A FRACTIONAL ORDER UNIVERSAL HIGH GAIN ADAPTIVE STABILIZER

2012 ◽  
Vol 22 (04) ◽  
pp. 1250081 ◽  
Author(s):  
YAN LI ◽  
YANGQUAN CHEN
Keyword(s):  
Fractional Order ◽  
Mimo Systems ◽  
Adaptive Strategy ◽  
High Gain ◽  
Control Effort ◽  
Single Output ◽  
Control Gain ◽  
Multiple Input ◽  
Finite Control ◽  
Adaptive Stabilizer

In this paper, a fractional order universal high gain adaptive stabilizer is proposed which guarantees the Lp stability of fractional order multiple–input and multiple–output (MIMO) systems with finite control effort. The boundedness of the control gain for the fractional order universal adaptive strategy is discussed for fractional order MIMO systems, and an upper bound of the control gain is presented for fractional order single-input and single-output (SISO) systems. Some advantages of the discussed fractional order universal adaptive stabilizer are demonstrated in numerical simulations, such as the overshoots of system outputs can be efficiently reduced by decreasing the fractional order of the universal adaptive stabilizer without significantly increasing the system gains.

Fractional Order Universal Adaptive Stabilizer for Fractional Order Systems

2009 ◽  
Author(s):  
Yan Li ◽  
YangQuan Chen
Keyword(s):  
Fractional Order ◽  
Order System ◽  
Adaptive Stabilization ◽  
Space System ◽  
Control Effort ◽  
Finite Control ◽  
State Space System ◽  
Adaptive Stabilizer ◽  
Fractional Controller ◽  
Order State

In this paper, the fractional order universal adaptive stabilization of fractional order SISO system is discussed. The fractional universal adaptive stabilizer is u(t) = −k(t)sgn{CB}y(t), where 0Dtβk(t) = ‖y(t)‖p, which guarantees the asymptotic stability of the equilibrium point of fractional order state space system with finite control effort. Moreover, the fractional order system with order α ∈ (0, 1/(1+p)) can be stabilized by the fractional controller but not for the integer order controller. Simulation results are provided as the proof of concepts.

scholarly journals Space-Time-Color (STC) Scheme with Symbol-Hopping for Color Shift Keying (CSK)Modulation

2021 ◽  
Author(s):  
Leandro Ximenes ◽  
Rangel Arthur ◽  
igor Santos Cruz Rodrigues
Keyword(s):  
Mimo Systems ◽  
Communication Link ◽  
Visible Light Communications ◽  
Single Output ◽  
Multiple Input ◽  
Shift Keying ◽  
Single Input ◽  
Diversity Gains ◽  
Csk Constellation ◽  
Siso Systems

<div>This paper proposes a novel coding scheme for Visible Light Communications (VLC) systems using symbol mapping permutations on the color domain. The permutation is done through symbol-hopping over the points of an optimized 4-CSK constellation. This scheme provides diversity gains, promises robustness against monochromatic channel degradation, and increases the information security of the communication link. It can also be used in conjunction with Single-Input and Single-Output (SISO) systems, as well as in Multiple-Input and Multiple-Output (MIMO) systems. Monte Carlo computational simulations evaluate the performance of the proposed scheme over the conventional QuadLED (QLED) CSK system and other codes, showing superior coding and diversity gains over two direct competitors, under a Rician flat-fading channel.</div>

scholarly journals Optimized Scheduling Technique of Null Subcarriers for Peak Power Control in 3GPP LTE Downlink

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Soobum Cho ◽  
Sang Kyu Park
Keyword(s):  
Power Efficiency ◽  
Multiple Access ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Average Power ◽  
Papr Reduction ◽  
Single Input Single Output ◽  
Single Output ◽  
Multiple Input ◽  
Input Multiple Output

Orthogonal frequency division multiple access (OFDMA) is a key multiple access technique for the long term evolution (LTE) downlink. However, high peak-to-average power ratio (PAPR) can cause the degradation of power efficiency. The well-known PAPR reduction technique, dummy sequence insertion (DSI), can be a realistic solution because of its structural simplicity. However, the large usage of subcarriers for the dummy sequences may decrease the transmitted data rate in the DSI scheme. In this paper, a novel DSI scheme is applied to the LTE system. Firstly, we obtain the null subcarriers in single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems, respectively; then, optimized dummy sequences are inserted into the obtained null subcarrier. Simulation results show that Walsh-Hadamard transform (WHT) sequence is the best for the dummy sequence and the ratio of 16 to 20 for the WHT and randomly generated sequences has the maximum PAPR reduction performance. The number of near optimal iteration is derived to prevent exhausted iterations. It is also shown that there is no bit error rate (BER) degradation with the proposed technique in LTE downlink system.

scholarly journals Space-Time-Color (STC) Scheme with Symbol-Hopping for Color Shift Keying (CSK)Modulation

2021 ◽  
Author(s):  
Leandro Ximenes ◽  
Rangel Arthur ◽  
igor Santos Cruz Rodrigues
Keyword(s):  
Mimo Systems ◽  
Communication Link ◽  
Visible Light Communications ◽  
Single Output ◽  
Multiple Input ◽  
Shift Keying ◽  
Single Input ◽  
Diversity Gains ◽  
Csk Constellation ◽  
Siso Systems

<div>This paper proposes a novel coding scheme for Visible Light Communications (VLC) systems using symbol mapping permutations on the color domain. The permutation is done through symbol-hopping over the points of an optimized 4-CSK constellation. This scheme provides diversity gains, promises robustness against monochromatic channel degradation, and increases the information security of the communication link. It can also be used in conjunction with Single-Input and Single-Output (SISO) systems, as well as in Multiple-Input and Multiple-Output (MIMO) systems. Monte Carlo computational simulations evaluate the performance of the proposed scheme over the conventional QuadLED (QLED) CSK system and other codes, showing superior coding and diversity gains over two direct competitors, under a Rician flat-fading channel.</div>

scholarly journals A Survey of Fractional Order Calculus Applications of Multiple-Input, Multiple-Output (MIMO) Process Control

2020 ◽  
Vol 4 (2) ◽  
pp. 22
Author(s):  
Alexandre Marques de Almeida ◽  
Marcelo Kaminski Lenzi ◽  
Ervin Kaminski Lenzi
Keyword(s):  
Fractional Order ◽  
Systems Engineering ◽  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Systems Control ◽  
Fractional Control ◽  
Siso Systems

Multiple-input multiple-output (MIMO) systems are usually present in process systems engineering. Due to the interaction among the variables and loops in the MIMO system, designing efficient control systems for both servo and regulatory scenarios remains a challenging task. The literature reports the use of several techniques mainly based on classical approaches, such as the proportional-integral-derivative (PID) controller, for single-input single-output (SISO) systems control. Furthermore, control system design approaches based on derivatives and integrals of non-integer order, also known as fractional control or fractional order (FO) control, are frequently used for SISO systems control. A natural consequence, already reported in the literature, is the application of these techniques to MIMO systems to address some inherent issues. Therefore, this work discusses the state-of-the-art of fractional control applied to MIMO systems. It outlines different types of applications, fractional controllers, controller tuning rules, experimental validation, software, and appropriate loop decoupling techniques, leading to literature gaps and research opportunities. The span of publications explored in this survey ranged from the years 1997 to 2019.

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