Generalized OFDM-LFM waveform design and analysis for multistatic airborne radar
01 Oct 2015-pp 924-929
TL;DR: In this paper, an orthogonal frequency division multiplexing waveform (OFDM) with linear frequency modulated (LFM) signal is designed which has a high time-bandwidth product.
Abstract: In recent years, multistatic radar systems are extensively used for detection process, as it includes multiple transmitters and multiple receivers spaced at different locations. Due to multiple transmitted signals by multiple transmitters, waveform design with a large time-bandwidth product, low cross-correlation interferences, and a low peak-average power ratio, is a challenging task. Even though many waveform design techniques exist, they lack high time-bandwidth product, which is one of the primary requirements for multistatic airborne radars. In this paper to meet these requirements, in the present study an orthogonal frequency division multiplexing waveform (OFDM) with linear frequency modulated (LFM) signal is designed which has a high time-bandwidth product. This method jointly utilizes the effectiveness of conventional LFM and OFDM signals, to achieve spectral efficiency through multi carrier modulation as well as better range and Doppler resolution. A generalized formulation of OFDM-LFM waveform is presented and the performance is analyzed in time and frequency domains in terms of various ambiguity function parameters.
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TL;DR: In this paper , the authors systematically review the literature on integrated sensing and communication (ISAC) signals from the perspective of mobile communication systems, including ISAC signal design, signal processing, and signal optimization, including peak-to-average power ratio optimization, interference management, and adaptive signal optimization for ISAC signals.
Abstract: Integrated sensing and communication (ISAC) has the advantages of efficient spectrum utilization and low hardware cost. It is promising to be implemented in the fifth-generation-advanced (5G-A) and sixth-generation (6G) mobile communication systems, having the potential to be applied in intelligent applications requiring both communication and high-accurate sensing capabilities. As the fundamental technology of ISAC, ISAC signal directly impacts the performance of sensing and communication. This article systematically reviews the literature on ISAC signals from the perspective of mobile communication systems, including ISAC signal design, ISAC signal processing, and ISAC signal optimization. We first review the ISAC signal design based on 5G, 5G-A, and 6G mobile communication systems. Then, radar signal processing methods are reviewed for ISAC signals, mainly including the channel information matrix method, spectrum lines estimator method, and super-resolution method. In terms of signal optimization, we summarize peak-to-average power ratio (PAPR) optimization, interference management, and adaptive signal optimization for ISAC signals. This article may provide the guidelines for the research of ISAC signals in 5G-A and 6G mobile communication systems.
5 citations
TL;DR: In this article , the authors investigated how to apply the positioning reference signal (PRS) of the 5G mobile communications in radar sensing and derived the Crámer-Rao lower bound of the range and velocity estimation for PRS-based radar sensing.
Abstract: The emerging joint sensing and communication (JSC) technology is expected to support new applications and services, such as autonomous driving and extended reality (XR), in the future wireless communication systems. Pilot (or reference) signals in wireless communications usually have good passive detection performance, strong anti-noise capability and good auto-correlation characteristics, hence they bear the potential for applying in radar sensing. In this paper, we investigate how to apply the positioning reference signal (PRS) of the 5th generation (5G) mobile communications in radar sensing. This approach has the unique benefit of compatibility with the most advanced mobile communication system available so far. Thus, the PRS can be regarded as a sensing reference signal to simultaneously realize the functions of radar sensing, communication and positioning in a convenient manner. Firstly, we propose a PRS based radar sensing scheme and analyze its range and velocity estimation performance, based on which we propose a method that improves the accuracy of velocity estimation by using multiple frames. Furthermore, the Crámer-Rao lower bound (CRLB) of the range and velocity estimation for PRS based radar sensing and the CRLB of the range estimation for PRS based positioning are derived. Our analysis and simulation results demonstrate the feasibility and superiority of PRS over other pilot signals in radar sensing. Finally, some suggestions for the future 5G-Advanced (5G-A) and 6th generation (6G) frame structure design containing the sensing reference signal are derived based on our study.
