scholarly journals COMPARATIVE ANALYSIS OF MODULATION SCHEMES USING ADAPTIVE EQUALIZATION AS FADING MITIGATION TECHNIQUE

2012 ◽  
pp. 25-31
Author(s):  
SABITA NAHATA ◽  
SUBRATA BHATTACHARYA
Keyword(s):  
Comparative Analysis ◽  
Data Transmission ◽  
High Speed ◽  
Signal To Noise Ratio ◽  
Multipath Fading ◽  
Symbol Error Rate ◽  
Adaptive Equalization ◽  
Modulation Scheme ◽  
Modulation Schemes ◽  
Mitigation Technique

Inter-symbol interference (ISI) due to multipath fading is a vital problem in high-speed wireless communication which restricts communication quality and capacity. Therefore, in addition to choosing a fading mitigation technique, it is also important to strategically select a modulation scheme for effective data transmission. Recent literature review on wireless standards, such as 3G and 4G indicates that QAM and QPSK are suitable choices for data transmission. In this paper, a comparative analysis on selected modulation schemes is performed in a fading environment. The mitigation of fading is done using adaptive equalization technique. Also, we show that the signal to noise ratio (SNR) is an important parameter to choose. It is observed that, even when an adaptive equalizer is used at the receiver, a very low SNR gives very high symbol error rate (SER). We derive some important conclusions from our simulation result: QPSK shows minimum SER, whereas 256-PSK and 256-PAM perform worse. Given its spectral efficiency and a low SER, the best choice is 256- QAM.

Radio over Fibre Transport of Alamouti-coded MIMO Signals with Self-Recovery Capability

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Jaswinder Kaur ◽  
Vishal Sharma
Keyword(s):  
Spectral Efficiency ◽  
High Speed ◽  
Multipath Fading ◽  
Block Code ◽  
Wireless Channel ◽  
Modulation Scheme ◽  
Wireless Data ◽  
Wireless System ◽  
Radio Over Fibre ◽  
The Impact

AbstractRadio over Fibre (RoF) transport of high-speed wireless data provides a comprehensive solution for the forthcoming highly-reliable and spectral-efficient wireless systems. MIMO is one of the most widely used wireless technologies to increase the system reliability and capacity without any increased demand of power/bandwidth. However, the inherent non-linearities of RoF link and the multipath fading of the wireless channel can degrade the overall performance of the wireless system. In this work, authors demonstrate RoF transport of adaptively modulated MIMO signals and report the improvement in spectral efficiency under the impact of RoF link non-linearity. The transmitter of the proposed RoF based wireless system selects the appropriate modulation scheme with the assumption of perfect channel state information to achieve the acceptable BER at the subscriber end. The spectral efficiency improvement by this self-recovering MIMO-RoF system is evaluated by incorporating orthogonal Space-Time Block Code with 2 × 2 antenna configuration over the frequency-selective Rayleigh fading channel.

Influence of Transmitting Pointing Errors on High Speed WDM-AMI-Is-OWC Transmission System

2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Abdallah Ahmad Shatnawi ◽  
Mohd Nazri Bin Mohd Warip ◽  
Anuar Mat Safar
Keyword(s):  
Wavelength Division Multiplexing ◽  
Data Transmission ◽  
Communication Systems ◽  
High Speed ◽  
Satellite Communication ◽  
Signal To Noise Ratio ◽  
Transmission System ◽  
Eye Diagram ◽  
Satellite Link ◽  
Pointing Errors

AbstractInter-satellite communication is one of the revolutionary techniques that can be used to transmit the high speed date between satellites. However, space turbulences such as transmitting pointing errors play a significant role while designing inter-satellite communication systems. Those turbulences cause shutdown of inter-satellite link due to increase of attenuation during data transmission through link. The present work aims to develop an integrated data transmission system incorporating alternate mark inversion (AMI), wavelength division multiplexing (WDM), and polarization interleaving (PI) scheme for transmitting data 160 Gbps over inter-satellite link of 1,000 km under the influence of space turbulences. The performance of the integrated data transmission of 160 Gbps data up to 1,000 km will be evaluated under the influence of space turbulences by means of signal to noise ratio (SNR), total received power, bit error rate and eye diagram.

scholarly journals Improved Precoder Architecture for Duobinary Transceivers

2017 ◽  
Vol 5 ◽  
Author(s):  
Javier Aguirre Olcoz ◽  
C. Sánchez-Azqueta ◽  
E. Guerrero ◽  
C. Gimeno ◽  
S. Celma
Keyword(s):  
Data Transmission ◽  
High Speed ◽  
Cmos Technology ◽  
Modulation Scheme ◽  
Serial Data ◽  
Soi Cmos

Duobinary modulation is an attractive baseband modulation scheme for high-speed serial data transmission. This work presents a duobinary transceiver with a new precoder architecture that overcomes the glitch vulnerability of the conventional ones. It has been fabricated in a 0.13-μm PD-SOI CMOS technology and achieves 10 Gbps consuming 37 mW. 

