Fundamentals of Adaptive Noise Canceling
Abstract
The theory underlying a possible solution, via adaptive noise canceling, to the cosite interference problem encountered by co-located frequency hopping radios is presented. It is also shown how and why adaptive noise canceling can be used, via an adaptive line enhancer (ALE), to separate narrow band deterministic and wide band random signals. Analysis of both an adaptive noise canceler with a single input and an adaptive line enhancer are described in terms of the Wiener or optimal weights of a surface acoustic wave (SAW) programmable transversal filter (PTF) contained within these circuits. In an effort to explain how an adaptive noise canceler with a single input and an ALE actually work, the functional relationship, between the optimal PTF weight values (and hence the PTF frequency response) and the interfering and intended signals is developed in much more detail than is found in textbooks or review articles. Three different adaptive algorithms (Least Mean Square, Differential Steepest Descent, and Linear Random Search) for use with these adaptive filters are also described. A SAW device implementation of a PTF that could be used in building an adaptive noise canceler with single input or an ALE is described.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1991
- Accession Number
- ADA241407
Entities
People
- Stuart D. Albert