Non-Gaussian noise quadratic estimation for linear discrete-time
time-varying systems
Huihong Zhao
a,
n
, Chenghui Zhang
b
a
Clean Energy Research and Technology Promotion Center, Dezhou University, No. 566 University Rd. West, Dezhou 253023, PR China
b
School of Control Science and Engineering, Shandong University, 17923 Jingshi Road, Jinan 250061, PR China
article info
Article history:
Received 21 July 2015
Received in revised form
26 September 2015
Accepted 2 October 2015
Communicated by Ma Lifeng Ma
Available online 22 October 2015
Keywords:
Input noise quadratic polynomial estima-
tion
Kronecker algebra
Deconvolution filter
Fixed-lag smoother
abstract
This study deals with the input noise quadratic polynomial estimation problem for linear discrete-time
non-Gaussian systems. The design of the non-Gaussian noise quadratic deconvolution filter and fixed-lag
smoother is firstly converted into a linear estimation problem in a suitable second-order polynomial
extended system. By employing the Kronecker algebra rules, the stochastic characteristics of the aug-
mented noise in the augmented system are discussed. Then a solution to the non-Gaussian noise
quadratic estimator is obtained through applying the projection formula in Kalman filtering theory. In
addition, the stability is proved by constructing an equivalent state-space model with uncorrelated
noises. Finally, a numerical example is given to show the effectiveness of the proposed method.
& 2015 Elsevier B.V. All rights reserved.
1. Introduction
The input noise estimation (also known as deconvolution) has a
rich history and a wide range of applications in image restoration,
oil exploration, speech signal processing, fault detection and so on
[1–4]. The task of the deconvolution problem is to estimate the
intended unknown input noise of a system by utilizing the
obtainable outputs. For the first time, an optimal white noise
smoother with application to seismic data processing in oil
exploration was presented in [2]. Applying the polynomial
approach in frequency domain, the optimal deconvolution esti-
mator was derived based on spectral factorization in [5]. Later,
both input and measurement white noise estimators were
designed by using the modern time series analysis method in [6].
Recently, the deconvolution theory was successfully applied to the
multi-sensor linear discrete time systems [7,8] and the systems
with packet dropouts [9–11]. Note that the above results were
obtained based on the input Gaussian noise assumption, however,
in many important technical areas the input noise is non-Gaussian
(see for instance [12–14]). This is the motivation to develop a new
algorithm which permits us to find a satisfactory non-Gaussian
noise estimator for linear discrete-time time-varying systems.
The estimation problem for non-Gaussian systems has received
more and more attention and some fundamental results have been
developed, refer to [12,15] and the references therein. For linear
non-Gaussian systems, the conditional expectation giving the
minimum mean square error estimate is an infinite dimensional
problem, and its solution cannot be easily numerically computed
[15]. Although the Kalman filter is the best affine estimator for the
non-Gaussian case, its estimated accuracy is inadequate in some
cases. Note that the polynomial filtering algorithm [12,15], which
employ both the observations of the original system and their
Kronecker products, is more accurate than the classical Kalman
filter, while maintaining the characteristics of easy calculability
and recursivity. Therefore, an increasing number of authors have
focussed on the polynomial estimator design for the non-Gaussian
systems. The pioneer work can be traced back to the recursive
arbitrary-degree finite-memory polynomial estimator design via
the classical Kalman filtering theory [12]. Later, the result was
successfully extended to polynomial filter for stochastic bilinear
systems [16] and polynomial extended Kalman filter [17]. When
the state-space model was unknown, the fixed-point, fixed-
interval and fi
xed-lag smoothers from uncertain observations
were presented based on the covariance information of the pro-
cesses in [18]. Recently, this method was applied to the study of
multi-sensor information fusion quadratic filter for linear systems
with uncertain observations [19]. However, these works have a
limitation that the Non-Gaussian noise polynomial estimator was
not investigated.
Contents lists available at ScienceDirect
journal homepage: www.elsevier.com/locate/neucom
Neurocomputing
http://dx.doi.org/10.1016/j.neucom.2015.10.015
0925-2312/& 2015 Elsevier B.V. All rights reserved.
n
Corresponding author.
E-mail addresses: huihong1980@163.com (H. Zhao),
zchui@sdu.edu.cn (C. Zhang).
Neurocomputing 174 (2016) 921 – 927