Multi-input And Single-output Research Articles

SIMO-Underwater Visible Light Communication (UVLC) system

The advent of visible light communication (VLC) towards 5G and beyond (5GB) networks opened new doors to unveil the mysteries of unguided mediums such as ocean. The varying physicochemical properties of water introduces the underwater optical turbulence (UOT). The UOT of UVLC link is modelled as unified Gamma-Gamma (GG) distribution fading under moderate-to-strong turbulence channel conditions as well as the misalignment of transceivers following exponential fading are included and studied. This study also contains the effect of UOT which is characterized by multiple water layers within the Monte Carlo simulation framework. The end-to-end (E2E) performances of a Single-Input and Multi-Output (SIMO) underwater VLC (UVLC) system is in consideration of Intensity-Modulation/Direct-Detection (IM/DD) technique which is obtained to fulfill the current communication requirements in hostile aqueous channels. More specifically, the probability distribution function (PDF) and cumulative distribution function (CDF) are derived to obtain the E2E performance metrics of the SIMO-UVLC system in terms of Meijer-G function. Consequently, novel closed-form expressions for average bit-error-rate (ABER) and outage probability of the system are formulated. Finally, the numerical and simulation results are obtained based on the experimental data in mixed water layers of the oceanic environments, and analytically verified through the Monte Carlo simulation approach in harsh channel conditions.

Joint Optimization of URLLC Parameters and Beamforming Design for Multi-RIS-Aided MU-MISO URLLC System

This letter focuses on a novel resource allocation design for a multi-reconfigurable intelligent surface (RIS)-aided multi-input and single-output (MISO) ultra-reliable low-latency communication (URLLC) system. In particular, we formulate the sum-rate maximization problem for joint optimization of block-length and packet-error probability for each user, precoder design at the base-station (BS) and passive beamforming at the RIS. To solve it, we provide an alternating optimization framework which involves the decoupling of original problem into the sub-problems of beamforming design and block-length optimization, and later solving them using general convex approximations. Numerical results validate the fast convergence of the proposed solution. Moreover, the proposed solution achieves upto 40% better performance when compared to random resource allocation and each RIS deployment boost the rate performance by 3–5%.

A novel optimization approach for biohydrogen production using algal biomass

The objective of this research was to employ a low-cost device to produce biohydrogen with several potential applications for clean energy. A multi-input and single-output (MISO) framework was formed during the production process containing three control factors namely time duration, sulfur content, and biomass concentration. The biohydrogen yield during the process was considered the response variable. Furthermore, the response surface approach was used to optimize factors impacting hydrogen generation (RSM). The MISO problem thus was solved using a Taguchi L9 approach to design the experiments with minimum numbers of experimental runs. Analysis of variance (ANOVA) was employed to study the association among data groups. The desirability approach was employed to optimize the operating parameters for the maximum possible yield. Signal to noise ratio curve, ANOVA, and perturbation curve revealed the biomass content as the most important contributor to biohydrogen synthesis. The ideal conditions obtained with the desirability technique were 100 g/L biomass concentration, 95.28 h, and 0.9% sulfur content. The biohydrogen output was anticipated to be 77.84 mL/g VS (Volatile solids). A validation testing shows that the biohydrogen production was 74.32 mL/g VS, with a 4.52% error, which is fairly reasonable.

Biodynamic response of seated human body to vertical and added lateral and roll vibrations

The biodynamic response of 12 subjects to single-axis vertical and multi-axis vertical, lateral and roll excitations was studied to advance understanding of the biodynamics. Different from using single-input and single-output (SISO) method, the apparent masses with multiple inputs were estimated by multi-input and single-output (MISO) method, whose advantage was discussed. By studying the relationship between resonance frequencies and excitation magnitudes, the primary resonance frequencies of vertical apparent masses on seat pan and backrest and fore-and-aft cross-axis apparent masses from vertical acceleration on seat pan had a negative correlation with the weighted root-sum-of-square (r.s.s.) value of excitation magnitudes. Weighting factors of lateral and vertical magnitudes in r.s.s. value were comparable and were much larger than that of roll magnitude. However, the nonlinearity in the apparent mass was more significant or significant only under low r.s.s. value. MISO method appeared more suitable for estimating apparent masses with multiple inputs than SISO method. Practitioner Summary: This paper experimentally studies the dependence of the resonance frequencies in the apparent masses of seated human body on the vibration magnitudes to advance understanding of the biodynamics. The sensitivities of resonance frequencies to lateral and vertical magnitudes are comparable, and much higher than that to roll magnitude. Abbreviations: MISO: multi-input and single-output; SISO: single-input and single-output; r.s.s.: root-sum-of-square; SD: standard deviation; ISVR: Institute of Sound and Vibration Research; r.m.s.: root-mean-square; FRF: frequency response function

