Multi-channel wavelet codec

Abstract

An apparatus and method of for using wavelets filters computed from a wavelet transform as a means of pulse shaping binary data transmitted and received over multiple parallel channels. At the transmitter: (1) the data is parsed from a serial bit stream to several parallel streams; (2) within each of the parallel bit streams symbols are formed from the bits and consist of the set {0, 1, . . . 2k−1} where k is the number of bits per symbol. The symbols may be Grey coded to decrease the probability of a bit error. (3)[a] signals are created from each symbols by, first up sampling- by inserting zeros between successive symbols; [b] these signals are passed through a bank of low-pass and high-pass filters that are derived from a wavelet packet transform (the wavelet and scaling functions, or, equivalently the low-pass and high-pass reconstruction filters). [c] The filters are paired: one high-pass with a low-pass. The ordering is alternated to preserve “natural” frequency ordering. (4) The steps 3 [a], 3[[b] and 3[c] are repeated for this set of signals until only one signal remains. The remaining signal is transmitted in the base band of the transmission system or they are transmitted by modulating the carrier of the transmission system. At the receiver; (1) Steps 1 through 3 are reversed at the receiver to recover symbols. Symbol decisions are made through any one of a number of methods, which increase the probability of a correct decision.

Dependencies are inferred from the claim text.