Nano Communication Networks最新文献

The rates of chemical reactions involved in cell-to-cell communication can serve as a powerful tool for advanced theranostics and in establishing a molecular communication link between bio-transceivers. Reaction rates are usually experimentally measured by quantifying chemical products, which is challenging when several signal transduction mechanisms are involved in the signaling pathway. Without loss of generality, we focus on extracellular vesicle (EV) cell-to-cell signaling and propose a computational method to estimate the chemical reaction rates which characterize a process by which EVs are taken by cells. The method is based on measuring only the time-course of environmental EVs, and eliminates the need to measure either bound or internalized EVs which is usually essential for experimental evaluation of the rates by using advanced molecular imaging modalities. As an alternative to a proposed approximation by a linear system model, our computation exploits a nonlinear system model in which the impact of limited receptor sites on the recipient cell membrane is incorporated. The reaction rates are obtained through a suggested linear and iterative approach as well as a novel way of applying Michaelis–Menten kinetics in the frequency domain. The range of validity of each technique is evaluated by varying the number of free binding sites on the cell membrane in relation to the initial number of environmental EVs. In conclusion, the proposed methods are very effective in assessing the dynamics of the EV uptake using a simple in vitro platform.

Molecular communication (MC) is a novel paradigm for nano-communication networks. Compared with diffusion-based single-input single-out (SISO) systems, multiple-input multiple-output (MIMO) MC with drift systems can effectively mitigate the negative effects of inter symbol interference (ISI), inter link interference (ILI) and noise, further improving transmission efficiency. The modeling complexity of MIMO MC systems inspires the application of deep learning (DL) techniques to establish end-to-end architectures for signal recovery. However, training of the entire end-to-end system is limited by the unknown channel and small training sample size. In this paper, aiming at signal recovery of the newly developed mathematical MIMO MC with drift system model, a Kullback–Leibler divergence (KLD) evolutionary generative adversarial network (EGAN)-based end-to-end learning method is proposed. The end-to-end architecture can be trained offline with both the sampled and fake signals generated by KLD EGAN, even with a small training sample size, and then used to recover online transmitted signals directly. Besides, two traditional detection algorithms denoted as the maximum a posterior (MAP) detector and fixed threshold (FT) detector, are proposed as well for theoretical comparison. Experiments of the effect of different model parameters on the system performance have been carried out. Results validate the effectiveness and robustness of our proposed method compared to other DL-based methods, including the deep neural networks (DNN)-based, the original GAN-based, and the original EGAN-based, in terms of transmission accuracy.

Clique problem has a wide range of applications due to its pattern matching ability. There are various formulations of clique problem like $k$-clique problem, maximum clique problem, etc. The $k$-Clique problem determines whether an arbitrary network has a clique or not whereas maximum clique problem finds the largest clique in a graph. It is already exhibited in the literature that the $k$-clique or maximum clique problem (NP-problem) can be solved asymptotically faster by using quantum algorithms compared to conventional computing. Quantum computing with higher dimensions is gaining popularity due to its large storage capacity and computation power. In this article, we have shown an improved quantum circuit implementation for the $k$-clique problem and maximum clique problem (MCP) with the help of higher-dimensional intermediate temporary qudits for the first time to the best of our knowledge. The cost of the state-of-the-art quantum circuit for the $k$-clique problem is colossal due to a huge number of $n$-qubit Toffoli gates. We have exhibited an improved cost and depth over the circuit by applying a generalized $n$-qubit Toffoli gate decomposition with intermediate ququarts (4-dimensional qudits).

This paper proposes a targeted drug delivery system based on mobile molecular communication (MMC). The system consists of a mobile transmitter and a mobile reactive receiver. The transmitter can sense the required drug concentration and send commands to the receiver for drug delivery in the extracellular fluid (ECF). The commands are sent in the form of bits and the received signal is prone to noise and inter-symbol interference (ISI). Hence, at the receiver, two detection techniques, differential amplitude detector (DAD) and differential energy detector (DED) with ISI mitigation are proposed for MMC. Manchester-coded bits are transmitted using modified concentration shift keying (MCSK). In the proposed detection mechanism, an adaptive threshold technique is used for estimating the number of signaling molecules using the maximum a posteriori probability (MAP) rule. Further in each bit interval, dynamic distance estimation, signal reconstruction, and ISI mitigation are performed. Particle-based simulation for reactive receiver is also carried out to validate the results. A low bit error rate (BER) in the MMC system signifies the promising performance of the drug delivery system.

