Waveform design for improved range and Doppler resolution in radar

Abstract

The choice of a suitable transmit waveform is an important problem in radar design. This is so because the waveform controls resolution and clutter performance and also bears heavily on the system cost. Theoretical studies which provide the basis for technical advances have not, so far, solved the general signal design problem. The knowledge of the properties of the pulse trains, a class of signals particularly well suited to digital processing is therefore, of increasing practical importance. This paper presents a method for generating finite length sequences that have high energy ratio and low sidelobe energy in their autocorrelation function. The multilevel sequences with spike like autocorrelation function are generated iteratively, starting with a sequence that has relatively low sidelobes in its autocorrelation function. The method can be used to generate sequences of any desired length. It is shown that energy ratio of polyphase sequences that have low sidelobe energy, is improved through the process of clipping. Such sequences then can be effectively used to improve the range and Doppler resolution of radars.