Title :
Multiple access based on Gabor transform
Author :
Joshi, Sanjay M. ; Morris, Joel M.
Author_Institution :
Dept. of Comput. Sci. & Electr. Eng., Maryland Univ., Baltimore, MD, USA
Abstract :
An oversampled discrete-time Gabor (1946) transform (DTGT) has inherent redundancy for signal representation in the joint time-frequency domain. In the proposed multiple access communication system, this redundancy is used to separate different signals. The DTGTs of all users´ signals are transmitted in the same time slots and frequency bands. The DTGTs of the signals can be separated if the analysis windows used in their computation satisfy a pseudo-orthogonality condition defined in this paper. A limit on the number of windows that can be pseudo-orthogonal (PO) to each other is derived. Two methods of designing PO windows using pseudo-noise sequences and wavelet filters are demonstrated
Keywords :
discrete transforms; filtering theory; multi-access systems; pseudonoise codes; sequences; signal representation; signal sampling; spread spectrum communication; time-frequency analysis; wavelet transforms; PN sequences; analysis windows; frequency bands; joint time-frequency domain; multiple access communication system; oversampled discrete-time Gabor transform; pseudo-noise sequences; pseudo-orthogonality condition; redundancy; signal representation; spread spectrum communication; time slots; wavelet filters; Communication channels; Computer science; Design methodology; Discrete transforms; Filters; Signal analysis; Signal representations; Time frequency analysis; Transmitters; Wavelet domain;
Conference_Titel :
Time-Frequency and Time-Scale Analysis, 1998. Proceedings of the IEEE-SP International Symposium on
Conference_Location :
Pittsburgh, PA
Print_ISBN :
0-7803-5073-1
DOI :
10.1109/TFSA.1998.721400