scholarly journals Design and Implementation of a Multi-Colour Visible Light Communication System Based on a Light-to-Frequency Receiver

Photonics ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 42 ◽  
Author(s):  
Roger Alexander Martínez-Ciro ◽  
Francisco Eugenio López-Giraldo ◽  
Andrés Felipe Betancur-Perez ◽  
Jose Martín Luna-Rivera
Keyword(s):  
Visible Light ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Visible Light Communication ◽  
Pso Algorithm ◽  
Low Complexity ◽  
Symbol Error Rate ◽  
Modulation Scheme ◽  
Analog To Digital ◽  
Constellation Design

Colour-shift keying (CSK) is a visible light communication (VLC) modulation scheme used in the existing IEEE 802.15.7 standard. In CSK, information is transmitted by changing the light intensities of the RGB LEDs. In this work, a low-complexity VLC system is proposed using CSK modulation and a novel receiver based on a light-to-frequency (LTF) converter. At the receiver, CSK symbols are interpreted and decoded in terms of frequencies, which are processed by a counter module of a generic microcontroller, thus avoiding the use of analog-to-digital converters (ADCs), which results in a low-cost VLC system. The main contributions of this work are summarized in the following key points: (1) A low-complexity receiver for CSK modulation is introduced; (2) A particle swarm optimization (PSO) algorithm for CSK constellation design is suggested considering the restrictions of the LTF based receiver; (3) Experimental and theoretical validation is perfomed for the proposed multi-colour VLC system. The results show that this system can provide a transmission speed of 100 kbps using a 4-CSK-LTF constellation for a symbol error rate (SER) of 10 − 4 and a signal to noise ratio (SNR) around 35 dB. These results suggest that the analysed system could find applications on those scenarios where low transmission speeds and ease of deployment are the goals.

High-speed and Long-reach Hybrid AMI–WDM–PI Inter-satellite Communication System

2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Abdallah Ahmad Shatnawi ◽  
Mohd Nazri Bin Mohd Warip
Keyword(s):  
Wavelength Division Multiplexing ◽  
Data Transmission ◽  
Communication System ◽  
High Speed ◽  
Satellite Communication ◽  
Signal To Noise Ratio ◽  
Eye Diagram ◽  
Wavelength Division ◽  
Received Power ◽  
Current Context

AbstractIn the current context of high-altitude platform communication system, inter-satellite communication is remarkable and highly effective. The present work aims to develop an integrated data transmission system incorporating alternate mark inversion, wavelength-division multiplexing, and polarization interleaving scheme for transmitting data of eight channels, each carrying 20 Gbps data over inter-satellite link of 5,000 km. The performance of the integrated data transmission of 160 Gbps data up to 5,000 km will be evaluated by means of signal-to-noise ratio, total received power, and eye diagram.

scholarly journals Performance Analysis of Post Compensated Long Haul High Speed Coherent Optical OFDM System

2017 ◽  
Vol 7 (1) ◽  
pp. 160
Author(s):  
Divya Dhawan ◽  
Neena Gupta
Keyword(s):  
Performance Analysis ◽  
High Speed ◽  
Signal To Noise Ratio ◽  
Symbol Error Rate ◽  
Optical Signal ◽  
Mapping Method ◽  
Coherent Detection ◽  
Error Vector Magnitude ◽  
Modulation Formats ◽  
Transmission Distance

<p>This paper addresses the performance analysis of OFDM transmission system based on coherent detection over high speed long haul optical links with high spectral efficiency modulation formats such as Quadrature Amplitude Modulation (QAM) as a mapping method prior to the OFDM multicarrier representation. Post compensation is used to compensate for phase noise effects. Coherent detection for signal transmitted at bit rate of 40 Gbps is successfully achieved up to distance of 3200km. Performance is analyzed in terms of Symbol Error Rate and Error Vector Magnitude by varying Optical Signal to Noise Ratio (OSNR) and varying the length of the fiber i.e transmission distance. Transmission performance is also observed through constellation diagrams at different transmission distances and different OSNRs.</p>

Analysis of Inter-Satellite Optical Wireless Communication System

2017 ◽  
Vol 7 (10) ◽  
pp. 10
Author(s):  
Rajbir Singh
Keyword(s):  
Wireless Communication ◽  
Optical Networks ◽  
Data Transmission ◽  
High Speed ◽  
Open Space ◽  
Communication Link ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
High Speed Data ◽  
Speed Data Transmission

Optical networks are bandwidth efficient networks are used for long haul communication providing seamless data transfer. For high speed data transmission in open space between different satellites, Inter-satellite Optical wireless communication (IsOWC) is widely used .In this paper we have evaluated the performance of IsOWC communication link for high speed data transmission .The performance of the system is evaluated on the basis of qualitative parameters such as Q-factor and BER using optisystem simulator.

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