SISO Configuration Research Articles

Photovoltaic Power Generation Forecasting with Hidden Markov Model and Long Short-Term Memory in MISO and SISO Configurations

Photovoltaic (PV) power generation forecasting is an important research topic, aiming to mitigate variability caused by weather conditions and improve power generation planning. Climate factors, including solar irradiance, temperature, and cloud cover, influence the energy conversion achieved by PV systems. Long-term weather forecasting improves PV power generation planning, while short-term forecasting enhances control methods, such as managing ramp rates. The stochastic nature of weather variables poses a challenge for linear regression methods. Consequently, advanced, state-of-the-art machine learning (ML) approaches capable of handling non-linear data, such as long short-term memory (LSTM), have emerged. This paper introduces the implementation of a multivariate machine learning model to forecast PV power generation, considering multiple weather variables. A deep learning solution was implemented to analyze weather variables in a short time horizon. Utilizing a hidden Markov model for data preprocessing, an LSTM model was trained using the Alice Spring dataset provided by DKA Solar Center. The proposed workflow demonstrated superior performance compared to the results obtained by state-of-the-art methods, including support vector machine, radiation classification coordinate with LSTM (RCC-LSTM), and ESNCNN specifically concerning the proposed multi-input single-output LSTM model. This improvement is attributed to incorporating input features such as active power, temperature, humidity, horizontal and diffuse irradiance, and wind direction, with active power serving as the output variable. The proposed workflow achieved a mean square error (MSE) of 2.17×10−7, a root mean square error (RMSE) of 4.65×10−4, and a mean absolute error (MAE) of 4.04×10−4.

Analysis of Antenna Locations (Roof, Fender, and Bumper) at 28 GHz in a Suburban Environment for V2I using SISO and MIMO Antenna Configurations

Analysis of Antenna Locations (Roof, Fender, and Bumper) at 28 GHz in a Suburban Environment for V2I using SISO and MIMO Antenna Configurations

Lyapunov-Based Nonlinear Control Applied to a Control Moment Gyroscope

One of the main applications of a mechanical control moment gyroscope (CMG) as actuator is the attitude control of spacecraft and satellites, which requires a wide operating range. Motivated by this, this paper investigates the feasibility of a Lyapunov-based nonlinear control applied to the tracking task of a CMG unit from Educational Control Products, model 750, in its SISO configuration. This problem involves an underactuated system, in which the output signal is the unactuated state, posing additional challenges to control design. To deal with it, an additional internal control signal is employed and the stability analysis of the closed-loop system is given by invoking both Lyapunov stability and Matrosov’s theorem. To validate the proposed controller, numerical simulations and practical experiments were performed and contrasted with the authors’ previous designed nonlinear controllers.

Performance of MIMO-OFDM Systems

Orthogonal frequency division multiplexing (OFDM) is one of the new modulation techniques which is used to combat the frequency-selectivity of the transmission channel models achieving high data rate without inter-symbol interference. OFDM may be combined with antenna arrays at the transmitter and receiver to increase the system capacity on time-variant and frequency-selective channel models resulting in a multiple-input multiple-output (MIMO) configuration. In this paper, SISO, SIMO, MISO and MIMO-OFDM configurations of OFDM systems are proposed. LS channel estimator is used to calculate the channel coefficients. The four different OFDM systems are analysed and simulated. The simulation consists of four parameters namely bit error rate, mean square error, symbol error rate and capacity of the channel for MIMO-OFDM systems. The error rate values are minimised in 2×2 MIMO-OFDM systems compared to other 1×1, 1×2, 2×1 OFDM systems. Similarly channel capacity is maximised in 2×2 MIMO-OFDM systems, compared to the other OFDM systems. These performances are implemented using MATLAB software.

Realization of LTE physical layer baseband processing architecture for narrowband IOT

The 3GPP Long Term Evolution represents the major innovation in cellular technology. NB-IoT is the 3GPP standard for machine to machine communication finalized within LTE Release13. NB-IoT technology occupies frequency band of 180 kHz bandwidth which corresponds to one resource block in LTE transmission. The Long Term Evolution (LTE) supports higher data rates, higher bandwidth, Low latency, good Quality of Service whereas objective of Narrow Band Internet of Things (NB - IOT) is to achieve extended coverage, to support massive number of smart devices and have multi - year long battery life. So the main focus is linking LTE with IOT. The objective of this paper proposes transmitter architecture of PUCCH (Physical Uplink Control Channel) and PUSCH(Physical uplink Shared Channel) in SISO and SIMO configurations for physical uplink channels of LTE. The physical uplink and downlink channel processing involves scrambling, modulation, layer mapping, transform precoding, and resource element mapping at the transmitter and the receiver block to have demapping from the resource elements and detection of data. At present, the data for on-off control has been worked and the whole framework has been simulated using Modelsim and implemented in Spartan 6.

