This paper presents a combined approach to channel estimation for multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM). It uses both time domain and frequency domain information in the received signal to estimate the channel. Initial estimate of the channel is obtained using pilot assisted least square (LS) channel estimation. The estimate is further enhanced ...

We present an iterative channel estimation and decoding scheme for a coded system through multi-input multioutput (MIMO) Rayleigh block fading channels in spatially correlated noise. An expectation-maximization (EM) algorithm is utilized to find the maximum likelihood (ML) estimates of the channel and the spatial noise covariance matrix, based on which the soft information of coded symbols is c...

In this study, we study compressive channel estimation for Orthogonal Frequency Division Multiplexing (OFDM) modulated Amplify-and-Forward (AF) relay networks. Based upon the mathematical channel model of P2P and sparseness measure function, by using Monte-Carlo runs, we show that the OFDM cooperation convoluted channels also exhibit sparsity. In this study, we propose two compressive channel e...

In this paper, an adaptive channel estimation scheme based on the reduced-rank (RR) Wiener filtering (WF) technique is proposed for multi-band (MB) orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) communication systems in multipath fading channels. This RR-WF-based algorithm employs an adaptive fuzzy-inference-controlled (FIC) filter rank. Additionally, a comparative inves...

In this study, compressed channel estimation method for sparse multipath two-way relay networks is investigated. Conventional estimation methods, e.g., Least Square (LS) and Minimum Mean Square Error (MMSE), are based on the dense assumption of relay channel and cannot exploit channel sparsity which has been verified by lots of channel measurements. Unlike the previous methods, we propose a com...

Initial estimation is a considerable issue in channel estimation techniques, since all of the following processes depends on it, which in this paper its improvement is discussed. Least Square (LS) method is a common simple way to estimate a channel initially but its efficiency is not as significant as more complex approaches. It is possible to enhance channel estimation performance by using som...

Channel estimation is a key technology for wireless optical communication (WOC) systems. Based on the training sequence (TS), this article develops three frequency domain (FD) channel estimation approaches for diffuse wireless optical channels. Considering the propagation property of light and the characteristics of optical modulation, this article establishes a link model for the indoor WOC sy...

The main objective of this paper, is to review the work already done related to channel estimation technique in OFDM system. Pilot base channel estimation algorithm i.e. block type, comb type etc. are discussed and also compared in terms of their simplicity, computational cost and suitability conditions. After comparison with known techniques i.e. decision directed-Kalmanbased estimation, Maxim...

© 2015 Rugui Yao et al. 11 http://dx.doi.org/10.4218/etrij.15.0114.0758 This paper deals with optimal power allocation for channel estimation of orthogonal frequency-division multiplexing uplinks in time-varying channels. In the existing literature, the estimation of time-varying channel response in an uplink environment can be accomplished by estimating the corresponding channel parameters. Ac...