Single-input Single-output Techniques Research Articles

Underwater wireless optical communication utilizing multiple input–multiple output (MIMO)-LED system for RF transmission with solar panel receiver

Abstract In this article, we designed an experimental system for underwater wireless optical communications. A function generation device sent frequencies (1–500 kHz) by amplitude shift key modulation technology, and these frequencies were loaded over light-emitting diode to propagate through a glass water tank with a length of 1 m, width of 40 cm, and height of 30 cm containing clean water of 80 L. These frequencies were received by a photodiode (BPX61), and the received signal was displayed through a digital storage oscilloscope device. Four techniques, single input–single output (SISO), single input–multiple output, multiple input–single output, and multiple input–multiple output (MIMO), were applied under the same optical conditions to know the quality of receiving the optical signal and the difference between them. Finally, the parameter values of signal-to-noise ratio, peak-to-peak voltage, and voltage gain were checked for each technique, and they were the lowest values for the SISO technique and the highest values for the MIMO technique.

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.

Quantitative Feedback Theory design of valve position control for co-ordinated superheater control of main steam temperatures of power plant boilers

Abstract This paper presents an application of a Single-Input Single-Output (SISO) controller and a Valve Position Controller (VPC) using robust Proportional-Integral (PI) controllers designed using Quantitative Feedback Theory (QFT) specifications to control superheater outlet steam temperatures of a 600MW once-through boiler. To illustrate the methodology, a dynamic model of a tower-type boiler was modelled using Flownex® to test the VPC design application with structured uncertainty under varying load and disturbance conditions. The results show that the valve position controller application is more efficient than the SISO technique, allowing the final attemperator more bandwidth to deal with unexpected temperature changes.

Cyclostationary Noise Mitigation for SIMO Powerline Communications

The cyclostationary noise in low-voltage narrowband powerline communications (NB-PLC) severely degrades the communication reliability. In this paper, we adopt single-input multi-output (SIMO) transmission to enhance the reliability of NB-PLC. Considering the SIMO receiver structure, we exploit the NB-PLC noise cyclostationarity and the high spatial correlations across multiple receive phases to design practical and efficient noise mitigation techniques. In particular, we propose two time-domain frequency-shift (FRESH) filtering-based cyclostationary signal recovery techniques with different performance and complexity levels. The proposed time-domain-based FRESH filtering techniques minimize the mean-squared error in estimating the orthogonal frequency division multiplexing (OFDM) information signal in the time-domain. The FRESH filtering exploits the cyclic auto-correlation of both the NB-PLC noise and the OFDM information signal in addition to their cyclic cross-correlation across the receive phases. Moreover, we propose a frequency-domain-based cyclostationary noise mitigation technique that minimizes the mean-squared error in estimating the OFDM information signal in the frequency-domain. The proposed frequency-domain-based technique exploits the cyclostationarity of the noise to estimate its power spectral density as well as the cross-correlation, per frequency subchannel, over multiple stationary noise temporal regions. Our proposed SIMO NB-PLC noise mitigation techniques are shown via simulation results conducted using noise field measurements to achieve considerable performance gains over single-input single-output techniques. In addition, we show that our proposed techniques achieve considerable performance gains over the conventional SIMO maximal-ratio-combiner designed assuming stationary noise.

A DC–DC Multiport-Converter-Based Solid-State Transformer Integrating Distributed Generation and Storage

The Solid-state transformer (SST) has been proposed by researchers to replace the regular distribution transformer in the future smart grid. The SST provides ports for the integration of storage and distributed generation (DG), e.g., photovoltaic (PV), and enables the implementation of power quality features. This paper proposes a SST topology based on a quad-active-bridge (QAB) converter which not only provides isolation for the load, but also for DG and storage. A gyrator-based average model is developed for a general multiactive-bridge (MAB) converter, and expressions to determine the power rating of the MAB ports are derived. These results are then applied to analyze the QAB converter. For the control of the dc-dc stage of the proposed QAB-based SST integrating PV and battery, a technique that accounts for the cross-coupling characteristics of the QAB converter in order to improve the regulation of the high-voltage-dc link is introduced. This is done by transferring the disturbances onto the battery. The control loops are designed using single-input single-output techniques with different bandwidths. The dynamic performance of the control strategy is verified through extensive simulation and experimental results.