An Efficient MPPT Technique Using MIASO Based NARMA-L2 Controller for SPV Generator

This paper describes an efficient solution to make a solar photovoltaic (SPV) generator more promising and acceptable to generate continuous power over the different inherent and extraneous unpredictable factors. A significant problem of the SPV generators is to harness optimal power and its complicated nonlinear power-voltage characteristics with multiple sags and swells under shedding conditions and dynamic insolation patterns. A novel state-of-the-art technique of maximum power point tracking (MPPT) using multi-input and single-output (MIASO) based nonlinear autoregressive moving average controller (NARMA-L2) is used. It is employed to govern two inputs of two SPV generators by controlling one output duty cycle of one boost converter to take out continuous maximum power under macro and micro-dynamic environmental data. It can adjust power supply according to demand under the same or different insolation pattern. One of the strongest reasons to use this technique is to improve the system’s performance to the next level of perfection as it can easily be able to differentiate the global point of maximum power (GPMP) and local point of maximum power (LPMP). Its efficient control capability with a large no of a database is showing its proficiency in uncertain nonlinear environmental conditions, and controllability of separate controllers for each SPV generator. In this paper, the post-performance in terms of least MSE (Mean Square Error) and the maximum efficiency is enhanced up to 98.15%, and 97 % for macro and micro environmental data respectively. The MATLAB simulation results of the SPV generator configuration with the proposed novel MPPT technique are found superior.

Adaptive 3D Imaging for Moving Targets Based on a SIMO InISAR Imaging System in 0.2 THz Band

Terahertz (THz) imaging technology has received increased attention in recent years and has been widely applied, whereas the three-dimensional (3D) imaging for moving targets remains to be solved. In this paper, an adaptive 3D imaging scheme is proposed based on a single input and multi-output (SIMO) interferometric inverse synthetic aperture radar (InISAR) imaging system to achieve 3D images of moving targets in THz band. With a specially designed SIMO antenna array, the angular information of the targets can be determined using the phase response difference in different receiving channels, which then enables accurate tracking by adaptively adjusting the antenna beam direction. On the basis of stable tracking, the high-resolution imaging can be achieved. A combined motion compensation method is proposed to produce well-focused and coherent inverse synthetic aperture radar (ISAR) images from different channels, based on which the interferometric imaging is performed, thus forming the 3D imaging results. Lastly, proof-of-principle experiments were performed with a 0.2 THz SIMO imaging system, verifying the effectiveness of the proposed scheme. Non-cooperative moving targets were accurately tracked and the 3D images obtained clearly identify the targets. Moreover, the dynamic imaging results of the moving targets were achieved. The promising results demonstrate the superiority of the proposed scheme over the existing THz imaging systems in realizing 3D imaging for moving targets. The proposed scheme shows great potential in detecting and monitoring moving targets with non-cooperative movement, including unmanned military vehicles and space debris.

Quasi-Degradation Probability of Two-User NOMA Over Rician Fading Channels

Non-orthogonal multiple access (NOMA) has a great potential to offer a higher spectral efficiency of multi-user wireless networks than orthogonal multiples access (OMA). Previous work has established the condition, referred to quasi-degradation (QD) probability, under which NOMA has no performance loss compared to the capacity-achieving dirty paper coding for the two-user case. Existing results assume Rayleigh fading channels without line-of-sight (LOS). In many practical scenarios, the channel LOS component is critical to the link quality where the channel gain follows a Rician distribution instead of a Rayleigh distribution. In this work, we analyze the QD probability over multi-input and single-output (MISO) channels subject to Rician fading. The QD probability heavily depends on the angle between two user channels, which involves a matrix quadratic form in random vectors and a stochastic matrix. With the deterministic LOS component, the distribution of the matrix quadratic form is non-central that dramatically complicates the derivation of the QD probability. To remedy this difficulty, a series of approximations is proposed that yields a closed-form expression for the QD probability over MISO Rician channels. Numerical results are presented to assess the analysis accuracy and get insights into the optimality of NOMA over Rician fading channels.

