This book details modern precoding techniques for modern digital communications systems. It covers both the fundamentals of the subject as well as system applications. Coverage first provides an overview of existing precoding techniques. From this tutorial overview, readers can understand the evolution of precoding and the principles of various precoding schemes. The book then discusses the application of state-of-the-art precoding schemes to current and/or emerging communication systems to combat impairments such as inter-symbol interference (ISI), multiaccess interference (MAI) and the Doppler effect. Those communication systems include: orthogonal frequency division multiplexing (OFDM), multiuser OFDM, MC-CDMA, multi-input and multi-output (MIMO) and ultra wideband (UWB) radio systems. In addition, a discussion on advanced topics and an extensive list of references will facilitate researchers to further explore this subject on their own.