Wireless mobile communications has greatly benefited from the adoption of advanced signal processing techniques and components. In particular, the advent of low-cost very large scale integrated (VLSI) chips has allowed the design and implementation of efficient communications systems based on spread-spectrum signals, namely, the different code-division multiple-access (CDMA) radio networks currently in operation or being deployed. The aim of this chapter is to provide the reader with a basic understanding of the diverse digital signal processing (DSP) algorithms that lie at the foundation of such systems. After a short introduction to wireless communications (Section 10.1), the chapter develops into a description of the basic characteristics of digital spread-spectrum signals (Section 10.2). This sets the framework for the subsequent general study of CDMA techniques (Section 10.3) and description of current standards (Section 10.4). Next, the focus is shifted to the functions of signal synchronization for optimum data detection (Section 10.5) and to the design of a digital CDMA receiver (Section 10.6), highlighting the main relevant DPS-intensive tasks. The final part of the chapter is devoted to the introduction of an advanced topic related to the detection of digital information in a CDMA signal, namely, multiuser detection (Section 10.7).