This paper introduces a novel free space optics (FSO) communication system for future-generation high-speed networks. The proposed system integrates orbital angular momentum (OAM) modes with an ...optical code division multiple access (OCDMA) technique. Two OAM beams are used (LG0,0 and LG0,10), each of which is used for transmitting three independent channels. Each channel is assigned by fixed right shift (FRS) codes and carries 10 Gbps of information data. The performance of the proposed model is evaluated under different foggy and dust storm conditions. Furthermore, the performance of two cities with different geographical locations, Alexandria city in Egypt and Srinagar city in India, is investigated to demonstrate its ability to be implemented in future generations. Bit error rate (BER), eye diagrams, received optical power (ROP), and channel capacity are used for studying the performance of the proposed system. The observed simulation results show successful transmission of 60 Gbps overall capacity with the longest propagation FSO range for Alexandria city, which is 1400 m. Because dust storms have a large attenuation when compared to different foggy conditions, the proposed model had the shortest propagation range of 315 m under low dust (LD), 105 m under moderate dust (MD), and 40 m under heavy dust (HD). Furthermore, the cloudy weather conditions that affect Srinagar city, which is considered a hilly area, make our suggested model achieve 1000 m.
One dimensional encoding in optical communications has limitations in terms of the number of supported users and large bandwidth consumption. This study presents a new algorithm to generate ...two-dimensional (2D) encoding utilizing permutation vectors (PV) theory for incoherent multiple access network to suppress multiple access interference (MAI) and system complexity. The proposed code design approach is based on spectral/spatial techniques for code generation. All possible combinations of PV code-sets are obtained by utilizing all permutations of the vectors with the repetition of each vector weight (W) times. Furthermore, the 2D-PV code-set is constructed by combining two code sequences of the 1D-PV code. Furthermore, the transmitter–receiver architecture of the 2D-PV spectral/spatial (S/S) code based OCDMA system is presented. The Gaussian approximation is used to analyze the performance of the proposed OCDMA system with 2D- PV code by considering various noise sources (shot, thermal, and PIIN). Results indicate that the 2D-PV code provides increased cardinality by eliminating phase induced intensity noise (PIIN) effects with a minimum likelihood of interference between multiple user data. Simulation implementations validate the proposed system performance for an agreeable bit error rate (BER) of 10
–9
The article proposes a new classification method based on implementing the high-speed search tools for the indexed data structure created on the etalon set of features, which has significant ...advantages in processing speed compared to the traditional approaches. The classifier is represented as two-stage processing, where at the first stage the class for the separate object descriptor is determined, and at the second stage, the resulting class of the object is determined based on the obtained set of local solutions. The developed method is based on the preliminary construction of the indexed hash structures for the set of descriptors of the base of the etalon images. Implementing the hash representation allows for increasing the speed of identification or classification of visual objects. A comparative experiment with the traditional method of voting has been conducted, where the linear search for the nearest descriptor has been implemented for the identification without the use of prior creation of the indexed hash representation of the etalons. In the experiment, we have gained in processing speed for the developed method compared to the traditional over 10 times. The gain in processing speed increases proportionally with the number of the etalons and the number of the descriptors in the descriptions. The experiment has shown that the efficiency of the method can be enhanced by varying the values of its parameters and adapting to the properties of the data.
In this paper the K-Nearest Neighbor (KNN) model which is one of machine learning (ML) algorithm is applied to distinguish between the four distinct Hermite Gaussian (HG) beams (HG00, HG01, HG02, and ...HG03) in mode division multiplexed (MDM)-free space optics (FSO) communication system. First, the performance of the FSO system using these different HG beams is investigated for rainy weather conditions in various Indian cities having distinct geographical locations. Transmission performance is evaluated in terms of quality (Q)-factor, signal-to-noise ratio (SNR), bit error rate (BER), and eye diagrams. Then, the values of the BER for the different HG beams are applied to the KNN ML model as to classify between them. HG modes are used for capacity enhancement. Results indicate that 80 Gbps can be transmitted over 1000 m in Hyderabad, 800 m in Pune, 580 m in Chennai, and 475 m in Mumbai at
log (BER)
~
10
-
15
, Q-factor less than 8, and SNR ~ 10 dB. Additionally, the K-Nearest Neighbor (KNN) ML model shows 94% classification accuracy between four HG beams.
This paper optimizes the design of two-dimensional enhanced multi diagonal (2D-EMD) code and conventional spectral/spatial (SS) optical code division multiple access system architecture for large ...capacity at relatively low powers. The existing 2D-EMD coding scheme is optimized by reducing the weight and length of spatial code sequence to minimize power losses across the encoding and decoding arrangement. Moreover, a complete system architecture is developed by optimizing the structures of conventional 2D SS optical line terminal (OLT) and remote node (RN) racks to reduce the use to long span optical fibers between the central office and subscribers premises. The optimized system architecture is implemented as per passive optical network (PON) specification in Optisystem and analysis is performed using several pivotal performance parameters. It is observed that optimization of the 2D-EMD (2D-OEMD) coding algorithm elevates both transmission capacity and cardinality at received powers as low as of − 10 dBm. Moreover, the new OLT and RN racks significantly reduces the length and number of optical fibers between the OLT and receiver modules. Consequently, the optimized SS 2D-OEMD system can support 192 subscribers at 2 Gbps of data each over the span of 25 km single mode fiber. Consequently, the proposed architecture can be adapted for numerous application with high bandwidth requirement including next generation PON, back bone for free space optical and fifth generation communication systems.
