An array of sensor elements has long been an attractive solution for severe reception problems that commonly involve signal detection and estimation. The basic reason for this attractiveness is that an array offers a means of overcoming the directivity and sensitivity limitations of a single sensor, offering higher gain and narrower beamwidth than that experienced with a single element. In addition, an array has the ability to control its response based on changing conditions of the signal environment, such as direction of arrival, polarization, power level, and frequency. The advent of highly compact, inexpensive digital computers has made it possible to exploit well-known results from signal processing and control theory to provide optimization algorithms that automatically adjust the response of an adaptive array and has given rise to a new domain called 'smart arrays.' This self-adjusting capability renders the operation of such systems more flexible and reliable and (more importantly) offers improved reception performance that would be difficult to achieve in any other way. This revised edition acquaints the reader with the historical background of the field and presents important new developments that have occurred over the last quarter century that have improved the utility and applicability of this exciting field.

Chapter Contents:

• 1.1 Motivation For Using Adaptive Arrays
• 1.2 Historical Perspective
• 1.3 Principal System Elements
• 1.4 Adaptive Array Problem Statement
• 1.5 Existing Technology
• 1.6 Organization of the Book
• 1.7 Summary and Conclusions
• 1.8 Problems
• 1.9 References

Inspec keywords: electromagnetic wave polarisation; adaptive signal detection; optimisation; sensor arrays; direction-of-arrival estimation

Other keywords: signal estimation; reception problem; beamwidth; sensor element array; adaptive array; signal detection; polarization; frequency; signal processing; sensitivity limitation; direction of arrival; reception performance; smart array; power level; optimization algorithm; directivity limitation; signal environment

Subjects: Optimisation techniques; Optimisation techniques; Electromagnetic wave propagation; Signal processing theory; Sensing devices and transducers; Signal detection