With coherent mixing in the optical domain and processing in the digital domain, advanced receiving techniques employing ultra-high speed sampling rates have progressed tremendously over the last few years. These advances have brought coherent reception systems for lightwave-carried information to the next stage, resulting in ultra-high capacity global internetworking. Digital Processing: Optical Transmission and Coherent Receiving Techniques describes modern coherent receiving techniques for optical transmission and aspects of modern digital optical communications in the most basic lines. The book includes simplified descriptions of modulation techniques for such digital transmission systems carried by light waves. It discusses the basic aspects of modern digital optical communications in the most basic lines. In addition, the book covers digital processing techniques and basic algorithms to compensate for impairments and carrier recovery, as well as noise models, analysis, and transmission system performance.