Theoretical Study And Generating Circuit Design Of MIMO Radar Waveform

Modern radar system mainly uses the digital waveform synthesis method togenerate waveform, because digital signals can meet the requirements of modern radarfor frequency agility, adaptive FM, and waveform parameter agility. And in the digitalwaveform generating technology, with its many advantages, DDS has been widely usedin military and civilian fields. A variety of waveforms can be generated based on basicwaveforms generated by DDS.This paper first describes the basic theory of MIMO radar orthogonal waveformsdesign, with emphasis on the sequential quadratic programming method. Based on DDSprinciple, orthogonal multiphase code based on this algorithm can be used to generateorthogonal waveforms. The DDS principle is introduced first to generate the orthogonalwaveforms. To fulfill the requirements to the index parameters of generated waveforms,the DSP in association with the FPGA technology is used to finally achieve a low cost,high scalability and convenient waveform generator with the capability of generatingarbitrary waveforms, such as the sine wave, square wave, triangle wave, trapezoidalwave, and pulse wave. Frequency modulation and phase modulation can be achieved aswell.First, in design of hardware circuits, the Cadence software is used to design all thecircuits and to simulate partial analog circuits. Then, based on the principle and theproposed improved algorithms, the logic design is done based on the Spartan6FPGAchip, in the environment of the Xilinx ISE.Test results show that the arbitrary waveform generator can achieve a maximumfrequency resolution of30mHz, a maximum frequency output of20MHz, and amaximum frequency accuracy of about±0.1%. With a50ohm termination output load,the generated waveforms match the desired waveforms well and the expected designrequirements are satisfied, making the proposed method of practical interest.