3 citations
TL;DR: In this paper , the authors systematically review the literature on integrated sensing and communication (ISAC) signals from the perspective of mobile communication systems, including ISAC signal design, isAC signal processing algorithms and ISAC optimization.
Abstract: Integrated sensing and communication (ISAC) has the advantages of efficient spectrum utilization and low hardware cost. It is promising to be implemented in the fifth-generation-advanced (5G-A) and sixth-generation (6G) mobile communication systems, having the potential to be applied in intelligent applications requiring both communication and high-accurate sensing capabilities. As the fundamental technology of ISAC, ISAC signal directly impacts the performance of sensing and communication. This article systematically reviews the literature on ISAC signals from the perspective of mobile communication systems, including ISAC signal design, ISAC signal processing algorithms and ISAC signal optimization. We first review the ISAC signal design based on 5G, 5G-A and 6G mobile communication systems. Then, radar signal processing methods are reviewed for ISAC signals, mainly including the channel information matrix method, spectrum lines estimator method and super resolution method. In terms of signal optimization, we summarize peak-to-average power ratio (PAPR) optimization, interference management, and adaptive signal optimization for ISAC signals. This article may provide the guidelines for the research of ISAC signals in 5G-A and 6G mobile communication systems.
1 citations
TL;DR: Simulation results show that the proposed LFM-OFDM framework can not only transmit data information including communication and remote control data information, but also estimate the speed and distance of the target by its signal features.
Abstract: This paper proposes a unified system framework based on linear frequency modulation (LFM) and orthogonal frequency-division multiplexing (OFDM) as a solution for resource sharing, especially sharing space and hardware. The proposed OFDM-LFM framework can not only transmit data flow by OFDM but also make it possible to extract features from the signal by LFM. Further, the signal features are used to construct a pseudospectrum related to the target speed and distance, thereby estimating the speed and distance of the target. Unified means using signal features to estimate target speed and distance while ensuring data transmission including communication and remote control data information. Besides the traditional data transmission mode, the ability of estimating target speed and distance is an additional benefit. The proposed unified framework makes control of transmission easier and saves more hardware resources. The simulation results show that the proposed LFM-OFDM framework can not only transmit data information including communication and remote control data information, but also estimate the speed and distance of the target by its signal features.
Cites methods from "Generalized OFDM-LFM waveform desig..."
...So far, OFDM-LFM is mainly used in waveform design [5] and MIMO radar [6]....
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References
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Book•
01 Jan 1962
TL;DR: This chapter discusses Radar Equation, MTI and Pulse Doppler Radar, and Information from Radar Signals, as well as Radar Antenna, Radar Transmitters and Radar Receiver.
Abstract: 1 An Introduction to Radar 2 The Radar Equation 3 MTI and Pulse Doppler Radar 4 Tracking Radar 5 Detection of Signals in Noise 6 Information from Radar Signals 7 Radar Clutter 8 Propogation of Radar Waves 9 The Radar Antenna 10 Radar Transmitters 11 Radar Receiver
6,010 citations
"Generalized OFDM-LFM waveform desig..." refers background in this paper
...frequency with a frequency sweep rate of , then the instantaneous phase of the chirp (LFM) signal is represented as [9] 2 12 1...
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Book•
01 Jan 2000TL;DR: Written for researchers and engineers working in the field, Radar Systems Analysis and Design Using MATLAB provides fundamental radar principles, advanced topics, and rigorous but easy-to-follow mathematical derivations.
Abstract: From the Publisher:
Written for researchers and engineers working in the field, Radar Systems Analysis and Design Using MATLAB provides fundamental radar principles, advanced topics, and rigorous but easy-to-follow mathematical derivations.
875 citations
"Generalized OFDM-LFM waveform desig..." refers background or methods in this paper
...In a radar system the AF is defined by [1] 0 1 2 3 4 5 6 -1 -0....
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...These data sequences are transformed into the time domain by the 2N-point inverse discrete Fourier transform (IDFT), which is the OFDM modulation [1]....
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...The technique of applying a different chirp rate for each pulse is known as chirp diversity [1]....
