scholarly journals Pseudorange error analysis for precise indoor positioning system

2017 ◽  
Vol 68 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Marek Pola ◽  
Pavel Bezoušek
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Estimation Method ◽  
Correlation Method ◽  
Signal Propagation ◽  
Ultra Wideband ◽  
Estimation Accuracy ◽  
Time Of Arrival ◽  
Position Measurement ◽  
Direct Path ◽  
Signal Time

Abstract There is a currently developed system of a transmitter indoor localization intended for fire fighters or members of rescue corps. In this system the transmitter of an ultra-wideband orthogonal frequency-division multiplexing signal position is determined by the time difference of arrival method. The position measurement accuracy highly depends on the directpath signal time of arrival estimation accuracy which is degraded by severe multipath in complicated environments such as buildings. The aim of this article is to assess errors in the direct-path signal time of arrival determination caused by multipath signal propagation and noise. Two methods of the direct-path signal time of arrival estimation are compared here: the cross correlation method and the spectral estimation method.

scholarly journals Complexity Effective Sampling Frequency Offset Estimation Method for OFDM-Based HomePlug Green PHY Systems

Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 544
Author(s):  
Yong-An Jung ◽  
Young-Hwan You
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Estimation Method ◽  
Frequency Offset ◽  
Sampling Frequency ◽  
Estimation Accuracy ◽  
Computationally Efficient ◽  
Pilot Symbols ◽  
Sampling Frequency Offset ◽  
Efficient Sampling ◽  
Estimation Scheme

The HomePlug Green PHY (HomePlug GP) specification provides an attractive solution to enable smart grid power line communication (PLC) applications by using robust orthogonal frequency division multiplexing (ROBO) mode. This paper proposes a computationally efficient sampling frequency offset (SFO) estimation technique in the HomePlug GP system without relying on pilot symbols. For this purpose, the proposed estimation scheme utilizes the redundant information contained within the repeat coding in the HomePlug GP ROBO mode, thus eliminating the need of dedicated pilots. Computer simulations are conducted to assess the performance of the proposed SFO estimation scheme and to compare it with the conventional decision-directed (DD) estimation schemes. Simulations indicate that the repeat coded ROBO signals are effectively used for the proposed estimation scheme, which provides an affordable estimation accuracy while reducing the complexity compared to the conventional DD estimation schemes.

scholarly journals Inner-symbol Interference (INSI) reduction in OFDM system using distinctive characteristics of the pilot symbols

2020 ◽  
Vol 27 (1) ◽  
pp. 122-129
Author(s):  
Mohammad Bakkar
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Estimation Method ◽  
Multipath Fading ◽  
Estimation Accuracy ◽  
Ofdm Symbol ◽  
Pilot Signal ◽  
Ofdm Signal ◽  
The Times ◽  
Symbol Duration ◽  
Inter Symbol Interference

This research presents a wireless communication system using Quadrature Amplitude Modulation (16QAM) depending on using of the Orthogonal Frequency Division Multiplexing (OFDM).  OFDM transmission system can effectively reduce inter symbol interference (ISI) caused by multipath fading, especially in the case of broadband data transmission. There are two kind of interference; inter symbol interference (ITSI) and inner symbol interference (INSI). ITSI is the interference caused by the delayed waves with larger than OFDM symbol duration, in order to avoid ITSI effectively, we insert guard interval every each OFDM symbol. On other hands, INSI is the interference caused by the delayed waves with less than OFDM symbol duration. To avoid INSI, this work proposes a new scheme in order to estimate the times of delayed waves by using distinctive characteristics of OFDM signal, which is inserted pilot signal periodically in frequency axis before IFFT at the transmitter. In this paper, we evaluate the estimation accuracy of the proposed estimation method and the BER performance of the proposed system under multipath fading environment by computer simulation with MATLAB.

