On the Necessary Accuracy of Representation of Optimal Signals

Zavjalov, Sergey V.; Ovsyannikova, Anna S.

doi:10.1007/978-3-030-01168-0_14

Cited by 4 publications

(6 citation statements)

References 14 publications

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“…This requirement is met by using the optimization criterion of ensuring the specified reduction rate of out-of-band emissions level. Solutions to this problem are considered in [20] for signals with binary phase shift keying (BPSK). The natural requirement for the cross-correlation coefficient (the condition of the guaranteed level of the BER performance), the pulse duration, and signal energy represent the optimization problem constraints.…”

Section: Optimization Problem With Constraint On Paprmentioning

confidence: 99%

“…The optimization criterion of ensuring the specified reduction rate of the level of out-of-band emissions is adopted. The optimization function can be expressed as [19,20]:…”

Section: Optimization Problem With Constraint On Paprmentioning

confidence: 99%

“…The optimization problem (6) can be reduced to the problem of finding a set of coefficients that correspond to the minimum of a function of many variables [19,20]:…”

Section: Optimization Problem With Constraint On Paprmentioning

confidence: 99%

“…The value of m is determined based on the representation accuracy of sought function a(t), and it is usually between 10 and 14 [20] for FTN signals with a duration of up to T s = 16-32 T.…”

Section: Optimization Problem With Constraint On Paprmentioning

confidence: 99%

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A Reduction of Peak-to-Average Power Ratio Based Faster-Than-Nyquist Quadrature Signals for Satellite Communication

et al. 2021

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The increase in the throughput of digital television and radio broadcasting (DVB) channels can be achieved due to application of signals with a compact spectrum and a relatively small peak-to-average power ratio (PAPR). The reason is the usage of traveling wave tubes (TWT) for amplifying and transmitting signals from a satellite repeater in DVB-S2X systems. At the same time, given that the bandwidth allocated for transmission should be used as efficiently as possible, a high reduction rate of out-of-band emissions level is required. The most effective solution in this direction is the transition to spectrum-economic signals, such as optimal Faster-Than-Nyquist (FTN) signals, which can provide a certain reduction rate of the out-of-band emissions level and minimum acceptable PAPR. This article proposes a method for obtaining optimal FTN pulses, which have symmetry in time domain, with specified PAPR and reduction rate of out-of-band emissions for the quadrature phase shift keying (QPSK) and offset quadrature phase shift keying (OQPSK). The possibility of synthesizing signals with OQPSK modulation is presented theoretically for the first time. Optimal FTN signals can provide PAPR reduction by at most 3 dB and outperform known root raised cosine (RRC) pulses. The simulation model adopts an architecture for quadrature generation of optimal FTN signals with OQPSK modulation with blocks for adjustable pre-amplification, clipping, and power amplification. The proposed signals can be used to increase the spectral and energy efficiencies of satellite broadcasting systems, such as DVB-S2/S2X, as well as low-rate return channels of interactive broadcasting systems with a frequency resource shortage.

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Section: Optimization Problem With Constraint On Paprmentioning

confidence: 99%

“…The optimization criterion of ensuring the specified reduction rate of the level of out-of-band emissions is adopted. The optimization function can be expressed as [19,20]:…”

Section: Optimization Problem With Constraint On Paprmentioning

confidence: 99%

“…The optimization problem (6) can be reduced to the problem of finding a set of coefficients that correspond to the minimum of a function of many variables [19,20]:…”

Section: Optimization Problem With Constraint On Paprmentioning

confidence: 99%

“…The value of m is determined based on the representation accuracy of sought function a(t), and it is usually between 10 and 14 [20] for FTN signals with a duration of up to T s = 16-32 T.…”

Section: Optimization Problem With Constraint On Paprmentioning

confidence: 99%

See 2 more Smart Citations

A Reduction of Peak-to-Average Power Ratio Based Faster-Than-Nyquist Quadrature Signals for Satellite Communication

et al. 2021

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“…The number of coefficients m in Fourier series is defined by the solving accuracy of the optimization problem. Generally, m is in a range from 10 to 20 [30].…”

Section: Ftn Signal Optimization By Conforming Criterion Of Maximmentioning

confidence: 99%

Optimizing the Shape of Faster-Than-Nyquist (FTN) Signals With the Constraint on Energy Concentration in the Occupied Frequency Bandwidth

et al. 2020

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The achievement of the boundary values of spectral efficiency is associated with the development of methods for generating and receiving signals with a compact spectrum. The reason is a constant increase in the capacity of existing communication channels caused by an increase in the volume of transmitted information. Moreover, the allocated frequency bandwidths have natural limitations, and they are almost all reached. The effective way to approach the boundary values of spectral efficiency is the application of spectrally efficient signals, such as FTN (Faster-Than-Nyquist) signals. This article proposes to synthesize optimal FTN signals that are more compact in the spectrum than RRC (root raised cosine) pulses-based signals. The criterion of maximum energy concentration in the occupied frequency bandwidth and the constraint on the cross-correlation coefficient are used to solve the optimization problem. The contribution of this work is the optimization of FTN signal shape. The obtained optimal FTN signals provide a 24% increase in spectral efficiency compared to the RRC pulses-based signals. At the same time, the energy loss stays almost unchanged. To the best of authors' knowledge, this is the first case when the frequency bandwidth reduction is achieved at practically no energy loss. The simulation modeling in channels with additive white Gaussian noise and fading channels is done with regard to the FTN-SC-FDE (Faster-Than-Nyquist-Single Carrier system with Frequency Domain Equalization) structure. The optimal FTN signals presented in this work can be used to increase the spectral efficiency of satellite broadcasting systems, such as DVB-S2/S2X. INDEX TERMS Faster than Nyquist signaling; maximum band energy concentration criterion; optimization methods; spectral efficiency

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