Unitary design of radar waveform diversity sets (original) (raw)
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Waveform Design For MIMO Radar Systems
Iconic Research and Engineering Journals, 2020
Waveform design is critical to the realization of a Multiple Input Multiple Output (MIMO) radar system. If the wave forms being transmitted are perfectly orthogonal, the virtual array consists of more elements than the transmit array and this provides additional degrees of freedom which improves performance. The correlation properties of the wave forms transmitted determine the characteristics of the system. In this paper, a binary orthogonal waveform with low auto correlation and cross correlation properties is designed. Orthogonality in transmitted wave forms is required in MIMO radar systems to enable the use of match filtering at the outputs to separate the different transmit paths. Exploiting the orthogonality of the walsh hadamard matrix based on non identical walsh functions, the simulated annealing statistical optimization tool is used to obtain the orthogonal signal set with the desired low correlation properties.
Waveform Diversity in Radar Signal Processing
IEEE Signal Processing Magazine, 2000
he advent of phased array radars and space-time adaptive processing has given radar designers the ability make radars adaptable on receive. The current state of radar technology allows the transmission of wavefields that vary across space, time, and frequency and that can be changed in rapid succession. The ability to exploit space-time adaptive processing is limited by the computational power available at the receiver, and increased flexibility on transmission only exacerbates this problem unless the waveforms are properly designed to simplify processing at the receiver. Sixty years ago, efforts by Marcel Golay to improve the sensitivity of far infrared spectrometry led to the discovery of pairs of complementary sequences. Shortly thereafter, Welti proposed to use Golay sequences in radar, but they have found very limited application to date. This article shows that suitably
2016 24th European Signal Processing Conference (EUSIPCO), 2016
We develop a new efficient method for designing unimodular waveforms with good auto-and cross-correlation properties for multiple-input multiple-output (MIMO) radar. Our waveform design scheme is conducted based on minimization of the integrated sidelobe level of designed waveforms, which is formulated as a quartic non-convex optimization problem. We start from simplifying the quartic optimization problem and then transform it into a quadratic form. By means of the majorizationminimization technique that seeks to find the solution of a corresponding quadratic optimization problem, we resolve the design of waveforms for MIMO radar. Corresponding algorithms that enable good correlations of the designed waveforms and meanwhile show faster convergence as compared to their counterparts are proposed and then tested.
Diversity in Radar Sensor Networks: Theoretical Analysis and Application to Target Detection
International Journal of Wireless Information Networks, 2009
We study a diversity scheme based on waveform design and space-time adaptive processing to improve the detection performance of radar sensor networks in the presence of certain types of interference. To reduce the interference between radar sensors and maximize the signalto-interference-plus-noise ratio, we use an orthogonality criterion to design waveforms for radar sensors. Besides, performance of radar sensor networks depends largely on clutter which is extended in both angle and range and is spread in Doppler frequency. By using the space-time adaptive processing, effects of clutter can be suppressed. We also propose a receiver for diversity combining and, as an application example, we investigate the detection performance of radar sensor networks using the proposed diversity scheme. Simulation results for both non-fluctuating targets and fluctuating targets show that the performance of the proposed scheme is superior to that of the single radar with the spatial-temporal diversity only.
Waveform Design for Joint Radar-Communications with Low Complexity Analog Components
2022 2nd IEEE International Symposium on Joint Communications & Sensing (JC&S), 2022
In this paper, we aim to design an efficient and low hardware complexity based dual-function multiple-input multiple-output (MIMO) joint radar-communication (JRC) system. It is implemented via a low complexity analog architecture, constituted by a phase shifting network and variable gain amplifier. The proposed system exploits the multiple antenna transmitter for the simultaneous communication with multiple downlink users and radar target detection. The transmit waveform of the proposed JRC system is designed to minimize the downlink multiuser interference such that the desired radar beampattern is achieved and the architecture specific constraints are satisfied. The resulting optimization problem is non-convex and in general difficult to solve. We propose an efficient algorithmic solution based on the primal-dual framework. The numerical results show enhanced performance of the proposed approach when compared to existing state-of-the-art fully-digital method. Index Terms-Joint radar-communications, MIMO, low hardware complexity, waveform design, phase shifter, primal-dual.