Research on Doppler and Channel Estimation for Multicarrier Spread Spectrum Underwater Acoustic Communication System

2014 ◽  
Vol 1079-1080 ◽  
pp. 752-756
Author(s):  
Yuan Wang ◽  
Zhou Mo Zeng ◽  
Yi Bo Li ◽  
Wen Zhang ◽  
Hao Feng
Keyword(s):  
Channel Estimation ◽  
Compressed Sensing ◽  
Acoustic Communication ◽  
Spread Spectrum ◽  
Orthogonal Frequency Division Multiplexing ◽  
Estimation Method ◽  
Signal Propagation ◽  
Underwater Acoustic Communication ◽  
Mobile Nodes ◽  
Underwater Acoustic

Spreadspectrum orthogonal frequency-division multiplexing (SS-OFDM), which appliesspread spectrum technique into OFDM, performs robustly in severely multipathfading underwater channels. However, this technology is sensitive to thefrequency shift. Furthermore, communication in underwater acoustic (UWA)channels is more vulnerable to Doppler effect than other wireless channels dueto the low speed of acoustic signal propagation. It presents challenges forcommunication between underwater mobile nodes. Therefore, accurate Dopplerfrequency shift estimation and compensation is important. Aself-designed receiver structure for SS-OFDM system including a novel Dopplerscale estimation method and channel estimation via compressed sensing method isproposed. The simulation and experimental results offer strong proofs for ourscheme to be a viable option for acoustic communication between underwatermobile nodes and compressed sensing method outperforms the conventionalleast-squares (LS) method in channel estimation.

Yet another TOA estimation technique for IR-UWB

2013 ◽  
Vol 33 (1/2) ◽  
pp. 286-297 ◽  
Author(s):  
Mustapha Djeddou ◽  
Hichem Zeher ◽  
Younes Nekachtali
Keyword(s):  
Channel Model ◽  
Distance Measure ◽  
Estimation Algorithm ◽  
False Alarm Probability ◽  
Ultra Wideband ◽  
Estimation Accuracy ◽  
Time Of Arrival ◽  
Content Type ◽  
Toa Estimation ◽  
Proportionality Test

Purpose – The paper aims to propose a new method for estimating the time of arrival (TOA) of ultra-wideband (UWB) signals under IEEE 802.15.4a multipath channel model. Design/methodology/approach – The proposed approach is based on a proportionality test and consists in finding out whether two autoregressive (AR) processes, modeling two frames, are proportional or not. The latter operation uses a distance to measure the proportionality between the two AR processes. Findings – The developed technique may be used in two ways, sample-by-sample or block-by-block, according to the required ranging accuracy. It is important to note that the method offers flexibility between the computational load and the needed estimation accuracy. Moreover, the proposed method uses a threshold that is derived analytically according to a preset false alarm probability. Practical implications – Simulation experiments are conducted to assess the performance of the new TOA estimation algorithm. Thereby, the comparison is done against the well-known CLEAN algorithm for a sample-by-sample based TOA estimation and against three energy detector based receiver algorithms. The obtained results highlight the effectiveness of the developed approach. Originality/value – The developed TOA estimation algorithm is completely different from other techniques in the literature, and it is based on a proportionality test between two sliding frames. These latter are modeled by two AR processes. Then a distance measure is used to check whether or not the power spectral densities are proportional.

scholarly journals Source Geolocation in Urban Environments Using Multipath Fingerprinting

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Ram M. Narayanan ◽  
Brian R. Phelan ◽  
Erik H. Lenzing
Keyword(s):  
Mobile Communications ◽  
A Priori ◽  
Estimation Method ◽  
Location Estimation ◽  
Estimation Accuracy ◽  
Time Of Arrival ◽  
Angle Of Arrival ◽  
Feature Vectors ◽  
Area Of Interest ◽  
Estimation System

A method for determining the location of Global Systems for Mobile Communications (GSM) mobile transmitters is proposed. Our approach estimates the location of a source without the use of multilateration or Line-of-Sight (LOS) techniques. A Multipath Characteristic Database (MCD) containing the multipath feature vectors, for each possible transmitter location within an area of interest, is populated via ray-tracing software simulations. The multipath characteristics of interest are angle-of-arrival (AOA) (azimuth) and time-of-arrival (TOA). By minimizing the “distance” between estimated and simulated multipath feature vectors, an estimate for the actual source location can be obtained. The development of the estimation method is presented, followed by a detailed analysis of its estimation accuracy. Since the proposed method utilizes a simulated multipath signature database based upon the knowledge of the environment and the terrain, the need fora priorisoundings from the area of interest is eliminated, thus making this location estimation system suitable for application in denied territories. Location accuracies compare favorably with the requirements for the location of wireless 9-1-1 callers as recommended by the Federal Communications Commission (FCC).