The occupied area, power consumption, and delay are the most crucial and critical factors in constructing integrated circuits. Due to the reduced occupied area, highly low power consumption, and extremely high speed of quantum-dot cellular automata (QCA) technology, it is one of the finest alternatives to complementary metal–oxide–semiconductor (CMOS) technology for nanoscale construction of circuits. On the other hand, fault tolerance becomes crucial in QCA due to the inherent sensitivity of quantum dots to various sources of errors and faults. These errors can arise from environmental disturbances, manufacturing imperfections, thermal fluctuations, and other factors. The presence of defects or faults can significantly impact the functionality and accuracy of QCA systems, leading to incorrect computation or signal corruption. To address these challenges, fault-tolerant structures are designed in QCA systems. These structures are specifically engineered to detect, tolerate, and mitigate the effects of faults, thereby enhancing the reliability and robustness of QCA-based computation. Fault-tolerant designs aim to ensure that the system can continue to operate correctly even in the presence of defects or faults. In QCA, proposed a fault-tolerant majority gate is necessary to ensure reliable computation in the presence of defects or faults. The fault-tolerant majority gate is a fundamental component in digital logic circuits, and it plays a crucial role in performing computations. It takes multiple input signals and produces an output based on the majority of those inputs. In classical computing, the majority gates are typically implemented using transistors. Therefore, this paper introduces a new and efficient fault-tolerant 3-input majority voter (FT MV3) using 11 simple and rotated cells in the QCA technology, which is 100% and 90.47% tolerant against single-cell and double-cell omission defects. The recommended FT MV3 gate verification is confirmed using some physical proofs. Afterward, to illustrate the performance of the introduced gate, three fault-tolerant computational circuits, including multiplexer, adder and ALU, are presented using the introduced FT MV3 gate. The comparison of the proposed fault tolerant ALU to the best coplanar design shows a 28.80% and 34.01% reduction of cell count and occupied area, respectively. All circuits are simulated using QCADesigner 2.0.3 software.

This paper reports a subwavelength grating (SWG) based multiplexer (MUX) on a silicon photonics platform capable of multiplexing three transverse electric modes. The designed MUX is simulated using a commercial 3D finite-difference time-domain solver and shows broadband operation over the whole C and L optical telecom bands from 1530 nm to 1625 nm wavelength range. The effective indices of the Bloch modes in the SWG waveguides are extracted from the band structure plot. The designed MUX consists of two co-directional coupling regions for fundamental to higher-order mode coupling, with each coupling stage consisting of single-mode and multimode SWG waveguides. The transmission characteristics, viz. transmittance, insertion loss, and return loss, are presented and discussed. The coupling lengths without the tapering regions for TE${}_0$–TE${}_1$ and TE${}_0$–TE${}_2$ mode couplings are $14\mu m$ and $1.48\mu m$, respectively. The transmittance is >78% with the highest insertion loss and return loss of 1.1 dB and –15 dB, respectively. At 1550 nm, the transmission is $>$88%, insertion loss is $<$0.6 dB, and return loss is $<$−15 dB. A uniform under-etch and over-etch of 5 nm are taken for the fabrication tolerance study, which shows a maximum variation of 0.58 dB for the insertion loss with return loss $<$−14.6 dB at 1550 nm. Over the whole simulated range, the insertion loss is $<$1.4 dB, and return loss is $<$−14.6 dB with $\pm$10 nm change in device dimension. A temperature tolerance study with 50 °C and 100 °C rise in temperature has been done, and the device retains its broadband operation over the simulated range. The maximum increase in insertion loss is 0.1 dB for the TE${}_0$–TE${}_2$ coupling, while the overall return loss of the device decreases to $<$−20 dB for the TE${}_0$–TE${}_1$ coupling.

