A class of pseudonoise-like pulse compression codes

The authors describe a class of pulse compression waveform designs suitable for applications requiring low peak power, large duty factors, and large compression ratios. The waveforms are closely related to those derived from pseudonoise (PN) sequences, and exhibit many of the same properties. However, they exist in code lengths for which PN sequences cannot be constructed and offer the user greater flexibility in selecting a waveform design to match specific needs. In addition, as with m-sequences, the design can be used with an offset technique that renders perfect sidelobe cancellation in the periodic cross-correlation function, without any broadening of the mainlobe peak. The method used to generate the new codes is shown, their essential mathematical properties are discussed, and a general expression for the offset values that produce zero sidelobe levels in the periodic cross-correlation function of the waveform is derived. It is proved that the sequences presented are a special case of a more general set of Legendre-like sequences, for which the cross-correlation properties are derived