Optimum Finite Duration Nyquist Signals

Halpern, P.

doi:10.1109/tcom.1979.1094486

Cited by 34 publications

(17 citation statements)

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“…Halpern [7] proposed a design for finite duration Nyquist pulses for mean power constrained channels but not subject to amplitude constraints. Considerable information on optical intensity channels and their numerous advantages have been investigated [3,8,9].…”

Section: Introductionmentioning

confidence: 99%

“…Steve [1] proposed Prolate Spheroidal Wave pulse to be used since it is time limited and also has better spectral concentration among all time limited signals. For signals limited to a single symbol interval PSWF is the optimum signal choice [7,11,12]. From studies on pulse shaping techniques for time limited systems [13,14,15] Prolate Spheroidal Wave Functions (PSWF) and Modified Hermite Polynomial Function (MHPF) have emerged as potential pulse shaping functions as they provide the optimal spectral concentration.…”

Section: Introductionmentioning

confidence: 99%

“…Individual discussion on these two contender pulses is widely available but no comparison between the two has been drawn. Design of a root Nyquist pulse which maximizes the in-band fractional energy has been proposed in [4,7], in context of electrical domain. A linear combination of PSWF pulses proposed in [4] seeks to maximize the in-band fractional energy and to satisfy the Nyquist criteria.…”

Section: Introductionmentioning

confidence: 99%

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Bandwidth Efﬁcient Root Nyquist Pulses for Optical Intensity Channels

Fatima¹,

Muhammad²,

Raza³

2015

RADIOENGINEERING

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Abstract. Indoor diffuse optical intensity channels are bandwidth constrained due to the multiple reflected paths between the transmitter and the receiver which cause considerable inter-symbol interference (ISI). The transmitted signal amplitude is inherently non-negative, being a light intensity signal. All optical intensity root Nyquist pulses are timelimited to a single symbol interval which eliminates the possibility of finding bandlimited root Nyquist pulses. However, potential exists to design bandwidth efficient pulses. This paper investigates the modified hermite polynomial functions and prolate spheroidal wave functions as candidate waveforms for designing spectrally efficient optical pulses. These functions yield orthogonal pulses which have constant pulse duration irrespective of the order of the function, making them ideal for designing an ISI free pulse. Simulation results comparing the two pulses and challenges pertaining to their design and implementation are discussed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bandwidth Efﬁcient Root Nyquist Pulses for Optical Intensity Channels

Fatima¹,

Muhammad²,

Raza³

2015

RADIOENGINEERING

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“…Halpern [3] considered single carrier linear modulation based on finite duration pulses, and found pulses that minimize the fractional out of band energy (FOBE) outside of a certain bandwidth. In [4] optimal pulses for multicarrier (OFDM) setups are derived, again with the FOBE constraint.…”

Section: Introductionmentioning

confidence: 99%

“…In [7], a more general problem is considered: what is the least bandwidth needed in order to support K orthogonal signals of finite time duration; several different bandwidth measures are used. The outcome of [3]- [5] can theoretically never be any better than [7], because particular system models are assumed. But from a practical point of view, OFDM systems are frequently used and it is intresting to investigate their ultimate performance.…”

Section: Introductionmentioning

confidence: 99%

Optimal Time-Frequency Occupancy of Finite Packet OFDM

Kapetanović

Rusek

2007

2007 IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications

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Abstract-In this paper we consider the least timefrequency product necessary to transmit a small finite symbol packet such that the symbols can be independently detected. The system model assumed is offset QAM-OFDM, based on a finite duration pulse shape. The outcome is that the optimal pulse shape is of very short duration and that the optimal symbol allocation strategy is often to use as many subcarriers as there are symbols to transmit. Symbol packets up to 150 symbols are considered.

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A design method for cascade form digital nyquist filters with zero intersymbol interference

Nakayama

1985

Electron. Comm. Jpn. Pt. I

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In data communication systems, a Nyquist waveform shaping filter is an important element. The Nyquist filter not only restricts the bandwidth of the data signal, but also realizes zero intersymbol interference where the time response intersects zero at equal intervals except at one point. This paper discusses a design method of a digital Nyquist waveform shaping filter for sampled signals. In particular, the method proposes realization of overall zero intersymbol interference when an identical transfer function is used for both the transmitter and receiver filters. In this method, the transfer function coefficients are used as approximate variables. They are divided into coefficient xf for time response approximation and xf that approximates the frequency response. The condition for zero intersymbol interference is given as the linear equation for xt. Therefore, the approximation variable xt for realization of zero intersymbol interference is obtained from solution of the linear equation. On the other hand, the frequency response is optimized with the iterative approximation due to the observation that the relation between xf and the approximation function is nonlinear. The proposed method is applicable to both the FIR filter and the IIR filter for which the conventional method is not applicable. Further, the effect of the quantization errors in the multiplier coefficients and in the internal signal on the intersymbol interference is analyzed, and an estimation formula is obtained.

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Optimum Finite Duration Nyquist Signals

Cited by 34 publications

References 1 publication

Bandwidth Efﬁcient Root Nyquist Pulses for Optical Intensity Channels

Bandwidth Efﬁcient Root Nyquist Pulses for Optical Intensity Channels

Optimal Time-Frequency Occupancy of Finite Packet OFDM

A design method for cascade form digital nyquist filters with zero intersymbol interference

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