scholarly journals LDPC-Coded CAP with Spatial Diversity for UVLC Systems over Generalized-Gamma Fading Channel

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3378
Author(s):  
Hongyan Jiang ◽  
Hongbing Qiu ◽  
Ning He ◽  
Zhonghua Zhao ◽  
Wasiu Popoola ◽  
...  
Keyword(s):  
Characteristic Function ◽  
Bit Error Rate ◽  
Fading Channel ◽  
Visible Light Communication ◽  
Spatial Diversity ◽  
Modulation Scheme ◽  
Low Density ◽  
Parity Check ◽  
Generalized Gamma ◽  
Low Density Parity Check

In this paper, low-density parity-check (LDPC)-coded carrierless amplitude and phase (CAP) modulation with spatial diversity is proposed to mitigate turbulence-induced fading in an underwater visible-light communication (UVLC) channel. Generalized-gamma (GG) distribution was used to model the fading, as this model is valid for weak- and strong-turbulence regimes. On the basis of the characteristic function (CHF) of GG random variables, we derived an approximated bit-error rate (BER) for the CAP modulation scheme with spatial diversity and equal-gain combining (EGC). Furthermore, we simulated the performance of the CAP system with diversity and LDPC for various turbulence conditions and validated the analysis. Obtained results showed that the combination of LDPC and spatial diversity is effective in mitigating turbulence-induced fading, especially when turbulence strength is strong.

scholarly journals BER Performance Analysis of a Concatenated Low Density Parity Check Encoded OFDM System in AWGN and Fading Channels

2009 ◽  
Vol 2 (1) ◽  
pp. 46-53 ◽  
Author(s):  
M. D. Haque ◽  
S. E. Ullah ◽  
M. M. Rahman ◽  
M. Ahmed
Keyword(s):  
Fading Channels ◽  
Bit Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Color Image ◽  
Low Density ◽  
Frequency Division ◽  
Parity Check ◽  
Ofdm System ◽  
Low Density Parity Check ◽  
Ber Performance

In this paper, we investigate the bit error rate (BER) performance of a concatenated low density parity check (LDPC) encoded orthogonal frequency-division multiplexing (OFDM) system on color image transmission. In FEC concatenated channel coding, the OFDM wireless communication system incorporates 1/2-rated convolution encoder under various digital modulations (QPSK, 8PSK, QAM, 8QAM, 16QAM and 32QAM) over an additative white gaussian noise (AWGN) and other fading (Raleigh and Rician) channels. Computer simulation results on BER demonstrate that the LDPC encoded OFDM system outperforms with QAM modulation technique as compared to other digital modulation scheme and the system is highly effective to combat inherent interferences under Rayleigh and Rician fading channels. The transmitted color image is found to have retrieved effectively under noisy and fading situations with implementation of sum-product algorithm, an effective iterative based LDPC decoding scheme. It has also been anticipated that the performance of the communication system degrades with the increasing of noise power. Keywords: Orthogonal frequency division multiplexing (OFDM); Low density parity check (LDPC); Bit error rate (BER). © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2724               J. Sci. Res. 2 (1), 46-53 (2010) 

Performance analysis of protograph-based low-density parity-check codes with spatial diversity

2012 ◽  
Vol 6 (17) ◽  
pp. 2941-2948 ◽  
Author(s):  
Y. Fang ◽  
P. Chen ◽  
L. Wang ◽  
K.-K. Wong ◽  
Francis C.M. Lau
Keyword(s):  
Performance Analysis ◽  
Spatial Diversity ◽  
Low Density ◽  
Parity Check ◽  
Low Density Parity Check ◽  
Parity Check Codes
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