Entropy
In this paper, the problem of low probability of intercept (LPI)-based radar waveform design for distributed multiple-radar system (DMRS) is studied, which consists of multiple radars coexisting with a wireless communication system in the same frequency band. The primary objective of the multiple-radar system is to minimize the total transmitted energy by optimizing the transmission waveform of each radar with the communication signals acting as interference to the radar system, while meeting a desired target detection/characterization performance. Firstly, signal-to-clutter-plus-noise ratio (SCNR) and mutual information (MI) are used as the practical metrics to evaluate target detection and characterization performance, respectively. Then, the SCNR-and MI-based optimal radar waveform optimization methods are formulated. The resulting waveform optimization problems are solved through the well-known bisection search technique. Simulation results demonstrate utilizing various examples and scenarios that the proposed radar waveform design schemes can evidently improve the LPI performance of DMRS without interfering with friendly communications.
Waveform interference mitigation for a shared spectrum MIMO radar system
2010
MIMO radars may outperform conventional ones as regards target detection, parameter estimation and classification via spatial and waveform diversities. MIMO radar is a kind of shared spectrum system: the mutual interference among the waveforms may lead to considerable performance degradation, especially with multiple targets. As a result, preserving MIMO radar performance under such conditions via waveform design becomes an interesting research topic. In this paper, we consider the marriage of space time coding (STC) and Golay complementary pairs to mitigate both waveform autocorrelation and crosscorrelation effects, and hence to enhance range resolution. The implementation is discussed, and an application for instantaneous polarization is briefly introduced.
Overlapped-MIMO radar waveform design for coexistence with communication systems
2015 IEEE Wireless Communications and Networking Conference (WCNC), 2015
This paper explores an overlapped-multiple-input multiple-output (MIMO) antenna architecture and a spectrum sharing algorithm via null space projection (NSP) for radarcommunications coexistence. In the overlapped-MIMO architecture, the transmit array of a collocated MIMO radar is partitioned into a number of subarrays that are allowed to overlap. Each of the antenna elements in these subarrays have signals orthogonal to each other and to the elements of the other subarrays. The proposed architecture not only improves sidelobe suppression to reduce interference to communications system, but also enjoys the advantages of MIMO radar without sacrificing the main desirable characteristics. The radar-centric spectrum sharing algorithm then projects the radar signal onto the null space of the communications system's interference channel, which helps to avoid interference from the radar. Numerical results are presented which show the performance of the proposed waveform design algorithm in terms of overall beampattern and sidelobe levels of the radar waveform and finally shows a comparison of the proposed system with existing collocated MIMO radar architectures.
Waveform Design and Related Processing for Multiple Target Detection and Resolution
Topics in Radar Signal Processing, 2018
The performance of modern radar systems mostly depends on the radiated waveforms, whose design is the basis of the entire system design. Today's coherent, solidstate radars (either of the phased array type or of the single-radiator type as air traffic control or marine radars) transmit a set of deterministic signals with relatively large duty cycles, an order of 10%, calling for pulse compression to get the required range resolution. Often, power budget calls for different pulse lengths (e.g., short, medium, and long waveforms with a rectangular envelope) to cover the whole radar range. The first part of the chapter includes the topic of mitigating the effect of unwanted side lobes, inherent to every pulse compression, which is achieved both by a careful and optimal design of the waveform and by a (possibly mismatched) suitable processing. The second part of the chapter deals with the novel noise radar technology, not yet used in commercial radar sets but promising: (1) to prevent radar interception and exploitation by an enemy part and (2) to limit the mutual interferences of nearby radars, as in the marine environment. In this case, the design includes a tailoring of a set of pseudo-random waveforms, generally by recursive processing, to comply with the system requirements.
Adaptive Radar Waveform Design for Multiple Targets: Computational Aspects
2007
In this paper we describe the optimization of an information theoretic criterion for radar waveform design. The method is used to design radar waveforms suitable for simultaneously estimating and tracking parameters of multiple targets. Our approach generalizes the information theoretic water-lling approach of Bell. The paper has two main contributions. First, a new information theoretic design criterion for designing multiple waveforms under a joint power constraint when beamforming is used both at transmitter and receiver. Then we provide a highly ef cient algorithm for optimizing the transmitted waveforms, by approximating the information theoretic cost function. We show that using Lagrange relaxation the optimization problem can be decoupled into a parallel set of lowdimensional search problems at each frequency, with dimension de ned by the number of targets instead of the number of frequency bands used.