Rotation-based unitary transformations have gained remarkable interest due to such excellent features as parameterization, fast algorithms and generalization of other transforms. These properties make them applicable for multicarrier modulation and demodulation in communication systems. Utilization of this new class of transforms for multicarrier modulation allows creating parametric systems with dynamically adjustable subcarrier waveforms. The proposed approach requires the design of new and the adaptation of existing channel estimation, equalization and synchronization algorithms. One of the major objectives of this book is the analysis and development of building blocks for generalized unitary rotation -based multicarrier systems. Book contains a complete example of parametric multicarrier system, which includes a selection of the proposed methods. New signal processing structures and communication system configurations described in this book will be especially useful to scientists and engineers dealing with cutting edge physical layer designs for digital communications.