wavelet filters computed from a wavelet transform are used for encoding , transmitting , receiving , and decoding spread spectrum signals on multiple parallel frequency channels . the transmitter encodes the data stream via a mapping to a basis set of wavelets which are orthogonal across the time domain . the spread spectrum data is parsed from a serial bit stream to several parallel streams . the number of bits per symbol need not remain constant . signals are created from each symbol by first up sampling by inserting zeros between successive symbols . these signals are passed through a bank of low - pass and high - pass filters derived from a wavelet packet transform . the resulting signal is transmitted in the base band of the transmission system , or transmitted by modulating the carrier of the transmission system . at the receiver , the steps are reversed to recover the symbols . symbol decisions are made through any one of a number of methods .