Title :
Acoustoelectric convolvers for programmable matched filtering in spread-spectrum systems
Author :
Cafarella, John H. ; Brown, William M., Jr. ; Stern, Ernest ; Alusow, John A.
Author_Institution :
Massachusetts Institute of Technology, Lexington, MA
fDate :
5/1/1976 12:00:00 AM
Abstract :
Acoustoelectric convolvers for a spread-spectrum communication application age described with a 100-MHz bandwidth. The use of convolvers as programmable matched filters provides the ability to change the coding waveform from bit-to-bit, thus offering improved multipath performance, security against decoding, and protection against repeat jamming. In this paper, we describe design and performance details of a prototype convolver which processes signals of 10-µs duration with a 100-MHz bandwidth. A dynamic range of 50 dB is obtained, and error signals are 30 dB below the output signal with input signal levels of +14 dBm. A test circuit is described which creates typical spread-spectrum signals in which each bit is encoded into 512 chips and data is encoded by inverting the phase of an entire bit at a data rate of 100 kbits/s.
Keywords :
Bandwidth; Circuit testing; Communication system security; Convolvers; Decoding; Filtering; Jamming; Matched filters; Protection; Spread spectrum communication;
Journal_Title :
Proceedings of the IEEE
DOI :
10.1109/PROC.1976.10206