Expanding the Unambiguous Velocity Limitation of the Stepped-Carrier OFDM Radar Scheme

Schweizer, Benedikt; Schindler, Daniel; Knill, Christina; Hasch, Jürgen; Waldschmidt, Christian

doi:10.23919/eurad.2018.8546621

Cited by 13 publications

(3 citation statements)

References 7 publications

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“…However, the unambiguous velocity v ua is decreased by the factor M , but due to the typically large initial v ua of an OFDM radar, this is bearable in most cases. Alternatively, the initial full v ua can be reconstructed [11] or random frequency steps can be combined with a compressed-sensing-based range-velocity (Rv)-evaluation as proposed in [9].…”

Section: Stepped-carrier Ofdm Radar Schemementioning

confidence: 99%

An All-Digital Carrier Synthesis for Stepped OFDM Radars

Werbunat,

Schweizer,

Maier

et al. 2023

2023 IEEE/MTT-S International Microwave Symposium - IMS 2023

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OFDM-based radars offer the potential to solve inherent limitations of current modulation schemes by shifting the main effort to the digital domain. By combining an OFDM signal with a stepped carrier, the sampling rate and memory constraints, which are limiting the bandwidth and thus the range resolution of digital radars, can be overcome. However, this is at the cost of highly increased demands on carrier synthesis. This paper presents an all-digital carrier frequency synthesis that allows to realize any desired carrier frequency progression and is synchronized to a digital OFDM radar with signal generation based on a Xilinx Zynq RFSoC. Its functionality is demonstrated using a homodyne 4x4 MIMO radar at 77 GHz.

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Section: Stepped-carrier Ofdm Radar Schemementioning

confidence: 99%

An All-Digital Carrier Synthesis for Stepped OFDM Radars

Werbunat,

Schweizer,

Maier

et al. 2023

2023 IEEE/MTT-S International Microwave Symposium - IMS 2023

Self Cite

View full text Add to dashboard Cite

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“…However, overlapping subcarriers are required for phase correction, which can lead to errors, particularly in the case of a poor signal-to-noise ratio. For this reason, the method including the associated signal processing scheme was further optimized in [12] and [13] and the hardware requirements and effects were examined in [14]. The disadvantage of this method is that the time interval between successive OFDM subsymbols at the same carrier frequency increases by the number of steps.…”

Section: Introductionmentioning

confidence: 99%

Frequency comb MIMO OFDM radar demonstrator with high unambiguous velocity

Nuß

Oliveira

Zwick

2023

Int. J. Microw. Wireless Technol.

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Digital radar waveforms such as orthogonal frequency-division multiplexing (OFDM) often have the disadvantage that they require high sampling rates if fine range resolutions have to be achieved. The frequency comb OFDM radar scheme offers a possibility to overcome this drawback and to improve the range resolution without increasing the sampling rate. Simultaneously, the high unambiguous velocity, which is one of the advantages of digital radar waveforms, is retained and due to the simple generation of orthogonal transmit signals, it is well suited for multiple-input multiple-output (MIMO) applications. To prove all these features of the frequency comb OFDM radar scheme, a suitable 4 × 4 MIMO demonstrator including frequency comb generation as well as up- and downconversion with these combs has been set up. Its functionality has been validated with real measurements in an anechoic chamber in conjunction with a radar target simulator to emulate very high velocities.

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“…As OFDM requires handling, especially sampling, the full RF bandwidth in the baseband (in contrast to, e.g., FMCW radar), several techniques have been developed to avoid sampling the full channel function at once, e.g., by exploiting the properties of nonequidistant frequency combs [27] or coherently combining data obtained from transmissions with different carrier frequencies. The latter approach, called SC-OFDM, was first demonstrated by Pfeffer et al [28] and significantly improved by Schweizer et al [29], [30] with respect to the robustness and ambiguity of the coherent phase processing involved. As there is a natural correspondence between elevation and frequency sectors for the antenna elements proposed in this work, SC-OFDM and the hybrid aperture concept benefit from each other in multiple ways.…”

Section: A Introduction To Sc-ofdm Radarmentioning

confidence: 99%

Hybrid Beam-Steering OFDM-MIMO Radar: High 3-D Resolution With Reduced Channel Count

Schneider

Rösch

Tessmann

et al. 2021

IEEE Trans. Microwave Theory Techn.

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We report on the realization of a multichannel imaging radar that achieves uniform 2-D cross-range resolution by means of a linear array of a special form of leaky-wave antennas. The presented aperture concept enables a tradeoff between the available range resolution and a reduction in the number of channels required for a given angular resolution. The antenna front end is integrated within a multichannel radar based on stepped-carrier orthogonal frequency-division modulation, and the advantages and challenges specific to this combination are analyzed with respect to signal processing and a newly developed calibration routine. The system concept is fully implemented and verified in the form of a mobile demonstrator capable of soft real-time 3-D processing. By combining radio frequency (RF) components operating in the W -band (85-105 GHz) with the presented aperture, a 3-D resolution of less than 1.5 • ×1.5 • × 15 cm is demonstrated using only eight transmitters and eight receivers.

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Expanding the Unambiguous Velocity Limitation of the Stepped-Carrier OFDM Radar Scheme

Cited by 13 publications

References 7 publications

An All-Digital Carrier Synthesis for Stepped OFDM Radars

An All-Digital Carrier Synthesis for Stepped OFDM Radars

Frequency comb MIMO OFDM radar demonstrator with high unambiguous velocity

Hybrid Beam-Steering OFDM-MIMO Radar: High 3-D Resolution With Reduced Channel Count

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