The study of seat vibration transmission of a high-speed train based on an improved MISO method

The field measurement was carried out on a high-speed train for the vibration transmission of the seat. The transmissibilities and coherences from the accelerations at the seat base to those on the seat pan and backrest were studied by an improved multi-input and single-output (MISO) system newly proposed by the authors. The improved method has the advantage of calculating the partial coherence independently of the sequences of the inputs and evaluating the contribution of the coherent parts between the inputs to the output compared with the existing method. It was found that although the high-speed train seat was exposed to complex vibrations from different sources, when the three inputs (vertical, lateral and roll accelerations) at the seat base were used as the inputs for MISO models, good multiple coherence functions could be obtained when studying the seat transmissibility to the vertical, lateral or roll vibration at the seat pan and backrest except in the frequency range where the anti-resonances of the inputs located. In such an exceptional case, the unsatisfactory multiple coherence could be explained by the anti-resonances of the input signals, which was further verified by the laboratory experiment. Then the on-site measurement was compared with the laboratory measurement in terms of the estimation of the coherence and transmissibility. Due to the advantages of the laboratory experiment, the contribution from the coherent parts is smaller, and the multiple coherence is higher than the field measurement. In the field measurement, that the inputs were coherent with the ‘noise’ was the main reason for the erroneous estimation of frequency response function (FRF), but the erroneous estimation of FRF resulting from the coherence between the inputs can to some degree be figured out by adopting MISO system. Finally, it was found the peaks in the seat transmissibilities caused by seat modes usually got reduced by the neighboring subject because of the damping brought from the subject.

Robust Adaptive Fault-Tolerant Tracking Control for Nonaffine Stochastic Nonlinear Systems With Full-State Constraints

In this article, the adaptive fault-tolerant tracking control problem of nonaffine stochastic nonlinear systems with actuator failures and full-state constraints is studied. To surmount the design difficulty from nonaffine nonlinear term with multi-input and single-output (MISO) faulty modes, a novel nonlinear fault compensation function with adjustable parameter factor is first introduced to establish a standard adaptive fault-tolerant control (AFTC) strategy based on the mean-value theorem. Then, the remaining nonlinear function, including the partial loss of effectiveness, outage, and stuck cases, together with the constructed compound nonlinear function can be approximated by using the suitable fuzzy-logic system (FLS). Moreover, it is shown that all the states of nonaffine stochastic nonlinear systems are not violating the preset constraint bounds by employing the barrier Lyapunov functions (BLFs). Also, the given adaptive controller can guarantee all the closed-loop signals are uniformly ultimately bounded (UUB) in probability in the sense of fourth-moment within the appropriate compact sets. Finally, two simulation examples are given to demonstrate the validity of the proposed method.

Performance of BER with Different Diversity Techniques for Millimeter-Wave Communication System

In a communications system, a diversity technique is used to enhance the reliability of a message signal by using at least two channels with different characteristics. In this paper, all four possible scenarios are considered: Single-input and singleoutput (SISO), single input and multi-output (SIMO), multipleinput and single-output (MISO), Multiple-input and multiple output (MIMO) systems. Antenna arrays will be used to reduce BER and improve the performance of the system using array gain in the line of sight channel for 60 GHz frequency in an indoor scenario. Single input and single output are investigated before analysis of multiple inputs and multiple output channel in the line of sight (LOS) and multipath propagation. MATLAB simulation has been performed using BPSK modulation. The comparative studies show that the performance of the MIMO diversity technique is more reliable in terms of BER to improve the performance and efficiency of the communication system.

A Simple, Efficient, and Novel Standalone Photovoltaic Inverter Configuration With Reduced Harmonic Distortion

This paper is put forward a novel photovoltaic (PV) inverter topology for maximum solar power utilization, which incorporates a new maximum power point tracking (MPPT) scheme based on shading pattern identification using the artificial neural network, single-input and multi-output (SIMO) converter, and multilevel inverter (MLI). The performance of the proposed MPPT scheme is benchmarked under partially shaded conditions. In continuation, the PV voltage is fed to the SIMO converter, where the converter produces four independent (V1, V2, V3 and V4) voltages with different magnitudes. The MLI converts the dc output voltage of the SIMO converter into ac to feed the utility, with reduced harmonic distortion. This MLI consists of eight switching devices and produces thirty one level ac output voltage with very less harmonic distortion. The salient feature associated with the proposed topology is that the proposed MPPT scheme extracts utmost power in any weather conditions and MLI feeds the utility. An experimental prototype is designed and developed to verify the performance of the proposed PV inverter topology. FPGA Spartan trainer kit is used to program pulses required for the MLI and converter of the proposed topology.

