A Scaling Scheme for DCT Precoded Optical Intensity-Modulated Direct Detection Systems

A scaling technique is employed to improve the performance of a Discrete Cosine Transform (DCT) precoded optical intensity-modulated direct detection (IM/DD) OFDM system, which fully exploits the dynamic range of a digital-to-analog converter (DAC). The theoretical analysis shows that the proposed scaling scheme can improve the BER performance of DCT precoded and scaled OFDM systems. The experiment results also show that the proposed scheme significantly improves the BER performance without changing the receiver structure. The measured received sensitivity at a BER of 10−3for a 4 G samples/s (2.7 Gbits/s) DCT precoded and scaled OFDM signal and after 100 km standard single-mode fiber (SMF) transmission has been improved by 3 and 1.3 dB when compared with the original OFDM system and conventional DCT precoded OFDM system, respectively.

Download Full-text

Performance Limitations of an Optical Intensity Modulated-Direct Detection Transmission System Due to Polarization Mode Dispersion in a Single Mode Fiber

MILCOM 2006 ◽

10.1109/milcom.2006.302254 ◽

2006 ◽

Author(s):

M. S. Islam ◽

S. P. Majumder ◽

M. Rezwan Khan

Keyword(s):

Direct Detection ◽

Polarization Mode Dispersion ◽

Single Mode ◽

Single Mode Fiber ◽

Transmission System ◽

Polarization Mode ◽

Optical Intensity ◽

Intensity Modulated ◽

Mode Dispersion ◽

Performance Limitations

Download Full-text

Efficient Blind Adaptive CSE to Reduce Cyclic Prefix Length in Direct Detection Optical OFDM Systems

Journal of Optical Communications ◽

10.1515/joc-2018-0165 ◽

2019 ◽

Vol 0 (0) ◽

Author(s):

Asmaa Benieddi ◽

Sid Ahmed Elahmar

Keyword(s):

Orthogonal Frequency Division Multiplexing ◽

Direct Detection ◽

Group Velocity Dispersion ◽

Signal To Noise Ratio ◽

Single Mode ◽

Optical Signal ◽

Single Mode Fiber ◽

Cyclic Prefix ◽

Ofdm Systems ◽

Blind Adaptive

AbstractDirect detection optical orthogonal frequency division multiplexing (DDO-OFDM) systems for a long-reach of standard single mode fiber (SSMF) require a large length of cyclic prefix (CP) to avoid the inter-symbol interference (ISI) effect caused by group velocity dispersion (GVD). Unfortunately, this method is inefficient due to the energy wasted in CP samples. In order to reduce the CP length and to mitigate the residual ISI, a novel blind adaptive channel shortening equalizer (CSE) is proposed in this paper. Based on the orthogonality between subcarriers in the fast Fourier transform (FFT) property, the proposed algorithm attempts to minimize the sum-squared correlation (SSCM) between each sample located in a well-defined window to update the CSE coefficients. Thus, the combined channel-CSE response is shortened. Therefore, it can cancel the residual ISI effect due to the GVD and the short CP length. The performance of the system is evaluated on basis of bit error rate (BER) versus optical signal to noise ratio (OSNR) for different CP lengths. The simulation results validate the new algorithm SSCM and show that it can reduce the CP length with a much better system improvement than existing algorithms.

Download Full-text

Theoretical and Experimental Investigation of Direct Detection Optical OFDM Systems with Clipping and Normalization

Journal of Electrical and Computer Engineering ◽

10.1155/2018/1839403 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Jiang Wu ◽

Zhongpeng Wang

Keyword(s):

Orthogonal Frequency Division Multiplexing ◽

Direct Detection ◽

Single Mode ◽

Superior Performance ◽

Ofdm Systems ◽

Ofdm System ◽

Transmission Scheme ◽

Awgn Channel ◽

Ofdm Signal ◽

Optical Ofdm

A data clipping and normalization technique is employed to improve the performance of the overall direct detection optical orthogonal frequency division multiplexing (DCO-OFDM) system. A detailed analysis of clipping distortion introduced by digital clipping and normalization is provided. The normalization operation amplifies the clipped data signal to the maximum input amplitude of a digital-to-analog converter (DAC). Based on the analysis, a BER formula of the proposed scheme is derived over the AWGN channel and single fiber channel. Performance of an optical clipped OFDM with normalization is assessed through numerical simulations and Monte Claro simulation over the AWGN channel. Theoretical analysis and simulation results both show that the clipping and normalization scheme can greatly improve the BER of an optical OFDM. In particular, BER performance of the proposed transmission scheme was measured in a practical OFDM transmission platform. The measured experimental results show that the clipped and amplified OFDM signal exhibits superior performance in comparison with the conventional OFDM signal. The received sensitivity at a BER of 10−3 for a 4 Gsamples/s (2.6667 Gbits/s) clipped and normalized OFDM signal with clipping ratio of 4 after 100 km standard single-mode fiber (SMF) transmission was improved by 4.3 dB when compared with the conventional OFDM system. The measured results also showed that the clipped OFDM signal exhibits superior performance in comparison with the conventional OFDM signal. Therefore, a clipping and normalization at the transmitter is most effective, and a substantial performance improvement can be obtained by a simple normalization after clipping.

