Performance analysis of SAC-OCDMA in free space optical medium using MD and DDW code

Kaur, Gurpreet

doi:10.1109/raecs.2015.7453295

Cited by 17 publications

(7 citation statements)

References 10 publications

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“…The attenuation values for different levels of haze and fog are presented in Fig. 3 [15,29]. The power level of the received optical signal that carries the image is affected by the attenuation caused by the fog conditions.…”

Section: Model Designmentioning

confidence: 99%

Performance of Cipher Image Transmission in Free Space Optics Under Foggy Weather

El-Mottaleb,

Mohamed,

Chehri

et al. 2023

IEEE Access

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This paper proposes a new cipher image transmission system in free space optics system (FSO). A secure and effective image cryptosystem algorithm based on the Choquet fuzzy integral (CFI) technique and the integer wavelet transform is utilized. Numerical simulations are conducted to examine the efficacy of encrypted images against different attacks. The pixel correlation coefficient is found to be quite small for horizontally, vertically, and diagonally in the ranges 2.0557×10 −4 to 0.00057, 9.0256×10 −4 to 0.0045, and 0.00035 to 0.00342, respectively. Additionally, the information entropy of the encrypted image is found to be within the range of 7.9991:7.9972, which is very close to the ideal value of 8. As for the unified average changing intensity (UACI) and the number of pixel change rate (NPCR) metrics, they are in the ranges 33.46 to 33.42 and 99.58 to 99.63, respectively, which are also very close to the optimum values. Median and high pass filters are employed for further enhancing the received decrypted image. Different fog conditions are considered during the transmission of the encrypted image over FSO channel. The signal to noise ratio (SNR), FSO propagation range, and structured similarity index method (SSIM) are metrics used for performance evaluation. The results indicate that images transmitted with ciphering exhibit better performance than plain images. The maximum FSO spans over which the image can propagate in the channel while maintaining good quality are 1790 m, 1198 m, and 947 m under light fog (LF), medium fog (MF), and heavy fog (HF), respectively. In contrast, these ranges extend to 1798 m (LF), 1206 m (MF), and 953 m (HF) with good visual quality when ciphered images are transmitted. Furthermore, the employed enhancement technique demonstrates improvements in SNR and SSIM values for the received images. For instance, when the original image is transmitted in an FSO channel affected by MF, the SNR is -21 dB. This value significantly improves to 12.6 dB when median and high pass filters are applied for enhancement. In addition, the SSIM value goes from 0.18 for the original image to 0.29 when enhancement techniques like median and high pass filters are used at a 1206 m FSO range in MF weather. Consequently, the proposed encrypted image transfer improves image quality. This advancement can be attributed to the CFI encryption algorithm's rigorous security mechanisms, which assure data safety as it travels through the atmosphere.INDEX TERMS Choquet fuzzy integral (CFI), Image encryption, Free space optics (FSO), Signal to noise ratio (SNR), Structured similarity index method (SSIM)

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Section: Model Designmentioning

confidence: 99%

Performance of Cipher Image Transmission in Free Space Optics Under Foggy Weather

El-Mottaleb,

Mohamed,

Chehri

et al. 2023

IEEE Access

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“…where k B , T, and R L , respectively, are the Boltzmann constant, the load resistance of the receiver, and the absolute temperature of the receiver, respectively. The signal-to-noise ratio (SNR) is then expressed as [36,42] follows:…”

Section: Frontiers In Physics Frontiersinorgmentioning

confidence: 99%

Enhancing security and capacity in FSO transmission for next-generation networks using OFDM/OCDMA-based ICSM codes

Abd El-Mottaleb,

Singh,

Alshathri

et al. 2023

Front. Phys.

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In order to address the growing demands for both enhanced security levels and increased transmission capacity, this research proposes a novel approach for free space optical (FSO) transmission. The proposed design incorporates an identity column shift matrix (ICSM) code to ensure robust security. Additionally, capacity enhancement is achieved through the utilization of a 4-level quadrature amplitude modulation (4-QAM) scheme in conjunction with an orthogonal frequency division multiplexing (OFDM) modulator. The performance of the system is evaluated across three channels, each transmitting data at a rate of 20 Gb/s, while operating in an FSO channel that is subjected to varying atmospheric attenuation effects and atmospheric turbulence. Real meteorological data from three different cities [Alexandria, Egypt; Jeddah, Kingdom of Saudi Arabia (KSA); and Hyderabad, India], situated across two continents, are incorporated to demonstrate the practicality of implementing the proposed model in real-world environments. The experimental results reveal that an increase in atmospheric turbulence leads to a higher bit error rate (BER) and lower received optical power (ROP), resulting in degraded data reception. Furthermore, the study examines the impact of weather conditions, indicating that the longest and shortest propagation ranges of 12.5 and 0.286 km, respectively, are achieved under clear weather and heavy dust storms. These conditions yield an ROP of −9.5 dBm and a log (BER) of approximately −2.5. Conversely, in the presence of strong turbulence, the performance further deteriorates. The proposed model demonstrates its ability to transmit a message signal over a distance of 0.8375 km, with a log (BER) of −2.6 under weak atmospheric turbulence. However, under strong atmospheric turbulence at the same distance, the log (BER) increases to −0.5. Regarding specific cities, the FSO range for transmitting information signals is found to be 9.58 km in Jeddah, which decreases to 6.58 km in Alexandria and 5.17 km in Hyderabad due to the increased atmospheric attenuation in these cities.

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“…The simulation is performed using OptiSystem15 for 4 users with code weight of 2. Received power is also calculated under FSO system using equation (7), where PR and PT are received and transmitted power, dR, and dT is receiver and transmitter aperture diameter (m), α is atmospheric attenuation (dB/km), θ is beam divergence (mrad), and D is the range (km), whereas no atmospheric fading is considered while calculating the optical power. A bit stream 0101101110 is transmitted through FSO and a similar bit pattern is observed on oscilloscope as shown in Fig.…”

Section: MD Codementioning

confidence: 99%

“…In literature, different orthogonal codes are available for implementing OCDMA technique [6]. Such as in [7] diagonal double weight (DDW), in [8] modified double weight (MDW) code, in [9] modified quadratic congruence (MQC) codes and in [10] multi-diagonal (MD) codes are implemented. MD code provides zero cross correlation amongst various users placed in the optical network, which supresses the effect of MAI due to other users, and offers flexibility in selecting the code weight for simultaneous users.…”

Section: Introductionmentioning

confidence: 99%

Development of Multi Diagonal based OCDMA System for Free Space Optical Communication System

Chauhan

Kaur

Kumar

2021

Preprint

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The performance of FSO communication link is subject to numerous atmospheric factors in wireless communication like fog, rainfall, and haze which leads to deteriorate the performance of a system in term of BER and power at the receiver side. Due to numerous advantages of OCDMA over other access techniques, it allows various users to access a channel simultaneously without intervention with the other user. It has the ability to provide security, large number of users, privacy, reduce interference from multiple users and operate asynchronously. So, in this paper, Multi-Diagonal codes along with the fiber brags grating filters for Spectral amplitude coded OCDMA technique is developed for FSO system and performance analysis is performed in terms of BER and received power.

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Performance analysis of SAC-OCDMA in free space optical medium using MD and DDW code

Cited by 17 publications

References 10 publications

Performance of Cipher Image Transmission in Free Space Optics Under Foggy Weather

Performance of Cipher Image Transmission in Free Space Optics Under Foggy Weather

Enhancing security and capacity in FSO transmission for next-generation networks using OFDM/OCDMA-based ICSM codes

Development of Multi Diagonal based OCDMA System for Free Space Optical Communication System

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