Scale based coding of digital communication signals

Multiple-access communication schemes using wavelet-based orthogonal codes are described. In the simplest such scheme, the message bit stream in each channel is encoded as a sequence of time-shifted replicates of a mother wavelet symbol at a particular scale. Different channels use the same wavelet symbol but a different scale. The messages are decodable if the time-shifted and dilated replicates of the wavelet symbol used in the encoding are orthogonal. Variations and potential applications of this scale-division multiple-access scheme in low-probability-of-exploitation communication systems are discussed. Examples are presented to demonstrate the (Fourier) spectral spreading that can be obtained using this approach