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...The spectrum of a single LFM is rectangular in shape with increased time bandwidth product [1]....
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...In order to resolve this trade off, researchers had developed a technique called pulse compression by which the properties of a short duration pulse can be achieved by compressing a long duration pulse [1]....
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TL;DR: The modulation and the demodulation processing in regard to typical spaceborne SAR receive signals are introduced and verified by a simulation for the case of pointlike targets.
Abstract: In this letter, we present a new waveform technique for the use of multiple transmitters in synthetic aperture radar (SAR) data acquisition. This approach is based on the principle of the orthogonal-frequency-division-multiplexing technique. Unlike multiple subband approaches, the proposed scheme allows the generation of multiple orthogonal waveforms on common spectral support and thereby enables to exploit the full bandwidth for each waveform. This letter introduces the modulation and the demodulation processing in regard to typical spaceborne SAR receive signals. The proposed processing techniques are verified by a simulation for the case of pointlike targets.
138 citations
"Generalized OFDM-LFM waveform desig..." refers background or methods in this paper
...Sebt et al proposed an OFDM radar signal by optimizing the shape of the ambiguity function using the least square and finally an algorithm is proposed to lower the peak to average power ratio [4, 7]....
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...However, sensitivity to time and frequency synchronization is beneficial for radar systems because radar receiver usually uses a stored version of the transmitted signal to measure time-delay and frequency offset between the transmitted signal and the received signal to derive the target parameters [7]....
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...According to Parseval’s theorem [7], the total energy of the input sequence is conserved and they will occupy samefrequencybandwidth as shown in Fig....
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...Kim [7] implemented two OFDMs to modulate the same input sequence that results in two different sequences....
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...Kim in 2013 presented an OFDM based new waveform technique for the use of multiple transmitters in synthetic aperture radar (SAR) data acquisition [7]....
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04 May 2009
TL;DR: In this article, the authors describe the design and architectural composition of a radar system built on OFDM platform, where the radar signal is generated digitally by forming an arbitrary-length vector of OFDM subcarrier amplitudes and translating it in analog format via 1000 Ms/s D/A conversion.
Abstract: This paper describes the design and architectural composition of a radar system built on OFDM platform. The radar signal is generated digitally by forming an arbitrary-length vector of OFDM sub-carrier amplitudes and translating it in analog format via 1000 Ms/s D/A conversion. The resultant baseband signal has a bandwidth of 500 MHz, and variable number and composition of sub-carriers, which may be changed on a pulse-to-pulse basis. The signal is upconverted to 7.5 GHz carrier frequency and emitted via small-form horn antenna. The receiver includes 1 Gs/s A/D converter and processing is performed in frequency domain. The system is currently configured for short-range applications (3–5 m) and can be used as radar or communication unit without any changes to hardware and with very minimal changes to software. Experimental results from high-resolution range profile imaging and broadband data communications are presented and discussed.
91 citations
"Generalized OFDM-LFM waveform desig..." refers background in this paper
...But the major limitations of the LFM signal are the complexity in achieving adequate pulse-to-pulse diversity [4] and the range Doppler coupling [5]....
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...2009 in their paper described the application of wideband OFDM systems for radar systems [5]....
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TL;DR: The novel processing technique is analyzed in detail, through both analytical derivations and Monte Carlo simulations, to demonstrate the feasibility of using the OFDM modulation with random phase coding for radar signals.
Abstract: The OFDM communication signal is proposed for spread spectrum radar signal generation. A radar signal processing technique is developed to solve the Doppler ambiguity in the pulsed Doppler radar by exploiting the multicarrier structure of the OFDM and the random phase modulation on the carriers in a Doppler compensation scheme. The novel processing technique is analyzed in detail, through both analytical derivations and Monte Carlo simulations, to demonstrate the feasibility of using the OFDM modulation with random phase coding for radar signals.
75 citations
"Generalized OFDM-LFM waveform desig..." refers background in this paper
...The OFDM signals can be generated by choosing any one of the modulation scheme such as binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), or quadrature amplitude modulation (QAM) that contains a certain number of bits per symbol [10]....
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