Time-delay alignment technique for a randomly distributed sensor array

Shen, Caiyao; Yu, Haozheng

doi:10.1049/iet-com.2010.0671

Cited by 15 publications

(8 citation statements)

References 10 publications

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“…Where ij t is real time-delay difference and ij n is estimation error caused by the noise, ij n follows the gauss distribution [8] , namely…”

Section: Signal Modelmentioning

confidence: 99%

“…In multi-antenna signal model, the ways to solve TDOA estimation become multi-channel cross-correlation method [5] , eigenvalue decomposition method [6] , redundant fusion algorithm [7], the time-delay alignment algorithm based on quasi synthesis reference (TAQSR) [8] and so on. The multi-channel cross-correlation method and eigenvalue decomposition method are restricted by the antenna formations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An Algorithm of the Time-delay Alignment Based on Iterative Estimation

Li¹,

Zhang²,

Hu³

et al. 2016

Proceedings of the 2015 4th National Conference on Electrical, Electronics and Computer Engineering

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“…Where ij t is real time-delay difference and ij n is estimation error caused by the noise, ij n follows the gauss distribution [8] , namely…”

Section: Signal Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Algorithm of the Time-delay Alignment Based on Iterative Estimation

Li¹,

Zhang²,

Hu³

et al. 2016

Proceedings of the 2015 4th National Conference on Electrical, Electronics and Computer Engineering

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“…Coherent distributed arrays (CDAs) are a particular form of distributed wireless system where individual wireless elements coordinate at the level of the radio frequency (RF) phase to enable distributed beamforming [6], [11], [12]. Coordination of separate moving nodes is a challenging problem, in which the following three fundamental coordination tasks must be accomplished: frequency synchronization to ensure all elements are operating at the same reference frequency [13]- [16]; time alignment to ensure that there is sufficient overlap of the information at the target destination [17]- [19]; and phase alignment to enable constructive interference at the target. Phase alignment presents the most challenges due to the extremely small tolerance to errors at microwave frequencies.…”

Section: Introductionmentioning

confidence: 99%

Multi-Node Open-Loop Distributed Beamforming Based on Scalable, High-Accuracy Ranging

2022

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We present a distributed antenna array supporting open-loop distributed beamforming at 1.5 GHz. Based on a scalable, high-accuracy internode ranging technique, we demonstrate open-loop beamforming experiments using three transmitting nodes. To support distributed beamforming without feedback from the destination, the relative positions of the nodes in the distributed array must be known with accuracies below λ/15 of the beamforming carrier frequency to ensure that the array maintains at least 90% coherent beamforming gain at the receive location. For operations in the microwave range, this leads to range estimation accuracies of centimeters or lower. We present a scalable, high-accuracy waveform and new approaches to refine range measurements to significantly improve the estimation accuracy. Using this waveform with a three-node array, we demonstrate high-accuracy ranging simultaneously between multiple nodes, from which phase corrections on two secondary nodes are implemented to maintain beamforming with the primary node, thereby supporting open-loop distributed beamforming. Upon movement of the nodes, the range estimation is used to dynamically update the phase correction, maintaining beamforming as the nodes move. We show the first openloop distributed beamforming at 1.5 GHz with two-node and three-node arrays, demonstrating the ability to implement and maintain phase-based beamforming without feedback from the destination.

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“…However, the benefits of distributed beamforming come at a cost, which is the sophisticated coordination requirements. To ensure coherent operation among all distributed nodes, all elements need to be frequency locked to ensure that all oscillators are operating at the same frequency [7]- [10]; time aligned to ensure proper alignment of information at destination [11]- [14]; and phase aligned in order to have coherent summation of the signals at the destination [15]- [19].…”

Section: Introductionmentioning

confidence: 99%

Adaptive Distributed Transceiver Synchronization Over a 90 Meter Microwave Wireless Link

Mghabghab¹,

Schlegel²,

Nanzer³

2020

Preprint

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We present an adaptive approach for synchronizing both the phase and frequency of radio-frequency transceivers over long-range wireless links to support distributed antenna array applications. To enable distributed beamforming between separate wireless nodes, the oscillators in the transceivers must operate at the same frequency, and their phases must be appropriately aligned to support phase-coherent beamsteering. Based on a spectrally-sparse waveform, a self-mixing circuit, and an adaptive control loop, we present a system capable of synchronizing the RF oscillators in separate transceivers over distances of nearly 100 m. The approach is based on a spectrally-sparse waveform for joint inter-node ranging and frequency transfer. A frequency reference is modulated onto one signal of a two-tone waveform transmitted by the primary node which is demodulated and used to lock the oscillator of the secondary node. The secondary node retransmits the two-tone signal which the primary node uses for a high-accuracy range measurement. From this range, the phase of the two transceivers can be aligned to support beamforming. We furthermore implemented an adaptive phase control approach to support high-accuracy phase coordination in changing environmental conditions. We demonstrate continuous high accuracy links over a 90 m distance in an outdoor environment for durations up to seven days, demonstrating sufficient phase coordination in changing weather conditions to support distributed beamforming at frequencies up to 3 GHz.

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Time-delay alignment technique for a randomly distributed sensor array

Cited by 15 publications

References 10 publications

An Algorithm of the Time-delay Alignment Based on Iterative Estimation

An Algorithm of the Time-delay Alignment Based on Iterative Estimation

Multi-Node Open-Loop Distributed Beamforming Based on Scalable, High-Accuracy Ranging

Adaptive Distributed Transceiver Synchronization Over a 90 Meter Microwave Wireless Link

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