title: Spectrum shaping with parity sequences.
abstract: For certain types of digitally generated holographic memories, it is important that the Fourier components to be stored have a constant, or nearly constant, modulus. It is shown that by interlacing two sequences of complex numbers, one a data sequence representing the information to be stored and the second a parity sequence, derivable from the data sequence, the discrete Fourier transform of the combined sequence can be made to have a constant modulus. A slight variation of the method leads to a spectrum with varying modulus but only a discrete set of phases. The sequences may be one-dimensional or multidimensional.
authors.forename: D C
authors.initials: DC
authors.lastname: Chu
authors.forename: J W
authors.initials: JW
authors.lastname: Goodman