OVERVIEW

The transmitter and receiver of a digital communication system are not initially synchronized in any manner, and the channel that is used to communicate may be less than ideal. The simulation of a digital communication system is often simplified by first assuming an ideal linear channel and the perfect synchronization of the carrier frequency and phase (for bandpass systems) and the symbol or bit timing (for baseband and bandpass systems). The SystemVue simulations of baseband and bandpass digital communication systems presented in Chapter 2, "Baseband Modulation and Demodulation," and Chapter 3, "Bandpass Modulation and Demodulation," have tacitly made this assumption so that only their degraded performance due to additive white Gaussian noise (AWGN) could be assessed.

Practical digital communication systems must cope with the initial lack of synchronization and must track and acquire the needed synchronization information. The communication channel can also be nonlinear and cause additional performance degradations. Synchronization information must be continuously derived from the received signal, even in the presence of both AWGN and a nonlinear communication channel. However, as presented in this chapter, investigating the effect of synchronization and a nonlinear communication channel separately in the performance of a digital communication system facilitates the analysis.

On the CD The source files for these SystemVue simulation studies in synchronization, equalization, and channel modeling are located in the Chapter 4 folder on the CD-ROM, and are identified by the figure number (such as Fig4-1.svu). Appendix A includes a complete description of the contents of the...