Faster than Nyquist Signaling

Dasalukunte, Deepak; Öwall, Viktor; Rusek, Fredrik; Anderson, John B.

doi:10.1007/978-3-319-07031-5

Cited by 24 publications

(11 citation statements)

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“…Using the software for the oscilloscope on the computer, set the sample rate to at least 8 Hz to resolve the thrashing cycle of the worm sufficiently. NOTE: The sample rate should be more than twice that of the expected thrashing frequencies of the species so that the Nyquist theorem 11 is satisfied.…”

Section: Protocolmentioning

confidence: 99%

Fourier-Based Diffraction Analysis of Live <em>Caenorhabditis elegans</em>

Magnes

Hastings

Raley‐Susman

et al. 2017

JoVE

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This manuscript describes how to classify nematodes using temporal far-field diffraction signatures. A single C. elegans is suspended in a water column inside an optical cuvette. A 632 nm continuous wave HeNe laser is directed through the cuvette using front surface mirrors. A significant distance of at least 20-30 cm traveled after the light passes through the cuvette ensures a useful far-field (Fraunhofer) diffraction pattern. The diffraction pattern changes in real time as the nematode swims within the laser beam. The photodiode is placed off-center in the diffraction pattern. The voltage signal from the photodiode is observed in real time and recorded using a digital oscilloscope. This process is repeated for 139 wild type and 108 "roller" C. elegans. Wild type worms exhibit a rapid oscillation pattern in solution. The "roller" worms have a mutation in a key component of the cuticle that interferes with smooth locomotion. Time intervals that are not free of saturation and inactivity are discarded. It is practical to divide each average by its maximum to compare relative intensities. The signal for each worm is Fourier transformed so that the frequency pattern for each worm emerges. The signal for each type of worm is averaged. The averaged Fourier spectra for the wild type and the "roller" C. elegans are distinctly different and reveal that the dynamic worm shapes of the two different worm strains can be distinguished using Fourier analysis. The Fourier spectra of each worm strain match an approximate model using two different binary worm shapes that correspond to locomotory moments. The envelope of the averaged frequency distribution for actual and modeled worms confirms the model matches the data. This method can serve as a baseline for Fourier analysis for many microscopic species, as every microorganism will have its unique Fourier spectrum.

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Section: Protocolmentioning

confidence: 99%

Fourier-Based Diffraction Analysis of Live <em>Caenorhabditis elegans</em>

Magnes

Hastings

Raley‐Susman

et al. 2017

JoVE

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“…Thus, pulses are packed closer than the Nyquist limit without performance degradation, provided that the optimum sequence detector is employed. Analogously, a closer packing can be achieved also in frequency domain without performance degradation (two-dimensional Mazo limit) [10]- [13]. This approach, however, does not provide the best performance in terms of (2) and poses no constraints on the complexity of the required detector.…”

Section: Time-frequency Packingmentioning

confidence: 99%

Optical Time–Frequency Packing: Principles, Design, Implementation, and Experimental Demonstration

Secondini

Foggi²,

Fresi

et al. 2015

J. Lightwave Technol.

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Time-frequency packing (TFP) transmission provides the highest achievable spectral efficiency with a constrained symbol alphabet and detector complexity. In this work, the application of the TFP technique to fiber-optic systems is investigated and experimentally demonstrated. The main theoretical aspects, design guidelines, and implementation issues are discussed, focusing on those aspects which are peculiar to TFP systems. In particular, adaptive compensation of propagation impairments, matched filtering, and maximum a posteriori probability detection are obtained by a combination of a butterfly equalizer and four 8-state parallel Bahl-Cocke-Jelinek-Raviv (BCJR) detectors. A novel algorithm that ensures adaptive equalization, channel estimation, and a proper distribution of tasks between the equalizer and BCJR detectors is proposed. A set of irregular low-density parity-check codes with different rates is designed to operate at low error rates and approach the spectral efficiency limit achievable by TFP at different signal-to-noise ratios. An experimental demonstration of the designed system is finally provided with five dual-polarization QPSK-modulated optical carriers, densely packed in a 100 GHz bandwidth, employing a recirculating loop to test the performance of the system at different transmission distances.Index Terms-Time-frequency packing, faster-than-Nyquist signaling, information theory, optical fiber communication, coherent optical systems.

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“…Either coded or uncoded, FTN signalling can provide up to twice the bandwidth efficiency of ordinary modulation. The performance tests over software implementations of both baseband and carrier system are depicted in [8].…”

Section: Introductionmentioning

confidence: 99%

“…For FTN signalling [7], [8], typical T-orthogonal pulses such as unit-T Sinc pulses are used. The technique can pack 30% ∼ 100% more data in the same bandwidth at the same 978-1-4799-8078-9/15/$31.00 ©2015 IEEE 22nd International Conference on Telecommunications (ICT 2015) energy per bit and error rate compared with traditional linear methods.…”

Section: Introductionmentioning

confidence: 99%

Performance analysis of A NOWT scheme for high spectral efficiency communications

Wang

Zhou

et al. 2015

2015 22nd International Conference on Telecommunications (ICT)

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Performance analysis of a bandlimited nonorthogonal waveform transmission (NOWT) scheme for high data rate wireless communications is presented. The technique is a potential alternative to classic orthogonal multiplexing techniques such as OFDM and QAM. It shows faster data transmission rate than Nyquist rate, and considerable performance gain compared with orthogonal techniques, as well as much lower peak to average power ratio (PAPR). The error probability in AWGN channel is derived, and the free squared Euclidean distance of NOWT signal is no more than the minimum squared distance of its modulation constellation. Analysis and numerical results demonstrate that the bandwidth efficiency and capacity of coded/uncoded NOWT technique is higher than Nyquist signalling and orthogonal techniques.

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Faster than Nyquist Signaling

Cited by 24 publications

References 0 publications

Fourier-Based Diffraction Analysis of Live <em>Caenorhabditis elegans</em>

Fourier-Based Diffraction Analysis of Live <em>Caenorhabditis elegans</em>

Optical Time–Frequency Packing: Principles, Design, Implementation, and Experimental Demonstration

Performance analysis of A NOWT scheme for high spectral efficiency communications

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