In this paper to improve the channel estimation accuracy in OFDM system , channel state information is required for signal detection at receiver and its accuracy affects the overall performance of system and it is essential to improve the channel estimation for more reliable communications. This paper addresses channel estimation based on time-domain channel statistics, using a general model LS...

MIMO-OFDM (multiple input multiple output-orthogonal frequency division multiplexing) is an excellent technique used in modern wireless communication systems. It has excellent quality of high speed data/voice transmission with high spectral efficiency. The Least Square (LS) and Minimum Mean Square Error (MMSE) channel estimation are the most common methods presented by several researchers. Disc...

The Channel estimation is one of the fundamental issues of OFDM system design. Techniques that are used for channel estimation of OFDM system are least-square (LS) and minimum-mean-square-error (MMSE) techniques. The LS Estimator algorithm is very simple, but it may be subject to noise enhancement, so the performance is worse. The MMSE Estimator gives better performance than LS and MSE is minim...

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...

A multiple-input multiple-output (MIMO) communication system combined with the orthogonal frequency division multiplexing (OFDM) modulation technique can achieve reliable high data rate transmission over broadband wireless channels. Channel state information for both single-input single-output (SISO) and MIMO systems based on pilot aided arrangement is investigated in this paper. The estimation...

Abstract Gravity recovery and climate experiment (GRACE) GRACE Follow-On (GRACE-FO) are Earth’s gravity satellite missions with hydrological monitoring applications. However, caused by measuring instrumental problems, there several temporal missing values in the dataset of two where a long gap between mission also exists. Recent studies utilized different gap-filling methodologies to fill those...

During the last few years, the progress in wireless communication is widely increasing to mitigate the ever increasing demand of higher data rates. OFDM (Orthogonal Frequency Division Multiplexing) techniques using more densely packed carriers, thus achieving higher data rates using similar channels. In this paper, the estimation is based on the minimum mean square error (MMSE) estimator and th...

Multipath channels often exhibit sparse structures in multicarrier underwater acoustic (MC-UWA) communication systems. Conventional linear channel estimators, such as least squares (LS) and minimum mean square error (MMSE) are considered as optimal solutions under the assumption of rich multipath. However, they often result in low spectral efficiency due to neglect of the sparsity in multipath ...

This paper presents channel estimation techniques for demodulate and forward (DeF) wireless relay networks (WRN) using least squares (LS) algorithm and its variants. Channel estimation is a significant issue in wireless relay networks as it plays a major role in data detection of coherent communication systems. Channel coefficients (or) channel state information (CSI) need to be estimated by al...

Orthogonal Frequency Division Multiplexing (OFDM) is being used by the modern communication systems due to the increase in demand for high throughput wireless communication systems. OFDM has highly efficient spectrum usage and robustness to multipath fading channel impairments. The focus of the paper is to improve Discrete Fourier Transform (DFT)based channel estimator designed over a slow fadi...