With the large-scale construction of high-speed railway, the impact of its high speed on Orthogonal Frequency Division Multiplexing (OFDM) channel estimation has caused a wide range of concern. This paper studies the OFDM systems in high-speed railway environment and its channel estimation using least square (LS) method. In the simulations, we take into account Doppler frequency shift, antenna ...

The multiple input Multiple Output (MIMO) is a wireless technology that can offer high spectral efficiency, capacity gain and/or diversity gain. On the other hand, the Worldwide Interoperability for Microwave Access (WiMAX) is a promising wireless technology which delivers data at high rates covering larger area. To retrieve desired signals in such technologies, we need to incorporate appropria...

In situ measurements with visible and near-infrared spectroscopy (vis-NIR) provide an efficient way for acquiring soil information of paddy soils in the short time gap between the harvest and following rotation. The aim of this study was to evaluate its feasibility to predict a series of soil properties including organic matter (OM), organic carbon (OC), total nitrogen (TN), available nitrogen ...

The scaled total least square (STLS) problem, introduced by B.D. Rao in 1997, unifies both the total least square (TLS) and the least square (LS) problems. The STLS problems can be solved by the singular value decomposition (SVD). In this paper, we give a rank-revealing two-sided orthogonal decomposition method for solving the STLS problem. An error analysis is presented. Our numerical experime...

In this note we study a truncated additive normalization of the Banzhaf value. We are able to show that it corresponds to the Least Square nucleolus (LS-nucleolus), which was originally introduced as the solution of a constrained optimization problem (Ruiz et al., 1996). Thus, the main result provides an explicit expression that eases the computation and contributes to the understanding of the ...

The Least-Squares (LS) acoustic source location estimation technique is reported for the application in a wireless sensor network. The technique uses acoustic signal energy measurements taken at individual sensors of a wireless sensor network to estimate an acoustic source location. In this paper, an improved formulation of this localization problem, which clarifies the LS estimation errors, is...

A special pilot pattern across two OFDM symbols is devised for channel estimation in OFDM systems with IQ imbalance at receiver. Based on this pilot pattern, a high-efficiency time-domain (TD) least square (LS) channel estimator is proposed to suppress channel noise by a factor of N/(L+1) in comparison with the frequency-domain LS one in [1] where N and L+1 are the total number of subcarriers a...

Parametric estimation of signals, based on quantized data, is often carried out by means of least squares (LS) or averaging techniques. Such an approach often leads to optimal performance, resulting in almost unbiased estimators when the quantization error can approximately be modeled as an additive white Gaussian noise, or when other additive white Gaussian noise sources are larger than the qu...

In this paper, we present channel estimators for Long Term Evolution Advanced (LTE-A) fast fading channels. We show that the LTE-A Reference Signals (RS) structure— despite being designed for rather static scenarios—allows for accurate estimation performance even for higher speeds. We derive a Linear Minimum Mean Square Error (LMMSE) estimator and outline the restrictions that the LTE-A standar...

Secured opportunistic Medium Access Control (MAC) and complexity reduction in channel estimation are proposed in the Cross layer design Cognitive Radio Networks deploying the secured dynamic channel allocation from the endorsed channel reservation. Channel Endorsement and Transmission policy is deployed to optimize the free channel selection as well as channel utilization to cognitive radio use...