A Hybrid Approach to Joint Estimation of Channel and Antenna impedance

Wu, Shaohan; Hughes, B.L.

doi:10.1109/acssc.2018.8645068

Cited by 9 publications

(8 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where F is defined in (12) and Σ h in (10). Using the multi-packet sufficient statistics in (49), the multi-packet ML estimators for θ shall satisfy the following optimal criteria,…”

Section: Estimators For Multiple Packetsmentioning

confidence: 99%

Antenna Impedance Estimation at MIMO Receivers

Wu¹,

Hughes²

2022

Preprint

Self Cite

View full text Add to dashboard Cite

This paper considers antenna impedance estimation based on training sequences at MIMO receivers.The goal is to firstly leverage extensive resources available in most wireless systems for channel estimation to estimate antenna impedance in real-time. We assume the receiver switches its impedance in a predetermined fashion during each training sequence. Based on voltage observation across the load, a classical estimation framework is developed incorporating the Rayleigh fading assumption. We then derive in closed-form a maximum-likelihood (ML) estimator under i.i.d. fading and show this same ML estimator is a method of moments (MM) estimator in correlated channels. Numerical results suggest a fast algorithm, i.e., MLE in i.i.d. fading and the MM estimator in correlated fading, that estimates the unknown antenna impedance in real-time for all Rayleigh fading channels.

show abstract

“…where F is defined in (12) and Σ h in (10). Using the multi-packet sufficient statistics in (49), the multi-packet ML estimators for θ shall satisfy the following optimal criteria,…”

Section: Estimators For Multiple Packetsmentioning

confidence: 99%

Antenna Impedance Estimation at MIMO Receivers

Wu¹,

Hughes²

2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…It therefore suffices to derive estimators for h, F and σ 2 h . In our prequel, we proposed a hybrid approach to jointly estimate h and F for the special case N = 1 and σ 2 h known [12]. In this paper, we consider an alternative approach for N ≥ 1 and σ 2 h unknown, in which we solve this problem in two successive steps: First, we consider joint maximum-likelihood estimation of F and σ 2 h , treating h as a nuisance parameter.…”

Section: Antenna Loadmentioning

confidence: 99%

“…Recently, several studies have considered direct estimation of the receiver antenna impedance [9]- [12]. In [9], Ali et al propose an approach to measure the antenna impedance that compares the received signal power at different frequencies and different loads.…”

Section: Introductionmentioning

confidence: 99%

“…Finally, through numerical examples, we also investigate the impact the channel and impedance estimation error on the ergodic capacity and on the receiver signalto-noise ratio when used in conjunction with adaptive matching. In our previous works, joint channel and antenna impedance estimators of single-antenna receivers are derived in classical estimation [11] and hybrid settings [12]. However, neither of these two settings results in the optimal impedance estimator [14].…”

Section: Introductionmentioning

confidence: 99%

“…where B 1 , B 2 are defined in (12). For example, this can be achieved by using a normalized discrete Fourier transform (DFT) matrix [20, eq.…”

mentioning

confidence: 99%

See 2 more Smart Citations

PCA-based Antenna Impedance Estimation in Rayleigh Fading Channels

Wu¹,

Hughes²

2020

Preprint

Self Cite

View full text Add to dashboard Cite

Impedance matching between receive antenna and front-end significantly impacts channel capacity in wireless channels. To implement capacity-optimal matching, the receiver must know the antenna impedance. But oftentimes this impedance varies with loading conditions in the antenna near-field. To mitigate this variation, several authors have proposed antenna impedance estimation techniques. However, the optimality of these techniques remains unclear. In this paper, we consider antenna impedance estimation at MISO receivers over correlated Rayleigh fading channels. We derive in closed-form the optimal ML estimator under i.i.d. fading and then show it can be found via a scalar optimization in generally correlated fading channels. Numerical results suggest a computationally efficient, principalcomponents approach that estimates antenna impedance in real-time for all Rayleigh fading channels. Furthermore, ergodic capacity can be significantly boosted at originally poorly matched receivers with adaptive matching using our proposed approach.

show abstract

A unified scheme to solving arbitrary complex-valued ratio distribution with application to statistical inference for raw frequency response functions and transmissibility functions

Yan

Zhao

Beer

et al. 2020

Mechanical Systems and Signal Processing

View full text Add to dashboard Cite

Complex-valued ratio distributions arise in many scientific and engineering domains such as statistical inference for frequency response functions (FRFs) and transmissibility functions (TFs) in structural health monitoring. When solving the distribution properties for complex ratio random variables through the definition of probability density function (PDF), the problem is usually accompanied by complicated derivatives. In this study, a unified scheme to solve complex ratio random variables is proposed for the case when it is highly non-trivial or impossible to discover a closed-form solution, such as for complex-valued t ratio distributions. Based on the probability transformation principle in the complex domain, a unified formula is derived by reducing the concerned problem into multidimensional integrals, which can be solved by advanced numerical techniques. A fast Sparse-Grid Quadrature (SGQ) rule by constructing multivariate quadrature formulas using the combinations of tensor products of suitable one-dimensional formulas is utilized to improve the computational efficiency by avoiding the curse of integral dimensionality. The unified methodology can efficiently calculate the PDF of a ratio random variable with its denominator and nominator specified by arbitrary probability distributions including Gaussian or non-Gaussian ones, correlated or independent random variables, as well as bounded or unbounded ratio random variables. The unified scheme 2 is applied to uncertainty quantification for FRFs and TFs, and the efficiency of the proposed scheme is verified by using the vibration testing field data conducted on a simply-supported beam, as well as onAlamosa Canyon Bridge.

show abstract

A Hybrid Approach to Joint Estimation of Channel and Antenna impedance

Cited by 9 publications

References 17 publications

Antenna Impedance Estimation at MIMO Receivers

Antenna Impedance Estimation at MIMO Receivers

PCA-based Antenna Impedance Estimation in Rayleigh Fading Channels

A unified scheme to solving arbitrary complex-valued ratio distribution with application to statistical inference for raw frequency response functions and transmissibility functions

Contact Info

Product

Resources

About