SMPPM a Modified Optical Wireless Multi-pulse PPM

2020 ◽  
Vol 41 (2) ◽  
pp. 181-184
Author(s):  
Mehdi Rouissat ◽  
Ahmed R. Borsali
Keyword(s):  
Spectral Efficiency ◽  
Power Efficiency ◽  
Optical Systems ◽  
Modulation Scheme ◽  
Bandwidth Efficiency ◽  
Optical Wireless ◽  
Symbol Synchronization ◽  
Synchronization Problem ◽  
Important Improvement ◽  
Moderate Power

AbstractSynchronized multi-pulse PPM “SMPPM” is a new proposed modulation scheme based on MPPM proposed for wireless optical systems. The proposed scheme resolves the symbol synchronization problem which may simplify the encoding and the decoding operations. It shows an important improvement in terms of data speed and bandwidth efficiency compared with conventional MPPM. On the other hand, SMPPM modulation shows a moderate power efficiency. In this article, we present the coding algorithm, expressions of spectral efficiency, normalized power requirements, and the data rate normalized to PPM, and we also present comparison of results with conventional MPPM.

scholarly journals Dual-Branch Pre-Distorted Enhanced ADO-OFDM for Full-Duplex Underwater Optical Wireless Communication System

Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 368
Author(s):  
Zixian Wei ◽  
Yibin Li ◽  
Zhaoming Wang ◽  
Junbin Fang ◽  
Hongyan Fu
Keyword(s):  
Wireless Communication ◽  
Spectral Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Channel Model ◽  
Full Duplex ◽  
Optical Channel ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
Hardware Complexity ◽  
Double Gamma Function

In this paper, dual-branch pre-distorted enhanced asymmetrically clipped direct current (DC) biased optical orthogonal frequency division multiplexing (PEADO-OFDM) for underwater optical wireless communication (UOWC) is firstly proposed and simulated. The performances of PEADO-OFDM on the underwater optical channel model (UOCM) are analyzed and further compared with the typical ADO-OFDM. Using the Monte Carlo method for the modeling of UOCM, we adopt a double-gamma function to represent three different water qualities including clear, coastal and harbor waters. The full-duplex architecture enables the removal of Hermitian symmetry (HS) from conventional optical OFDM and can increase the spectral efficiency at the cost of hardware complexity. A new PEADO-OFDM transmitter is also proposed to reduce the complexity of the transmitter. The simulation results exhibit that our proposed dual-branch PEADO-OFDM scheme outperforms the typical ADO-OFDM scheme in spectral efficiency, bit error rate (BER) and stability over the underwater channels of three different water qualities.

scholarly journals Experimental evaluation of spectral efficiency from a circular array antenna producing a Laguerre–Gauss mode

2020 ◽  
Vol 7 (12) ◽  
pp. 201711
Author(s):  
Ben Allen ◽  
Timothy D. Drysdale ◽  
Chris Stevens
Keyword(s):  
Phase Shift ◽  
Antenna Array ◽  
Spectral Efficiency ◽  
Field Measurements ◽  
Modulation Scheme ◽  
Phase Shift Keying ◽  
Additional Degree ◽  
Shift Keying ◽  
Mode Purity ◽  
Circular Antenna Array

We present the four-dimensional volumetric electromagnetic field measurements ( x , y , z and frequency) of the complex radiated field produced by an 8-element circular antenna array. The array is designed to produce a Laguerre–Gauss (LG) mode l = +1 over the frequency range of 9–10 GHz. We evaluate our findings in terms of far-field LG mode purity and spectral efficiency in terms of the quadrature amplitude modulation (QAM) modulation scheme that can be supported. The application of LG modes in radio systems is as a means of multiplexing several data streams onto the same frequency, polarization and time slot, thus making a highly spectrally efficient transmission system or enhancing radar systems by means of exploiting mode behaviour as an additional degree of freedom. Our results show that for the circular antenna array, we find that mode purity is sufficient to support binary phase shift keying or quadrature phase shift keying modulation over a 0.3 GHz bandwidth, which corresponds to a spectral efficiency of 1.5 b s −1 Hz −1 per mode. Closer to the antennas' design frequency, 256QAM modulation may be supported over a 0.05 GHz band, and which corresponds to a spectral efficiency of 11 b s −1 Hz −1 per mode. We anticipate the practical insights provided in this paper contribute to the successful design of such systems.

scholarly journals Spatial Modulation for Beyond 5G Communications: Capacity Calculation and Link Adaptation

Proceedings ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 26 ◽  
Author(s):  
Anxo Tato ◽  
Carlos Mosquera
Keyword(s):  
Neural Network ◽  
Spectral Efficiency ◽  
Spatial Modulation ◽  
Modulation Scheme ◽  
Hardware Complexity ◽  
Simple Method ◽  
Communications Systems ◽  
Capacity Calculation ◽  
Good Trade ◽  
The One

Spatial Modulation (SM) is a candidate modulation scheme for beyond 5G communications systems due to its reduced hardware complexity and good trade-off between energy and spectral efficiency. This paper proposes two Machine Learning based solutions for easing the implementation of adaptive SM systems. On the one hand, a shallow neural network is shown to be an accurate and simple method for obtaining the capacity of SM. On the other hand, a deep neural network is proposed to select the coding rate in practical adaptive SM systems.

scholarly journals Spectral Efficiency Optimization in Flexi-Grid Long-Haul Optical Systems

2015 ◽  
Vol 33 (13) ◽  
pp. 2735-2742 ◽  
Author(s):  
Tommaso Foggi ◽  
Giulio Colavolpe ◽  
Alberto Bononi ◽  
Paolo Serena
Keyword(s):  
Spectral Efficiency ◽  
Optical Systems ◽  
Efficiency Optimization

Non-Uniform Spectral Amplitude Encoding for Optical Wireless Communication Links through Atmospheric Turbulence

2012 ◽  
Vol 241-244 ◽  
pp. 2192-2195
Author(s):  
Chun Yi Chen ◽  
Hua Min Yang ◽  
Yan Lou ◽  
Zhen Gang Jiang
Keyword(s):  
Wireless Communication ◽  
Atmospheric Turbulence ◽  
Power Efficiency ◽  
Broad Band ◽  
Coherent Beam ◽  
Spectral Amplitude ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
Partially Coherent ◽  
Communication Links

The performance of optical wireless communication (OWC) links based on the spectral amplitude encoding (SAE) of a broad-band spatially partially coherent beam through atmospheric turbulence is analyzed. It has been found that the power efficiency of transmitters of OWC links based on the non-uniform SAE is higher than that based on the uniform SAE. Further, the spectrum division method for the non-uniform SAE of broad-band beams has been proposed. The non-uniform SAE of a broad-band spatially partially coherent beam is an effective method to reduce the performance degradation of OWC links caused by atmospheric turbulence.

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