Current and Voltage Mode Resistorless Universal Biquad Filter Using a Single CCCDTA

Current mode (CM) Single-input and multi-output (SIMO) and Voltage mode (VM) Multi-input and single-output (MISO) biquad filters are proposed. The presented configurations use one Current controlled current differencing transconductance amplifier (CCCDTA) and two capacitors without any external resistors, which is easy suited for integrated circuit fabrication. The currentmode filter can realize the second-order low pass, band pass, high pass and band stop responses simultaneously. And the voltage-mode filter can realize all the standard filtering functions from the same structure. The natural frequency (ω) and quality factor (Q) of the filters can be controlled electronically by transconductance of the CCCDTA. Moreover, the proposed filters does not require any impedance matching due to its two input resistance can be independently tuned through the diverse external bias currents of CCCDTA. The influences of the CCCDTA non-idealities are also analyzed and both the active and passive sensitivities are considerably low. This design was simulated in PSPICE. Simulation results showed that their performances in power, bandwidth, out-band rejection and in-band ripple are better than the traditional. Additionally, the experiment results are provided in the paper.

A novel joint transmit beamforming and receive time switching strategy for MISO SWIPT system

In multi-antenna simultaneous wireless information and power transfer (SWIPT) system, beamforming strategy has been widely analyzed due to the increasing signal strength. It can not only increase the signal strength in the direction of the antenna array but also reduce the interference strength, which is a good option for SWIPT system to achieve directional transmission of information and energy. However, the traditional beamforming strategy only uses single beamforming vector, and it does not consider the differences between information and energy in SWIPT system. Actually, interference can also be collected as energy. Based on the traditional beamforming strategy, the resources in SWIPT system are not properly utilized. Therefore, this paper proposes a joint beamforming strategy in multi-input and single-output (MISO) SWIPT system. We extend the traditional single beamforming vector into two beamforming vectors to realize independent control of information and energy based on time switching (TS) receiving mode. In information receiving phase, information beamforming vector is used to carry specific user’s information for information alignment. Since there is an orthogonal relationship between information beamforming vector and channel gain vector, we can achieve to eliminate interference and realize error-free information transmission. In energy receiving phase, energy beamforming vector is used to carry user’s energy. Energy beamforming vector and channel gain vector do not require the orthogonality so that the interference can also be collected as energy. In this paper, we model it as a transmission power optimization (TPO) problem, which is a complex non-convex problem. We firstly transform it into a convex problem, and then, it can be solved using CVX toolbox. Simulation results show that the proposed strategy could increase the energy collection at the same transmission power and also decrease the transmission power at the same energy collection.

Nano TiB2 and TiO2 reinforced composites: A comparative investigation on strengthening mechanisms and predicting mechanical properties via neural network modeling

It is known that the interaction between suspended ceramic nanoparticles (TiB2 and TiO2) in molten alloys affects the strengthening mechanisms of nanoparticle reinforced composites. The present study follows a comparative approach to investigate this phenomenon during casting process of aluminum composites reinforced by TiB2 and TiO2 nanoparticles. Microstructural studies accompanied by the measurements of hardness and tensile strength showed that the highest improvement in mechanical properties of the nanocomposites was achieved when Orowan, load bearing mechanism and Hall-Petch mechanisms were simultaneously engaged in the strengthening process of the metal matrix. In order to predict the mechanical properties, four artificial neural networks based on multi-input and multi-output (MIMO) and single-input and multi-output (SIMO) models were created using Bayesian regularization, and cross validated. Showing errors less than 5%, the developed models can reliably be used to reduce the product development time and fabrication of the aluminum matrix nanocomposites in future under different processing conditions.

Application of full duplex guarantees secure wireless communication

This paper proposes an amplify-and-forward (AF) based scheme for full duplex systems to realize secure wireless communication between two nodes over block fading medium. The paper consider all four possible scenarios: Multiple-input and multipleoutput (MIMO), multiple-input and single-output (MISO), singleinput andmulti-output (SIMO), and single-input and single-output (SISO) systems. We first devise communication protocol of the scheme that does not bring additional communication cost. The core of the protocol is amplify-and-forward process, in which artificial noise sent by the receiver is amplified and retransmitted by the transmitter with information signal back to the receiver. Since the receiver has the knowledge of the noise, the artificial noise only degrades the eavesdropper. Then, we present the form of the artificial noise for the four scenarios respectively. Thereafter, we derive the closed form expressions of secrecy capacity, and reformulate them irrelevant to the channel of the eavesdropper. This makes our scheme valid when the transmitter does not know any information about the eavesdropper. We investigate the solution for the secrecy capacity optimization problem in SISO scenario at first, which can be extended to SIMO, MISO, and MIMO systems. The optimization problems are easy to solve and have analytical solutions. Numerical results are presented to show the validation of our scheme.