In the nano-scale era, quantum-dot cellular automata (QCA) technology has become an appealing substitute for transistor-based technologies. QCA will be the preferred technology for developing the next generation of digital systems. On the other hand, the full-adder and ripple carry adder (RCA) are the crucial building blocks of complex circuits, the most used structures in digital operations systems, and a practical part of the most well-known complex circuits in QCA technology. In addition, this technology was used to design the full adder for several procedures, like multiplication, subtraction, and division. For this reason, the full adder is generally investigated as a central unit and microprocessor in developing QCA technology. Furthermore, most previous QCA-based adder structures have suffered from some drawbacks, such as a high number of cells, high energy consumption, the high number of gates, and the placement of inputs and outputs in a closed loop; hence, the implementation of an efficient adder with only one gate and a low number of cells, such as exclusive-OR (XOR) gate, can solve all previous problems. Therefore, in this paper, a significantly improved structure of 3-input XOR is suggested based on the promising QCA technology. In addition, a QCA clocking mechanism and explicit cell interaction form the foundation of the proposed QCA-based XOR gate configuration. This gate can be easily converted into an adder circuit while containing a small number of cells and being extremely compressed. The suggested QCA-based XOR design is focused on optimizing a single-bit adder using cellular interaction. The suggested single-bit adder contains 14 cells. Based on this adder, several different RCAs, such as 4, 8, 16, and 32-bit, are designed. The comparison of the proposed single-bit adder to the best coplanar and multi-layer ones shows a 51.72% and 36.36% reduction of cells, respectively. In addition, all suggested designs are verified through simulation using QCADesigner and QCAPro. Finally, many physical validations are provided to approve the functionality of the suggested XOR design.

As the process of scaling down continues at a rapid pace, there is a growing need for an alternative semiconductor device to replace CMOS. One of the alternatives that attracted a lot of attention is called nanomagnetic logic (NML). This is because NML delivers a high device density in addition to a non-volatility of stored information, beyond-CMOS technologies, and device work at room temperature. It is necessary to lower the circuit density and increase the speed of circuits like adders. Using emerging NML logic, we created a full-adder, and ripple carry adder (RCA) with a minimum area. As a result, the invented multilayer-based decimal design makes use of RCA, and full-adder, for innovative 3D topology. We used an NML framework built with perpendicular nanomagnetic (pNML) layers to simulate the characteristics of these devices. With the adder designs that have been offered the latency values are relatively low while performing exhaustive testing. Using pNML technology, a decimal adder has been constructed for the first time in the literature. In addition, simulations are carried out with the help of the Modelsim simulator. During the process of nanomagnetic designing consideration is given to both of these aspects as latency and area. To create an NML circuit, the tool MagCAD is employed. Results are better using the pNML environment-based full adder, RCA and decimal adder.

The manuscript represents miniaturized two-radiating element-based MIMO antennas for the frequency span of 1 THz to 20 THz. Five MIMO antenna structures are designed and analysed by modifying the shape of radiating elements and ground regions to attain better performance. The proposed structures’ performance is compared in terms of return loss, isolation, total gain, directivity, radiation pattern, directivity, peak gain, ECC, TARC, CCL, and TARC. The presented design provides the minimum return loss of −50.85 dB, maximum isolation of 38 dB, maximum bandwidth (S₁₁$<$ −10 dB) of 6.99 THz, maximum normalized directivity of 75°, and peak directivity of 4.635 dB. In addition, the other MIMO performance characteristics, such as the Diversity Gain (DG), Envelop Correlation Coefficient (ECC), Channel Capacity Loss (CCL), and Total Active Reflection Coefficient (TARC) are all within acceptable range. Finally, the presented design is compared with other relevant designs, and a good performance is observed. The proposed structure provides the solution for a superlative MIMO antenna with ultra-wideband, high gain, and compact structure. The proposed design is used for the B5G, THz wave radar, vehicular communications, astronomical radiometric applications imaging, health care, sensing, screening for weapons, explosives, and biohazards identification.