and localized recording. Pixel misregistration is an important signal processing problem in holographic systems. In this dissertation, algorithms for compensating two-dimensional translation and rotational misalignments are discussed and analyzed for Nyquist size apertures with low fill factors. These techniques are applicable for general optical imaging systems.

With the increasing interest in holography for 3D imaging applications, there is a need to develop and use hologram compression techniques for the efficient storage and transmission of holographic data. This book gives a broad overview of the state-of-the-art techniques for the efficient compression and representation of digital holographic data, addressing both still and moving data sequences. An Introduction to the principles of digital holography A critical analysis of the techniques that have been developed Coverage of the most recent research results A summary of future research challenges

Implementing new architectures and designs for the magnetic recording read channel have been pushed to the limits of modern integrated circuit manufacturing technology. This book reviews advanced coding and signal processing techniques and architectures for magnetic recording systems. Beginning with the basic principles, it examines read/write operations, data organization, head positioning, sensing, timing recovery, data detection, and error correction. It also provides an in-depth treatment of all recording channel subsystems inside a read channel and hard disk drive controller. The final section reviews new trends in coding, particularly emerging codes for recording channels.

Digital holography and digital image processing are twins born by computer era. They share origin, theoretical base, methods and algorithms. The present book describes these common fundamentals principles, methods and algorithms including image and hologram digitization, data compression, digital transforms and efficient computational algorithms, statistical and Monte-Carlo methods, image restoration and enhancement, image reconstruction in tomography and digital holography, discrete signal resampling and image geometrical transformations, accurate measurements and reliable target localization in images, recording and reconstruction of computer generated holograms, adaptive and nonlinear filters for sensor signal perfecting and image restoration and enhancement. The book combines theory, heavily illustrated practical methods and efficient computational algorithms and is written for senior-level undergraduate and graduate students, researchers and engineers in optics, photonics, opto-electronics and electronic engineering.

In order to adapt to the ever-increasing demands of telecommunication needs, today’s network operators are implementing 100 Gb/s per dense wavelength division multiplexing (DWDM) channel transmission. At those data rates, the performance of fiberoptic communication systems is degraded significantly due to intra- and inter-channel fiber nonlinearities, polarization-mode dispersion (PMD), and chromatic dispersion. In order to deal with those channel impairments, novel advanced techniques in modulation and detection, coding and signal processing are needed. This unique book represents a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory with the fundamentals of optical communication.