Methods for generation of probing signals in software defined noise radar

Software Defined Noise Radar (SDNR) design requires elaboration and implementation of both digital random signal generators and efficient algorithms for digital estimation of cross-correlations in Field Programmable Gate Array (FPGA). A new method for forming of the NR transmitted signal that enables to go around the main problems of SDNR implementation. The basic idea of the method consists in utilizing both bands of the up-converted signal spectrum, bringing them as close as possible, provided filling a gap between them with local oscillator signal, which might be random as well. In the paper we describe a simple algorithm for digital random signals generation in FPGA, its brief characterization and also some results of computer simulation of noise radar signal formation using suggested approach for VCO signal modulation by random digitally generated noise waveform. In addition, FPGA based implementation of time-integrating correlator, which is suitable for SDNR design is described.