scholarly journals Underwater 3D Doppler-Angle Target Tracking with Signal Time Delay

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3869
Author(s):  
Jun Su ◽  
Yaan Li ◽  
Wasiq Ali ◽  
Xiaohua Li ◽  
Jing Yu
Keyword(s):  
Time Delay ◽  
Target Tracking ◽  
Unscented Kalman Filter ◽  
Signal Propagation ◽  
The State ◽  
Estimation Accuracy ◽  
Target Range ◽  
Implicit Equations ◽  
Passive Acoustic ◽  
Signal Time

The traditional target tracking is a process of estimating the state of a moving target using measurement information obtained by sensors. However, underwater passive acoustic target tracking will confront further challenges, among which the system incomplete observability and time delay caused by the signal propagation create a great impact on tracking performance. Passive acoustic sensors cannot accurately obtain the target range information. The introduction of Doppler frequency measurement can improve the system observability performance; signal time delay cannot be ignored in underwater environments. It varies with time, which has a continuous negative impact on the tracking accuracy. In this paper, the Gauss–Helmert model is introduced to solve this problem by expanding the unknown signal emission time as an unknown variable to the state. This model allows the existence of the previous state and current state at the same time, while handling the implicit equations. To improve the algorithm accuracy, this paper further takes advantage of the estimated state and covariance for the second stage iteration and propose the Gauss–Helmert iterated Unscented Kalman filter under a three-dimensional environment. The simulation shows that the proposed method in this paper shows superior estimation accuracy and more stable performance compared with other filtering algorithms in underwater environments.

scholarly journals Efficient Joint Estimation of Carrier Frequency and Sampling Frequency Offsets for MIMO-OFDM ATSC Systems

Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 554 ◽  
Author(s):  
Yong-An Jung ◽  
Young-Hwan You
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Mean Squared Error ◽  
Estimation Method ◽  
Multipath Fading ◽  
Sampling Frequency ◽  
Joint Estimation ◽  
Estimation Accuracy ◽  
Multipath Fading Channel ◽  
Mimo Ofdm ◽  
Frequency Offsets

Multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) is appealing for the provision of high spectral efficiency in digital terrestrial broadcast systems. To fully obtain its advantageous features, it is very important to remove the frequency mismatch between the transmitter and the receiver. In this paper, we present the performance analysis of joint estimation of carrier and sampling frequency offsets in the MIMO-OFDM-based advanced television systems committee (ATSC) 3.0 system. In the MIMO-OFDM ATSC system, the continual pilot (CP) is primarily utilized to perform frequency synchronization. To efficiently suppress an unwanted bias introduced by the presence of random-likely located CPs, an optimal pilot subset is selected to form the basis of least squares frequency-offset estimation. A closed-form mean squared error is derived in the context of MIMO-OFDM, considering the multipath fading channel. We show via computer simulations and numerical analysis that the proposed estimation method achieves higher estimation accuracy than the existing estimation method.

scholarly journals Low-complexity beam-domain channel estimation and power allocation in hybrid architecture massive MIMO systems

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Xiao Chen ◽  
Zaichen Zhang ◽  
Liang Wu ◽  
Jian Dang
Keyword(s):  
Channel Estimation ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Communication Systems ◽  
Mimo Systems ◽  
Beam Steering ◽  
Estimation Method ◽  
Low Complexity ◽  
Estimation Accuracy ◽  
Hybrid Architecture

Abstract In this journal, we investigate the beam-domain channel estimation and power allocation in hybrid architecture massive multiple-input and multiple-output (MIMO) communication systems. First, we propose a low-complexity channel estimation method, which utilizes the beam steering vectors achieved from the direction-of-arrival (DOA) estimation and beam gains estimated by low-overhead pilots. Based on the estimated beam information, a purely analog precoding strategy is also designed. Then, the optimal power allocation among multiple beams is derived to maximize spectral efficiency. Finally, simulation results show that the proposed schemes can achieve high channel estimation accuracy and spectral efficiency.

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