Blind equalisation algorithm of FIR MIMO system in frequency domain

2006 ◽  
Vol 153 (5) ◽  
pp. 703 ◽  
Author(s):  
X. Shen ◽  
H. Xu ◽  
F. Cong ◽  
J. Lei ◽  
K. Huang ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Mimo System

Behavioral modeling and digital pre-distortion techniques for RF PAs in a 3 × 3 MIMO system

2019 ◽  
Vol 11 (10) ◽  
pp. 989-999 ◽  
Author(s):  
Mahmoud Alizadeh ◽  
Peter Händel ◽  
Daniel Rönnow
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Mimo Systems ◽  
Mimo System ◽  
Parameters Estimation ◽  
Behavioral Modeling ◽  
Type Model ◽  
Rf Power Amplifiers ◽  
Model Errors ◽  
Frequency Domains

AbstractModern telecommunications are moving towards (massive) multi-input multi-output (MIMO) systems in 5th generation (5G) technology, increasing the dimensionality of the systems dramatically. In this paper, the impairments of radio frequency (RF) power amplifiers (PAs) in a 3 × 3 MIMO system are compensated in both the time and the frequency domains. A three-dimensional (3D) time-domain memory polynomial-type model is proposed as an extension of conventional 2D models. Furthermore, a 3D frequency-domain technique is formulated based on the proposed time-domain model to reduce the dimensionality of the model, while preserving the performance in terms of model errors. In the 3D frequency-domain technique, the bandwidth of the system is split into several narrow sub-bands, and the parameters of the model are estimated for each sub-band. This approach requires less computational complexity, and also the procedure of the parameters estimation for each sub-band can be implemented independently. The device-under-test consists of three RF PAs including input and output cross-talk channels. The proposed techniques are evaluated in both behavioral modeling and digital pre-distortion (DPD) perspectives. The experimental results show that the proposed DPD technique can compensate the errors of non-linearity and memory effects in the both time and frequency domains.

scholarly journals Complex-Coefficient Frequency Domain Stability Analysis Method for a Class of Cross-Coupled Antisymmetrical Systems and Its Extension in MSR Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Yuan Ren ◽  
Jiancheng Fang
Keyword(s):  
Stability Analysis ◽  
Frequency Domain ◽  
Stability Criterion ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Complex Coefficient ◽  
Analysis Method ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Domain Stability

This paper develops a complex-coefficient frequency domain stability analysis method for a class of cross-coupled two-dimensional antisymmetrical systems, which can greatly simplify the stability analysis of the multiple-input multiple-output (MIMO) system. Through variable reconstruction, the multiple-input multiple-output (MIMO) system is converted into a single-input single-output (SISO) system with complex coefficients. The pole locations law of the closed-loop system after the variable reconstruction has been revealed, and the controllability as well as observability of the controlled plants before and after the variable reconstruction has been studied too, and then the classical Nyquist stability criterion is extended to the complex-coefficient frequency domain. Combined with the rigid magnetically suspended rotor (MSR) system with heavy gyroscopic effects, corresponding stability criterion has been further developed. Compared with the existing methods, the developed criterion for the rigid MSR system not only accurately predicts the absolute stability of the different whirling modes, but also directly demonstrates their relative stability, which greatly simplifies the analysis, design, and debugging of the control system.

Study on Dual-Loop Controller of Helicopter Based on the Robust H-Infinite Loop Shaping Method

2011 ◽  
Vol 130-134 ◽  
pp. 1182-1185 ◽  
Author(s):  
Zhe Yan Lang ◽  
Ai Guo Wu
Keyword(s):  
Frequency Domain ◽  
Simple Structure ◽  
Mimo System ◽  
Prototype Model ◽  
Design Requirement ◽  
Internal Loop ◽  
External Loop ◽  
Loop Shaping ◽  
Infinite Loop ◽  
Simulation Results

Helicopter is a typical MIMO system including the properties of non-stability, strong coupling, uncertainty. Firstly, a robust internal loop ACAH controller is designed and analyzed to ensure decoupling and robustness on each channel by the robust H-infinite loop shaping. Secondly, the external loop is designed using the classical PID method on the base of decoupling internal loop. Both loops contain the part of anti-windup. The simulation results of the prototype model demonstrate that in both time and frequency domain, the performance of the controller meets the design requirement with a comparative simple structure. The results can also prove that it has some effect against to the model perturbation and achieve LEVEL1 of ADS-33E-PRF.

A frequency domain-based approach for blind MIMO system identification using second-order cyclic statistics

2009 ◽  
Vol 89 (1) ◽  
pp. 77-86 ◽  
Author(s):  
K. Sabri ◽  
M. El Badaoui ◽  
F. Guillet ◽  
A. Adib ◽  
D. Aboutajdine
Keyword(s):  
System Identification ◽  
Frequency Domain ◽  
Mimo System ◽  
Second Order ◽  
Cyclic Statistics

Improvement of the envelope – transient S-parameters' simulation in circuit and system simulation

2011 ◽  
Vol 3 (6) ◽  
pp. 657-665
Author(s):  
Hassan Mehdi ◽  
Sebastien Mons ◽  
Abderrazak Bennadji ◽  
Edouard Ngoya ◽  
Raymond Quere
Keyword(s):  
Frequency Domain ◽  
Mimo Systems ◽  
Mimo System ◽  
System Simulation ◽  
Control Flow ◽  
Behavioral Modeling ◽  
System Level ◽  
Synthesis Process ◽  
S Parameters ◽  
High Level

This paper focuses on the behavioral modeling of the passive RF blocks from frequency-domain samples. This work is based on vector fitting (VF) approach which is a robust method for MIMO system identification in the frequency domain. This paper addresses firstly the problem of convergence using envelope transient (ET) on complex circuits, i.e. power amplifiers (PAs), where linear sub-circuits are widely described through S-parameters matrices derived from ElectroMagnetic (EM) simulations. An alternative way leads to combine VF method with an RLC synthesis process at the circuit level. This approach is validated on a simple circuit case and generalized to MIMO systems. Second application is the behavioral modeling of MIMO blocks at system level in a high-level spice-like system simulation tool which allows “Control Flow” simulations. The proposed approach combines on one hand the VF method with and impulse responses evaluation on the other hand. In consequence, bilateral behavioral models of MIMO system can be efficiently achieved irrespective of the number of access. This method is validated at once on simple and complex MIMO blocks. As a result, the topological behavioral modeling of complex PAs, which distinguish linear sub-circuits and nonlinear ones, is now possible in a high-level time-domain CAD tool.

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