ECE 5660 Spread Spectrum Communications | ECE | Virginia Tech


Course Information


Major topics include: direct sequence and frequency hopping methods, synchronization, resistance to jamming to jamming, low probability of detection, spreading codes and their generation, system performance, Rake receivers, Code Division Multiple Access, cellular CDMA applications, wireless LAN applications, as well as commercial and military applications.

Why take this course?

Spread spectrum communications is a core technology for wireless systems. Future cellular systems are virtually all being designed using spread spectrum techniques. A large number of wireless LAN products are being designed using spread spectrum. Many military systems use spread spectrum. In fact the techniques were originally a military application only. In short, wireless communication engineers will almost certainly work on spread spectrum systems during their career. Since the design methods for spread spectrum and the principles behind them are significantly different from other communication systems, it is important to devote a course to the topic. Currently, spread spectrum is treated in a sporadic fashion in a few courses. Digital communications (ECE 5654) spends two weeks on the topic. A couple of other courses give a lecture or two, but even if a student were exposed to all of them, they would not have sufficient understanding of spread spectrum.

Learning Objectives

  • Describe the types and advantages of spread spectrum modulation formats.
  • Perform analysis on the performance of spread spectrum modulation formats.
  • Describe the differences and benefits of different types of spreading codes.
  • Describe the differences between standard narrowband communication systems and spread spectrum systems.
  • Analyze the performance of spread spectrum systems in the presence of interference.
  • Analyze the performance of spread spectrum signals in the presence of multiple access interference (CDMA context).
  • Describe techniques for reducing the impact of interference on spread spectrum signals.
  • Analyze the performance of spreading code acquisition and tracking circuits.
  • Analyze the performance of multiple access techniques based on spread spectrum (i.e., CDMA).
  • Describe the major factors influencing the capacity of CDMA wireless networks.

Course Topics


Percentage of Course

Introduction to Spread Spectrum 5%
Review of Digital Communications 5%
Direct Sequence Spread Spectrum 10%
Frequency Hopping 10%
Pseudo-random sequence generation 10%
Synchronization Issues for Spread-Spectrum 10%
Performance of Direct-Sequence Spread Spectrum 10%
Performance of Frequency-Hopped Spread-Spectrum 10%
CDMA 15%
Interference Rejection for DS/SS 10%
Other Wideband Techniques 5%