New Single Input Multiple Output Type Current Mode Biquad Filter Using OTAs

This paper presents a new current mode (CM) single-input and multi-output (SIMO)-type biquad using two multiple output OTAs and one current follower as an active device and having two grounded capacitors. This SIMO type circuit realizes all the five filter functions as low pass, band pass, high pass, band reject and all pass filter transfer functions simultaneously. This circuit has the unity gain transfer function for all the five types of filters. The circuit enjoys electronic tunability of angular frequency and bandwidth. The 0.18 μm TSMC technology process parameters have been utilized to test and verify the performance characteristics of the circuit using PSPICE. The sensitivity analysis, transient response and calculations of total harmonic distortion have also been shown.

Optimal Operation of Combined Heat and Power System Based on Forecasted Energy Prices in Real-Time Markets

This paper develops a discrete operation optimization model for combined heat and powers (CHPs) in deregulated energy markets to maximize owners’ profits, where energy price forecasting is included. First, a single input and multi-output (SIMO) model for typical CHPs is established, considering the varying ratio between heat and electricity outputs at different loading levels. Then, the energy prices are forecasted with a gray forecasting model and revised in real-time based on the actual prices by using the least squares method. At last, a discrete optimization model and corresponding dynamic programming algorithm are developed to design the optimal operation strategies for CHPs in real-time. Based on the forecasted prices, the potential operating strategy which may produce the maximum profits is pre-developed. Dynamic modification is then conducted to adjust the pre-developed operating strategy after the actual prices are known. The proposed method is implemented on a 1 MW CHP on a typical day. Results show the optimized profits comply well with those derived from real-time prices after considering dynamic modification process.

A multi-input and multi-output design on automotive engine management system

Lookup table is widely used in automotive industry for the design of engine control units (ECU). Together with a proportional-integral controller, a feed-forward and feedback control scheme is often adopted for automotive engine management system (EMS). Usually, an ECU has a structure of multi-input and single-output (MISO). Therefore, if there are multiple objectives proposed in EMS, there would be corresponding numbers of ECUs that need to be designed. In this situation, huge efforts and time were spent on calibration. In this work, a multi-input and multi-out (MIMO) approach based on model predictive control (MPC) was presented for the automatic cruise system of automotive engine. The results show that the tracking of engine speed command and the regulation of air/fuel ratio (AFR) can be achieved simultaneously under the new scheme. The mean absolute error (MAE) for engine speed control is 0.037, and the MAE for air fuel ratio is 0.069.

基于MISO折线模糊神经网络的优化算法

In this paper, we proposed a novel multi-input and single-output (MISO) polygonal fuzzy neural network based on polygonal fuzzy numbers and their extension operations. A uniformity analysis of this network is provided for cases where an activation function is nonnegative continuous and monotonous. In order to avoid the complex calculation of the partial derivatives of error functions related to connection weights and threshold values, we use the Hebb rule and the particle swarm algorithm to design two kinds of optimal learning algorithms to handle these two calculations, respectively. Using a simulation example, we analyzed and compared the two kinds of optimization algorithms in detail. The results showed that our optimization algorithms based on MISO fuzzy neural networks exhibited randomness and parameters diversity, but the Hebb algorithm was simple and easy to realize. The particle algorithm was stable and converged quickly

Optimization algorithms for MISO polygonal fuzzy neural networks

In this paper, we proposed a novel multi-input and single-output (MISO) polygonal fuzzy neural network based on polygonal fuzzy numbers and their extension operations. A uniformity analysis of this network is provided for cases where an activation function is nonnegative continuous and monotonous. In order to avoid the complex calculation of the partial derivatives of error functions related to connection weights and threshold values, we use the Hebb rule and the particle swarm algorithm to design two kinds of optimal learning algorithms to handle these two calculations, respectively. Using a simulation example, we analyzed and compared the two kinds of optimization algorithms in detail. The results showed that our optimization algorithms based on MISO fuzzy neural networks exhibited randomness and parameters diversity, but the Hebb algorithm was simple and easy to realize. The particle algorithm was stable and converged quickly