251. Low Correlation Interference OFDM-NLFM Waveform Design for MIMO Radar Based on Alternating Optimization
- Author
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Tianqu Liu, Guohua Wang, Qing Li, Jinping Sun, Zhimei Hao, Liu, Tianqu [0000-0003-1199-1279], Sun, Jinping [0000-0002-7184-5057], and Apollo - University of Cambridge Repository
- Subjects
MIMO radar ,Computer science ,Orthogonal frequency-division multiplexing ,TP1-1185 ,Biochemistry ,Signal ,Article ,alternating optimization ,Analytical Chemistry ,block coordinate descent (BCD) ,Chirp ,Waveform ,ComputerSystemsOrganization_SPECIAL-PURPOSEANDAPPLICATION-BASEDSYSTEMS ,Electrical and Electronic Engineering ,Coordinate descent ,Instrumentation ,OFDM ,particle swarm optimization (PSO) ,sub-chirp rate ,Cross-correlation ,Chemical technology ,Particle swarm optimization ,cross-correlation function ,Atomic and Molecular Physics, and Optics ,auto-correlation function sidelobe ,NLFM ,Frequency modulation ,Algorithm - Abstract
The OFDM chirp signal is suitable for MIMO radar applications due to its large time-bandwidth product, constant time-domain, and almost constant frequency-domain modulus. Particularly, by introducing the time-frequency structure of the non-linear frequency modulation (NLFM) signal into the design of an OFDM chirp waveform, a new OFDM-NLFM waveform with low peak auto-correlation sidelobe ratio (PASR) and peak cross-correlation ratio (PCCR) is obtained. IN-OFDM is the OFDM-NLFM waveform set currently with the lowest PASR and PCCR. Here we construct the optimization model of the OFDM-NLFM waveform set with the objective function being the maximum of the PASR and PCCR. Further, this paper proposes an OFDM-NLFM waveform set design algorithm inspired by alternating optimization. We implement the proposed algorithm by the alternate execution of two sub-algorithms. First, we keep both the sub-chirp sequence code matrix and sub-chirp rate plus and minus (PM) code matrix unchanged and use the particle swarm optimization (PSO) algorithm to obtain the optimal parameters of the NLFM signal’s time-frequency structure (NLFM parameters). Next, we keep current optimal NLFM parameters unchanged, and optimize the sub-chirp sequence code matrix and sub-chirp rate PM code matrix using the block coordinate descent (BCD) algorithm. The above two sub-algorithms are alternately executed until the objective function converges to the optimal solution. The results show that the PASR and PCCR of the obtained OFDM-NLFM waveform set are about 5 dB lower than that of the IN-OFDM.
- Published
- 2022
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