Iraqi Journal of Information and communication technology

Understanding the characteristics of channel propagation is essential for the optimal design of self-interference cancellation (IBFD-UWA) communication systems. UWA channels have propagation characteristics based on the configurations of direct and multipath between a transmitter and a receiver for both self-interference and communication channels. The geometry model and the Bellhop simulator are used to model both channels, respectively, to accommodate any possible changes in the underwater environment. This paper employs self-interference cancellation based on two nodes operating in the IBFD mode, orthogonal frequency division multiplex(OFDM) modulation with quadrature phase-shift keying (QPSK) mapping. By using numerical simulations, it can be shown that the developed model can describe the underwater acoustic environment accurately. The results indicate that local multipath propagation delays can exceed1.4 s with transmission losses of up to80 dB. The SIC requires about 4 seconds to reduce SI signals to background noise levels successfully.

Massive Multiple Input Multiple Output system and physical layer network coding (PNC) are two important technologies that are considered in new generation networks. In this paper, we investigate the effect of increasing the number of antenna elements at user nodes and relay nodes in the presence of PNC. Two-way wireless relay transmission is considered in conjunction with a massive number of antennas at the relay node, assuming wave (mmWave) band channel environment. End-to-end transmission is considered using the 3-D QUAsi Deterministic RadIo channel GenerAtor (QuaDRiGa) channel model. The performance measures used are the bit error rate (BER) and throughput. The main paper findings indicate that the non-PNC system has the same BER performance as the PNC system over the mm Wave channel model while its throughput has improved by about100%. The BER performance is improved only when the number of relay node antennas is much higher than that of the user node. Combining m MIMO with PNC gives better throughput without affecting the BER at high SNR. This is achieved with a reasonable number of antennas at the user nodes.

Non-orthogonal multiple access (NOMA) technology is a significant topic of the present 5G investigation. A possible NOMA approach is Sparse Code Multiple Access (SCMA), which increases next-generation communication’s ability to handle multiple users. In SCMA, codebook design and optimization are crucial components that define the performance of multiple access systems. In this work, the complete design procedure of the SCMA codebook based on interleaving is explained and simulated. Furthermore, a chaotic interleaving based on ArnoldâsCat map is proposed to reduce the computational complexity. The performance of the SCMA codebook based on interleaving is evaluated through comparison with selected codebooks for SCMA multiplexing. The measures used for performance evaluation include bit error rate (BER), peak-to-average power ratio (PAPR),and minimum Euclidian distance (MED). The results show that the proposed codebook with chaotic interleaving achieves comparable performance to the traditional codebook based on interleaving, with less MED and higher BER compared to computer-generated and 16-star QAM codebook design methods but with reduced complexity.

Due to the continuous growth of user traffic demands, there is a need to cope with the increased processing and storage requirements. The increased number of connected end devices causes a problem with carrying the generated loads efficiently. Edge and cloud computing and storage are real solutions to overcome the limitations of end devices on many prospective including computation capabilities, storage capabilities, and power consumption. Terminal devices offload their overflow tasks to the cloud for processing, analysis, and storage. This paper aims to improve computation offloading from edge nodes to the cloud in Internet of Things networks by making efficient decisions using an adaptive offloading algorithm. Offloading is controlled by a processing time offloading threshold value, which is determined automatically by edge nodes based on their traffic intensity and adaptively increased or decreased in loads. The proposed algorithm had been programmed and simulated; experimental evaluations show that the proposed adaptive offloading algorithm minimizes the edge mean response time by up to58%and the cloud mean response time by up to25%compared to the existing fixed, pre-defined offloading threshold value

Zero Trust (ZT) is security model and follow the concept of ânever trust, always verifyâ. ZT require to strict identity verification for devise and clients trying to access recourses on private networks regardless of whether they are sitting within or outside the networks. As opposed to perimeter-based architecture, which makes the assumption that all internal network parties are trusted and all external network parties are untrusted. In enterprise network the internal network parties is automatically seen as trusted entities granting them access to network resources. The insider threat actor has been successful in exploiting their access. So that, enterprise networks become more exposed to inside and outside threads. As a result, we need to add the zero-trust principle to the enterprise network to protect it from the inside. In this paper, the ZT model, is assumed inside the militarized zone. There may be a threat to the sensitive data. Any internal company network users cannot manipulation on his computer without permission from the administrator this is done by the group policies that have been implemented in ZT. This model has been shown to be quite effective in protecting the sensitive data against unauthorized access and also the manipulation by the insider user. Following that, an attack originating from inside of the network was launched against the enterprise and zero trust network. In the enterprise network, the network was effectively attacked, and the attack’s validity was also increased to fully penetrate the enterprise. The attack did not succeed in the zero-trust network because the attacker cannot pass the User Account Control (UAC) to gain the NT authority.

Millimeter wave (mm-Wave) wireless technology has invaded every aspect of modern life because of its ability to transmit data quickly and securely. This paper presented a square patch antenna at a resonance frequencyof26.2GHzfor millimeter wave wireless communication. The proposed antenna consists of single square radiating element. The suggested antenna was designed using CST Microwave Studio’s version 2020 on a Rogers RO 3003lossy substrate with a relative permittivity of 3 . The result of this paper shows a minimumS11of19.34 dB, again of6.97dBi, with bandwidth of2GHzat the resonant frequency of26.2GHz. The gain was enhanced to16dBiand25.8dBiwith a high radiation efficiency by converting the single element patch antenna to a uniform linear array of8elements and uniform planar array of8×8elements respectively. The simulation results show that despite the simple design of the patch (without holes and cracks), which facilitates manufacturing in a small size; However, it achieves higher gain than the more complex designs found in the previous literature to suit mm wave communication requirements. Also, we used CST Microwave Studio for simulation which provides two methods for implementing arrays: the array factor method, which builds virtual arrays (the direct method), or building arrays by repeating the elements depending on the required size of the array, A comparison has been conducted between the numerical analysis of both methods, and the results show that even though the numerical analysis of the second method gives more accurate results that can be close to a manufactured antenna array, it needs high processing ability and time. Creating arrays with array factor may save time and processing ability but the results may not be accurate. Therefore, a relation was driven to show the error that can be added to give precise results.

A blockchain is a secret, scalable, and decentralized p2p network in which all nodes follow similar protocols, preventing any single node from controlling the basic structure. In the blockchain, Bloom filters are used to preserve the privacy of lightweight nodes. The Bloom filter is a memory efficient randomized data structure used to represent a set-in order to support related queries. Bloom filters offer a trade-off between network element size and bandwidth and privacy metrics in untrusted environments. This paper proposes an analysis to evaluate the performance of Bloom filters. The evaluation results are based on the statistical distribution, standard deviation, entropy and y-deniability that are used by the attacker to analysis the leakage of the Bloom filter algorithm. It has shown that less than50%of the filter size was used and the average of anonymity metric was less than66%. Furthermore, the experimental results show that the hide metric measure (y-deniability) depends on the total number of elements in the network and the degree of privacy in the network needs a large number of elements and more bandwidth using the Bloom filter algorithm