Simple coincidence system for side-lobe ambiguity reduction in discrete-coded waveforms

The side-lobe behaviour of the autocorrelation functions of phase-coded waveforms limits the application of these signals to the cases where a large dynamic range is not required. The simple coincidence system described in this letter allows an effective control of the side-lobe ambiguity in a large class of phase-coded signals, since the side-lobe level is maintained below a fixed value which does not depend on the signal energy, but merely on the noise power. This method can be of interest in group synchronisation of binary digital systems and, in particular, radar applications, where dense targets are not expected and an automatic counting of the targets has to be performed. A radar-detection problem where this method has been successfully utilised is mentioned.