Download Full-text

Demonstration of C-band 112G PAM-4 transmission over 80-km stand-single mode fiber based on direct-detection

Optics Communications ◽

10.1016/j.optcom.2018.02.032 ◽

2018 ◽

Vol 424 ◽

pp. 32-36

Author(s):

Yiran Wei ◽

Jianjun Yu ◽

Jianyang Shi ◽

Junwen Zhang ◽

Jing He ◽

...

Keyword(s):

Direct Detection ◽

Single Mode ◽

Single Mode Fiber

Download Full-text

Transmission of a 213.7-Gb/s single-polarization direct-detection optical OFDM superchannel over 720-km standard single mode fiber with EDFA-only amplification

36th European Conference and Exhibition on Optical Communication ◽

10.1109/ecoc.2010.5621385 ◽

2010 ◽

Cited By ~ 5

Author(s):

Wei-Ren Peng ◽

Hidenori Takahashi ◽

Itsuro Morita ◽

Hideaki Tanaka

Keyword(s):

Direct Detection ◽

Single Mode ◽

Single Mode Fiber ◽

Optical Ofdm ◽

Single Polarization

Download Full-text

Effect of Polarization Mode Dispersion on Direct Detection CPFSK Optical Transmission System in a Single Mode Fiber

2006 10th IEEE Singapore International Conference on Communication Systems ◽

10.1109/iccs.2006.301513 ◽

2006 ◽

Author(s):

M. S. Islam ◽

S. P. Majumder

Keyword(s):

Optical Transmission ◽

Direct Detection ◽

Polarization Mode Dispersion ◽

Single Mode ◽

Single Mode Fiber ◽

Transmission System ◽

Polarization Mode ◽

Mode Dispersion

Download Full-text

Analysis of secured Optical Orthogonal Frequency Division Multiplexed System

Journal of Optical Communications ◽

10.1515/joc-2016-0075 ◽

2017 ◽

Vol 38 (2) ◽

Cited By ~ 1

Author(s):

Harsimranjit Singh Gill ◽

Kamaljit Singh Bhatia ◽

Sandeep Singh Gill

Keyword(s):

Signal To Noise Ratio ◽

Average Power ◽

Single Mode ◽

Optical Signal ◽

Data Encryption ◽

Single Mode Fiber ◽

Frequency Division ◽

Ofdm Systems ◽

Ofdm Signal ◽

Coded Ofdm

AbstractIn this paper, security issues for optical orthogonal frequency division multiplexed (OFDM) systems are emphasized. The encryption has been done on the data of coded OFDM symbols using data encryption standard (DES) algorithm before transmitting through the fiber. The results obtained justify that the DES provides better security to the input data without further bandwidth requirement. The data is transmitted to a distance of 1,000 km in a single-mode fiber with 16-quadrature amplitude modulation. The peak-to-average power ratio and optical signal-to-noise ratio of secure coded OFDM signal is fairly better than the conventional OFDM signal.

Download Full-text

Interference Cancellation for Underwater Environment

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.b1032.0782s419 ◽

2019 ◽

Vol 8 (2S4) ◽

pp. 174-176

Keyword(s):

Optical Communication ◽

Interference Cancellation ◽

Spatial Diversity ◽

Ofdm Systems ◽

Ofdm System ◽

Wireless Optical Communication ◽

Underwater Environment ◽

Mimo Ofdm ◽

Environment Regulation ◽

Ber Performance

In this paper, Performance of MIMO-OFDM systems in underwater wireless optical communication are studied. The execution of MIMO underwater environment regulation is examined. To alleviate turbulence induced fading, spatial diversity over underwater environment link is used. Furthermore, scattering and absorption are considered in the analysis. Analytical BER computations are fundamentally the same as simulated results. Interference cancellation inclusion in OFDM system has better BER performance than conventional method. So, by IC can accomplish high BER productivity than conventional system. Moreover, simulated results demonstrate that OFDM using IC plot has better BER execution for underwater environment.

Download Full-text