Multiple-input Single-output Techniques Research Articles

Implementation of Single Band Dual-Polarized for Satellite Communication using MISO System

MISO (Multiple-Input Single-Output) similar architecture of most terrestrial wireless network networks instead of more and more scientists striving to apply MISO technology to satellite technology, it can be used to achieve a lower rate of application bit error and risk of complications, while managing increased power boost technology. In mitigating the phenomenon increasingly crowded networks, sites, and increasingly strained sources and frequency of orbital interacting. That channel electricity, bit error rate, and single-band dual-polarized probabilities of MISO outage communication systems are evaluated in the paper. In the first step, when the XPD (Cross-Polarization Discrimination) antenna in a certain organism is greater than 1. With the XPD change, the channel throughput increases in scale linearly. Second, under BPSK modulation, it analyses the bit error rate BER of the specification. The design incorporates a sufficiently low (BER) when the SNR is substantial; analysis of the frequency of outage of a distributed MISO system demonstrated when the signal to noise ratio (SNR) is massive, the handset would maintain the prospect of an outage low enough. Assessment of the spectral range of satellite communication, in the analysis process, the criteria of the rice channel are applied to the channel, review excluding certain traits of the dual-polarized satellite MISO. The public would provide great feedback for the productivity of the future of MISO satellite technology. In a previous paper, the author designed a channel modeling dual-band for satellite communication using the MIMO technique. Using this technique, the system cannot achieve greater performance and at the same time using a dual-band will decrease the system's capability. To decrease the above issues, the paper introduces a new method called the MISO system. Using the MISO technique, the system can gain high performance and the system will get greater bandwidth, BER, and SNR. The advantage of using single-band dual-polarized is, uplink and a downlink frequency of the satellite can be calculated very easily and accurately.

Investigation of multiple input–single output technique for wireless optical communication system under coastal water

In this paper, a simulation was proposed to study underwater visible light communication (UVLC) system using a multiple input–single output (MISO) technique with different modulation schemes under coastal water. MISO technique has enhanced the distance link with high speed data rate compared with the traditional technique of single input–single output (SISO), MISO technique was also employed to examine the performance of BER and data rate under different Jerlov types of coastal water. Various impairments such as distance link, pathloss, channel loss and the attenuation of coastal water were introduced into the transmission of the optical signal to assess the reliability of the MISO technique. The simulation analysis shows the proposed technique can outperform the SISO technique in terms of BER and Q. factor. Moreover, the Q. factor of up to 16 dB and 10−10 BER under J9C of coastal water by using (4Tx/1Rx) technique. The radiation angle of LED and the attenuation coefficient of coastal water were restricted for achieving longer distances link. The system accomplished a distance link about 2.9 and 13.5 m for coastal water types J9C and JIC respectively. The 32-PPM is a suitable modulation for obtaining a best distance link for LoS and NLoS scenarios.

Performance Evaluation on Single-Input Single-Output and Multiple-Input Single-Output Technique in Visible Light Communication

Performance Evaluation on Single-Input Single-Output and Multiple-Input Single-Output Technique in Visible Light Communication

Model updating of uncertain parameters of carbon/epoxy composite plates from experimental modal data

This work presents a methodology to obtain physically-sound models of composite structure laminates using a combination of modal analysis, numerical modelling and parameter updating, avoiding the common uncertainties on the constructions of similar numerical models. Moreover this model establishes the baseline (pristine situation) of the dynamic behaviour of the set of composite plates. Therefore it could be applied for condition assessment or quality manufacturing control of existing structures through a non-destructive Structural Health Monitoring (SHM), and hence it could help to detect degradation or defects of the composite components. The driven data of the methodology were the modal frequencies and shapes of composite plates. To obtain these values an extensive experimental campaign of modal analysis has been performed on a set of carbon/epoxy laminates. A multiple input single output technique has been applied, using a roving hammer exciting the plates at evenly distributed Degrees of Freedom (DoF), and a mono-axial accelerometer attached to a single DoF reference point. The use of a high dense grid of points has allowed to identify a number of natural frequencies greater than usual in similar works, as well as improving the smoothness of the mode shape. Modal characteristics numerically obtained from a Finite Element Method (FEM) model based on manufacturer reference data were compared with experimental results. This baseline model was updated through a gradient based optimization algorithm. Before the process of model updating, a sensitivity analysis has been performed to identify the driven uncertain parameters using a Montecarlo approach. This technique reduces the number of parameters to be optimized to a small set increasing the efficiency of the methodology. As a result of the whole process, a physically more accurate model is obtained on which discrepancies with the corresponding experimentally measured modal parameters are drastically reduced. Analysis of the consistency of the adjusted numerical parameters has been done with alternative experimental tests (Quasi Static Loading (QSL) and Ultrasonic inspection).

