Abstract: This work concerns physical layer collision recovery for cheap sensors with allowed var... more Abstract: This work concerns physical layer collision recovery for cheap sensors with allowed variations in frequency and delay of their communications. The work is presented as a generic, communication theoretic framework and demonstrated using UHF RFID tag technology. Previous work in this area has not provided recovery for more than two tags, which is shown to be possible in this work. Also presented is a novel mathematical model of the tag signal, incorporating the allowed variations in frequency and delay. The main ...
2008 16th European Signal Processing Conference, 2008
This paper presents a fast implementation of the MUltiple SIgnal Classification (MUSIC) estimatio... more This paper presents a fast implementation of the MUltiple SIgnal Classification (MUSIC) estimation criterion for fundamental frequency estimation of harmonic signals with known or unknown model orders. First, we reformulate the MUSIC estimator such that the MUSIC estimate can be computed directly from the signal subspace or just an arbitrary basis thereof. We also discuss the selection of a subspace tracker based on the known or unknown rank of the signal and noise subspaces. Second, we introduce an implementation of the MUSIC estimator that only involves one FFT for known model orders, and we extend it to the case of unknown model orders. The performance gain in terms of computation times obtained by the efficient implementation is significant which is demonstrated through simulations.
2012 Proceedings of the 20th European Signal Processing Conference (EUSIPCO), 2012
We show that to lower the sampling rate in a spread spectrum communication system using Direct Se... more We show that to lower the sampling rate in a spread spectrum communication system using Direct Sequence Spread Spectrum (DSSS), compressive signal processing can be applied to demodulate the received signal. This may lead to a decrease in the power consumption or the manufacturing price of wireless receivers using spread spectrum technology. The main novelty of this paper is the discovery that in spread spectrum systems it is possible to apply compressive sensing with a much simpler hardware architecture than in other systems, making the implementation both simpler and more energy efficient. Our theoretical work is exemplified with a numerical experiment using the IEEE 802.15.4 standard's 2.4 GHz band specification. The numerical results support our theoretical findings and indicate that compressive sensing may be used successfully in spread spectrum communication systems. The results obtained here may also be applicable in other spread spectrum technologies, such as Code Divisi...
Abstract: This work concerns physical layer collision recovery for cheap sensors with allowed var... more Abstract: This work concerns physical layer collision recovery for cheap sensors with allowed variations in frequency and delay of their communications. The work is presented as a generic, communication theoretic framework and demonstrated using UHF RFID tag technology. Previous work in this area has not provided recovery for more than two tags, which is shown to be possible in this work. Also presented is a novel mathematical model of the tag signal, incorporating the allowed variations in frequency and delay. The main ...
2008 16th European Signal Processing Conference, 2008
This paper presents a fast implementation of the MUltiple SIgnal Classification (MUSIC) estimatio... more This paper presents a fast implementation of the MUltiple SIgnal Classification (MUSIC) estimation criterion for fundamental frequency estimation of harmonic signals with known or unknown model orders. First, we reformulate the MUSIC estimator such that the MUSIC estimate can be computed directly from the signal subspace or just an arbitrary basis thereof. We also discuss the selection of a subspace tracker based on the known or unknown rank of the signal and noise subspaces. Second, we introduce an implementation of the MUSIC estimator that only involves one FFT for known model orders, and we extend it to the case of unknown model orders. The performance gain in terms of computation times obtained by the efficient implementation is significant which is demonstrated through simulations.
2012 Proceedings of the 20th European Signal Processing Conference (EUSIPCO), 2012
We show that to lower the sampling rate in a spread spectrum communication system using Direct Se... more We show that to lower the sampling rate in a spread spectrum communication system using Direct Sequence Spread Spectrum (DSSS), compressive signal processing can be applied to demodulate the received signal. This may lead to a decrease in the power consumption or the manufacturing price of wireless receivers using spread spectrum technology. The main novelty of this paper is the discovery that in spread spectrum systems it is possible to apply compressive sensing with a much simpler hardware architecture than in other systems, making the implementation both simpler and more energy efficient. Our theoretical work is exemplified with a numerical experiment using the IEEE 802.15.4 standard's 2.4 GHz band specification. The numerical results support our theoretical findings and indicate that compressive sensing may be used successfully in spread spectrum communication systems. The results obtained here may also be applicable in other spread spectrum technologies, such as Code Divisi...
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Papers by Torben Larsen