Due to rapid development in secured technological devices, the efficient implementation of a large field-size elliptic curve cryptosystem (ECC) is becoming demanding in many critical applications. ...Therefore, this paper presents a new Montgomery point multiplication (PM) algorithm to optimize and balance the signal flow and resource utilization efficiency. Thereafter, we have presented an efficient ECC processor architecture over <inline-formula> <tex-math notation="LaTeX">GF(2^{m}) </tex-math></inline-formula> with m = 409 and 571 for the proposed Montgomery PM algorithm. Finally, we have given a detailed comparison and performance analysis (in terms of area-delay product) to show that the proposed cryptographic processor has superior performance as compared to the competing designs. The implementation results after place & route on Xilinx Virtex 7 and Kintex Ultrascale+ are provided. The achieved results reveal that the proposed large field-size ECC processor (and the proposed design strategy) can be extended and applied in many security-demanding applications.
A new variable weight zero cross correlation code (VZCC) is designed that support different class of services in spectral encoding for OCDMA scheme. The proposed code has many benefits, such as the ...easy and strong mathematical way of code construction, acceptable code length, variable ZCC. A transmitter–receiver structure of the VZCC OCDMA system is presented. The performance of the proposed VZCC OCDMA system with noise sources at the direct detection scheme is studied using gaussian approximation. It is observed that the VZCC OCDMA scheme is able to accommodate more users in contrast to the reported techniques having a privilege of triple play services. For BER 10
–9
the Modified Double Weight (MDW), Modified Quadratic Congruence (MQC), Modified Frequency Hopping (MFH), Hadamard, and VZCC supports 68, 70, 62, 18, and 145 users, respectively at − 10 dBm power.
Free Space Optics (FSO) has emerged as a viable solution to meet the growing demand for high bandwidth, secure data transmission, and high speed. However, the FSO system is highly susceptible to ...environmental factors, with precipitation in particular having a significant impact on FSO links. Optical loss, phase fluctuation, and multipath fading of the received optical power are all caused by these external factors. From this perspective, to improve the system’s performance in such conditions, a novel image encryption technique based on the Choquet Fuzzy Integral (CFI) in conjunction with the integer wavelet transform is proposed. The security of the proposed method is demonstrated via analysis security on the one, and its efficacy in terms of transmission performance of an encrypted image over an FSO channel exposed to rainy weather conditions is analyzed on the other. Authentic meteorological data from two distinct cities are considered to demonstrate the model’s real-world applicability: Alexandria, Egypt, in Africa, and Jeddah, Kingdom of Saudi Arabia (KSA), in Asia. To evaluate the system’s performance, a variety of metrics such as FSO range, Signal-to-Noise Ratio (SNR), Peak Signal-to-Noise Ratio (PSNR), and the Structural Similarity Index Method (SSIM) are used. Furthermore, the findings from studying the impact of weather conditions reveal that, as the intensity of rainfall increases, the encrypted image experiences a reduction in its propagation range within the FSO channel. For example, under heavy rain (HR) conditions, the maximum FSO range for high-quality received encrypted images is 1055 m, which extends to 2290 m as rain intensity decreases (for light rain). In terms of the two cities, Jeddah, with its lower average rainfall intensity compared to Alexandria, allows the encrypted image to travel an additional 2400 m.
This paper presents high attitude platform Free space optics (HAP-FSO) channels using various filtering operations for fifth generation (5G) system. Performance analysis is done utilizing different ...types of optical filters such as Bessel, Trapezoidal, Gaussian and Rectangular. A comparison is carried out between our proposed scheme and reported counterpart. HAP-FSO performances have been investigated to be taken into account the effects of different factors such as transmission distance, transmitting aperture diameter, beam divergence, transmitter aperture diameter, and receiver diameter. Simulation analysis is performed in highly recognized software tool called
Optisystem™
to validate the implementation and performance of the proposed system. It is found that the most extreme quality calculation can be accomplished via utilizing Gaussian optical channel in comparison with distinctive optical channels. In particular, with increasing data rate up to 5G coverage range application, minimum BER value is increased for all type of filters. But the trapezoidal filter achieved better results compared with other types of filters.
In this work, we have proposed an iterative optimization model for allocating spectral resources in optical networks. The proposed model gives spatial routes and spatial bandwidth allocations in ...optical networks with variable data-rates, modulation schemes, and optical reach adaptation. We have also proposed an algorithm which allocates continuous and contiguous block of frequency slots (FS) between transponders which forms bandwidth partitions. The primary objective of the bandwidth partition is to reduce spatial fragmentation. The integrated approach includes the routing information from using the optimization model and the categorical spectrum allocation from using the proposed algorithm. The integrated approach has been used for dynamic traffic to improve network performance in terms of bandwidth blocking, link utilization, and fragmentation metrics. It has been shown that the FS utilization (FSU) and link utilization (LU) largely increase in the proposed integrated scheme with 80% LU compared to shortest path first (SPF) routing with LU as low as 20%. Similarly, the standard deviation between FSU in the proposed scheme is approximately 5% compared to 25% in other schemes which shows that the FSU sufficiently increases in the integrated approach.
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