One basic problem in business-cycle studies is how to deal with nonstationary time series. The market economy is an evolutionary system. Economic time series therefore contain stochastic components that are necessarily time dependent. Traditional methods of business cycle analysis, such as the correlation analysis and the spectral analysis, cannot capture such historical information because the...

Cardinality estimation schemes of Radio Frequency IDentification (RFID) tags using Framed Slotted ALOHA (FSA) based protocol are studied in this paper. Not as same as previous estimation schemes, we consider tag cardinality estimation problem under not only detection errors but also capture effect, where a tag’s IDentity (ID) might not be detected even in a singleton slot, while it might be ide...

most of the methods that have been proposed for speed estimation of induction machines require the rotor and the stator resistance to change in the normal operating range. on the other hand, estimation of the rotor resistance requires rotor speed. in this paper, after studying conditions for simultaneous estimation of rotor speed and rotor resistance, a method for simultaneous estimation of rot...

Estimating the frequency of a signal embedded in additive white Gaussian noise is one of the classical problems in signal processing. It is of fundamental importance in various applications such as in communications, Doppler radar, synthetic aperture radar (SAR), array processing, radio frequency identification (RFID), resonance sensor, etc. The requirement on the performance of the frequency e...

Ren et al. presented an efficient carrier frequency offset (CFO) estimation method for orthogonal frequency division multiplexing (OFDM), which has an estimation range as large as the bandwidth of the OFDM signal and achieves high accuracy without any constraint on the structure of the training sequence. However, its detection probability of the integer frequency offset (IFO) rapidly varies acc...

High performance frequency estimation is an important issue in orthogonal frequency division multiplexing (OFDM) systems since OFDM systems are very sensitive to carrier frequency offsets. Recently, Morelli & Mengali (M&M) [12] presented a near optimal frequency estimator based on the best linear unbiased estimation (BLUE) principle. In this paper, we have presented three frequency estimation m...

To track frequency offset and time-varying channel in orthogonal frequency division multiplexing (OFDM) systems over mobile wireless channels, a common technique is, based on one OFDM training block sample, to apply the maximum-likelihood (ML) algorithm to perform joint frequency tracking and channel estimation employing some adaptive iteration processes. The major drawback of such joint estima...

A complete OFDM synchronization chain is proposed based on practical synchronization schemes. The synchronization is accomplished in three steps: frame detection (or timing), frequency offset estimation, and phase tracking. For frame detection, time-domain differential PN sequence is used. For frequency offset estimation, time-domain correlation of adjacent pilot symbols estimates the fractiona...

This paper discusses the effects of frequency offset on the performance of orthogonal frequency division multiplexing (OFDM) digital communications. The main problem with frequency offset is that it introduces interference among the multiplicity of carriers in the OFDM signal. The aim of this survey is to investigate Carrier frequency offset estimation method in based OFDM systems. According to...

This letter investigates the non-coherent Direction of Arrival (DOA) estimation problem dealing with the DOA estimation from magnitude only measurements of the array output. The magnitude squared of the array output is expanded as a superposition of some harmonics. Hence, a frequency estimation approach is used to find some nonlinear relations between DOAs, which results in inherent ambiguities...