Image Transmission via Spread Spectrum Techniques. Part B
Abstract
The chirp z-transform (CZT) algorithm for performing spectral analysis is ideally suited to charge transfer technology because in the CZT, most of the computation is sampled-data convolution. The possibility of using charge transfer devices (CTDs) to implement the CZT was first discussed by Whitehouse, Speiser, and Means, and the concept was first demonstrated by Means, Buss, and Whitehouse. The goal of this research is to develop CTDs suitable for taking the cosine transform of video images using the CZT. The objective is video bandwidth reduction by cosine transform encoding. CTDs fall into two categories: bucket brigade devices (BBDs) and the better-known charge coupled devices (CCDs). Of the two, CCDs can be operated at higher frequency and are the ultimate choice for the present video bandwidth reduction application. However, at the beginning of the research a BBD filter design existed that could be quickly and cheaply recoded for the cosine transform application. Consequently, the program was divided into two parts: (1) an initial phase to produce 199- stage BBDs, and (2) a final phase to develop 63-stage CCD filters together with the electronics required to perform the cosine transform. Those two phases are discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1976
- Accession Number
- ADA103413