Experimental investigation of inter-core crosstalk tolerance of MIMO-OFDM/OQAM radio over multicore fiber system.

In this paper, the feasibility of space division multiplexing for optical wireless fronthaul systems is experimentally demonstrated by implementing high speed MIMO-OFDM/OQAM radio signals over 20km 7-core fiber and 0.4m wireless link. Moreover, the impact of optical inter-core crosstalk in multicore fibers on the proposed MIMO-OFDM/OQAM radio over fiber system is experimentally evaluated in both SISO and MIMO configurations for comparison. The experimental results show that the inter-core crosstalk tolerance of the proposed radio over fiber system can be relaxed to -10 dB by using the proposed MIMO-OFDM/OQAM processing. These results could guide high density multicore fiber design to support a large number of antenna modules and a higher density of radio-access points for potential applications in 5G cellular system.

On the Suitability of Multicore Fiber for LTE–Advanced MIMO Optical Fronthaul Systems

This paper proposes and evaluates analytically and experimentally the suitability of spatial multiplexing in multicore fiber (MCF) for multiple-input multiple-output (MIMO) LTE–Advanced (LTE–A) optical fronthaul systems including carrier aggregation. The experimental test-bed comprises a 150-m optical fronthaul of four-core homogeneous MCF, which can be configured with different bending radius for analysis. Performance of linear crosstalk in MCF media is evaluated by simulation and validated by the experimental work in the laboratory with the radio-over-fiber transmission of full-standard LTE–A wireless signals considering both SISO and MIMO configurations. The optical fronthaul analysis evaluates both same-propagation and counter-propagation spatial multiplexing, i.e., all cores propagating in the same direction and two versus two cores propagating in opposite directions, corresponding to a dual LTE–A roof-mounted system. The performance of the MCF optical fronthaul system is evaluated using a single 20–MHz LTE–A carrier and also carrier-aggregated signals with 16QAM and 64QAM subcarrier modulation. The experimental results indicate that intercore crosstalk (IC–XT) increases up to 9.6 dB when raising the bending radius from 35 to 67 cm, being the bending radius a key parameter in MCF fronthaul systems. The demonstration performed at 1550.12 nm reported an increase of IC–XT of 4.6 dB with the bending radius, which deteriorates the quality of the SISO LTE–A signal up to 8.1 dB error vector magnitude (EVM). This IC–XT impairment can be mitigated using 2×2 MIMO processing, which reduces the EVM impact to less than 1 dB when increasing the MCF bending radius from 35 to 67 cm. The experimental results indicate that 3GPP MIMO LTE–A algorithms already in-place in the wireless LTE–A standard can be used to compensate the IC–XT in the 150-m multicore optical fronthaul system with spatial multiplexing.

A systematic and flexible approach for testing future mobile networks by exploiting a wrap-around testing methodology

The testing process of state-of-the-art telecommunication equipment is a demanding task requiring multiple testing phases and significant amounts of resources. This article introduces a testing concept that enables the same testing environment to be used throughout the development lifecycle of telecommunication equipment. Moreover, the testing approach is designed to exploit the salient features of the upcoming IMT-Advanced systems in order to make the testing process more efficient. At the heart of the this wrap-around testing approach are a few multi-purpose network and radio channel emulators which can be configured to support all the testing phases from unit testing to system testing. By utilizing the same testing tools in all the testing phases, the amount of resources required for test environment maintenance and testing tool training are minimized. In addition, the extensive use of simulations makes the testing environment very flexible when it comes to studying the new features of the most recent telecommunication standards. In order to verify the feasibility of the devised testing approach, this article also contains a case study example, in which an implementation of the wrap-around testing environment is built from commercial testing tools. In the presented case study, the testing environment implementation is used for throughput testing of an LTE eNB in SISO and MIMO configurations. The results obtained are compared to the theoretical performance values of the technology and, together with earlier studies, demonstrate that a testing environment based on the wrap-around testing concept can be used in different testing phases during LTE eNB development.