Coherent Train of Diverse Pulses

The chapter describes methods for pulse to pulse diversity. The methods described are used for reduction in the height of the recurrent (range) lobes of the autocorrelation function (ACF), reduction of the near range sidelobes (namely around the mainlobe) and for increasing the overall bandwidth of the signal, while maintaining relatively narrow instantaneous bandwidth.

The signals described include:

• Phase coded pulse train - used to lower range recurrent lobes.

• Stepped-frequency signal ��-�� used for increasing bandwidth. The chapter also describes a simple processor that is often used with it - the stretch-processor. The specific case of a stepped frequency LFM pulse train is described in details together with means of nullifying ACF grating lobes and Costas ordering the pulses.

• Complementary phase coded pulse trains yield zero ACF sidelobes around the mainlobe area. Methods for generating binary and polyphase complementary codes for different lengths and set size are described. Signals based on complementary sets based on the PONS construction and orthogonal matrices are described with more details.

• Sub-complementary phase coded pulse trains.

• Orthogonal coded pulse trains, with focus on orthogonal coded LFM pulse trains, LFM-LFM pulse trains and LFM-NLFM pulse trains.