Layered Division Multiplexing With Distributed Multiple-Input Single-Output Schemes

Single frequency networks (SFNs) provides an increased spectral efficiency compared to the traditional multiple frequency networks. However, some coverage areas in SFN can be affected by destructive interferences. In order to reduce these situations, distributed multiple-input single-output (MISO) schemes have been adopted in the new digital terrestrial television standards, Alamouti in DVB-T2 and transmit diversity code filter sets in ATSC 3.0. On the other hand, layered division multiplexing (LDM), a non-orthogonal multiple access technology, has been adopted in ATSC 3.0 due to its spectral efficiency increase compared to time or frequency division multiplexing. The LDM signal is formed by a power superposition of two independent signals, which are designed for different reception conditions (mobile and fixed-rooftop). The combination of distributed MISO and LDM techniques has not been evaluated yet. In this paper, the joint transmission of LDM with distributed MISO is analyzed in terms of complexity and the joint performance is evaluated by means of physical layer simulations.

Reduction in transmitter power requirement for earth-to-satellite and satellite-to-earth free space optical links with spatial diversity

In the scenario of first laser communication relay satellite being launched into geostationary earth orbit, we evaluate the reduction in transmitter power requirement for earth-to-satellite and satellite-to-earth free space optical links in presence of turbulence and various weather conditions using spatial diversity technique. In channel modeling, Beer Lambert Law incorporates the weather effects. The log-normal probability density function (pdf) models weak turbulence and gamma–gamma pdf moderate to strong turbulence. Using the combined channel state pdf, bit error rate (BER) expressions are derived for on-off keying (OOK), M-ary pulse position modulation (M-PPM) and M-ary differential PPM (M-DPPM) schemes. From the BER plots, we evaluate the minimum average received power required to achieve a desired BER for all three schemes for different channel conditions. Subsequently, minimum transmitter power requirement is evaluated for both uplink and downlink using the range equation. It is observed that presence of moderate, light and thin fog cause additional power requirement. Also, among the three schemes, M-PPM scheme requires the least transmitter power, followed by M-DPPM and OOK schemes. Further, it is seen that the transmitter diversity or multiple input single output technique reduces the uplink minimum transmitter power requirement, whereas for downlink aperture averaging and receiver diversity or single input multiple output techniques can achieve the same. The power requirement for uplink is 8–10 dB more as compared to downlink in presence of turbulence and various weather conditions.

On the capacity of MISO FSO systems over gamma-gamma and misalignment fading channels.

In this work, the ergodic capacity performance for multiple-input/single-output (MISO) free-space optical (FSO) communications system with equal gain combining (EGC) reception is analyzed over gamma-gamma and misalignment fading channels, which are modeled as statistically independent, but not necessarily identically distributed (i.n.i.d.). Novel and analytical closed-form ergodic capacity expression is obtained in terms of H-Fox function by using the well-known inequality between arithmetic and geometric mean of positive random variables (RV) in order to obtain an approximate closed-form expression of the distribution of the sum of M gamma-gamma with pointing errors variates. In addition, we present an asymptotic ergodic capacity expression at high signal-to-noise ratio (SNR) for the ergodic capacity of MISO FSO systems. It can be concluded that the use of MISO technique can significantly reduce the effect of the atmospheric turbulence as well as pointing errors and, hence, provide significant capacity gain over the direct path link (DL). The impact of pointing errors on the MISO FSO system is also analyzed, which only depends on the number of laser sources and pointing error parameters. Moreover, it can be also concluded that the ergodic capacity performance is dramatically reduced as a consequence of the severity of pointing error effects. Simulation results are further demonstrated to confirm the analytical results.

Nonlinear structural identification by the “Reverse Path” spectral method

When dealing with nonlinear dynamical systems, it is important to have efficient, accurate and reliable tools for estimating both the linear and nonlinear system parameters from measured data. An approach for nonlinear system identification widely studied in recent years is “Reverse Path”. This method is based on broad-band excitation and treats the nonlinear terms as feedback forces acting on an underlying linear system. Parameter estimation is performed in the frequency domain using conventional multiple-input–multiple-output or multiple-input–single-output techniques. This paper presents a generalized approach to apply the method of “Reverse Path” on continuous mechanical systems with multiple nonlinearities. The method requires few spectral calculations and is therefore suitable for use in iterative processes to locate and estimate structural nonlinearities. The proposed method is demonstrated in both simulations and experiments on continuous nonlinear mechanical structures. The results show that the method is effective on both simulated as well as experimental data.