Precise Ranging Technology Application Research Based on IEEE802.15.4a

2014 ◽  
Vol 631-632 ◽  
pp. 558-562
Author(s):  
Zi Hui Wei ◽  
Zheng He Feng ◽  
Zhi Feng Wang ◽  
Duan Bo Cai

To solve the poor location accuracy of wireless sensor networks using Received Signal Strength Indication (RSSI) ranging. Time Of Flight (TOF) ranging is used to ensure the accuracy based on two optional physical layer of Impulse Radio-Ultra Wide-Band (IR-UWB) and Chirp Spread Spectrum (CSS) in IEEE802.15.4a. In this paper, we designed ranging module utilizing CSS and UWB. In the Line Of Sight (LOS) and None Line Of Sight (NLOS) environments ranging accuracy test is implemented, the test results show that the IR-UWB ranging technology can achieve higher ranging accuracy and better multipath resistance compared to CSS.

Author(s):  
Songzuo Liu ◽  
Habib Hussain Zuberi ◽  
Yi Lou ◽  
Muhmmad Bilal Farooq ◽  
Shahabuddin Shaikh ◽  
...  

AbstractLinear chirp spread spectrum technique is widely used in underwater acoustic communication because of their resilience to high multipath and Doppler shift. Linear frequency modulated signal requires a high spreading factor to nearly reach orthogonality between two pairs of signals. On the other hand, nonlinear chirp spread spectrum signals can provide orthogonality at a low spreading factor. As a result, it improves spectral efficiency and is more insensitive to Doppler spread than the linear counterpart. To achieve a higher data rate, we propose two variants (half cycle sine and full cycle sine) of the M-ary nonlinear sine chirp spread spectrum technique based on virtual time-reversal mirror (VTRM). The proposed scheme uses different frequency bands to transmit chirp, and VTRM is used to improve the bit error rate due to high multipath. Its superior Doppler sensitivity makes it suitable for underwater acoustic communication. Furthermore, the proposed method uses a simple, low-power bank of matched filters; thus, it reduces the overall system complexity. Simulations are performed in different underwater acoustic channels to verify the robustness of the proposed scheme.


2014 ◽  
Vol 484-485 ◽  
pp. 933-937
Author(s):  
Fu Na Li ◽  
Lin Wei Yang ◽  
Ying Zeng

This paper introduces analysis the development process of CAD technology, application of the AutoCAD software in engineering field and teaching as well as the significance of the development of two times the. This paper analyzes in detail the development of common language, and the use of Visual BASIC development and application of software based on AutoCAD. The author elaborates the software interface design and method calls AutoCAD in VB. Finally, the design and implementation of a programming language re-development system based on AutoCAD is concerned. The test results show that the developed AutoCAD two development system has good practical value.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Sumedh Yadav ◽  
Mathis Bode

Abstract A scalable graphical method is presented for selecting and partitioning datasets for the training phase of a classification task. For the heuristic, a clustering algorithm is required to get its computation cost in a reasonable proportion to the task itself. This step is succeeded by construction of an information graph of the underlying classification patterns using approximate nearest neighbor methods. The presented method consists of two approaches, one for reducing a given training set, and another for partitioning the selected/reduced set. The heuristic targets large datasets, since the primary goal is a significant reduction in training computation run-time without compromising prediction accuracy. Test results show that both approaches significantly speed-up the training task when compared against that of state-of-the-art shrinking heuristics available in LIBSVM. Furthermore, the approaches closely follow or even outperform in prediction accuracy. A network design is also presented for a partitioning based distributed training formulation. Added speed-up in training run-time is observed when compared to that of serial implementation of the approaches.


2014 ◽  
Vol 513-517 ◽  
pp. 1494-1498 ◽  
Author(s):  
Zhang Hong ◽  
Jun Jie Wang ◽  
Ai Sheng Ma

In view of the problems in the current domestic and international remote wireless meter reading system, propose the remote wireless meter reading terminal system based on ZigBee technology combined with GPRS technology, carry out the hardware circuit design of each module, establish ZigBee wireless meter reading network based on 802.15.4 layer networking protocol, design a more practical remote wireless meter reading protocol and data transmission format. Test results show that it has realized the formation of ZigBee network, collection and remote transmission of meter data, terminal equipment parameters modification and other functions to achieve the terminal design requirements.


2015 ◽  
Vol 734 ◽  
pp. 31-39
Author(s):  
Wen Yang Cai ◽  
Gao Yong Luo

The increasing demand for high precision indoor positioning in many public services has urged research to implement cost-effective systems for a rising number of applications. However, current systems with either short-range positioning technology based on wireless local area networks (WLAN) and ZigBee achieving meter-level accuracy, or ultra-wide band (UWB) and 60 GHz communication technology achieving high precision but with high cost required, could not meet the need of indoor wireless positioning. This paper presents a new method of high precision indoor positioning by autocorrelation phase measurement of spread spectrum signal utilizing carrier frequency lower than 1 GHz, thereby decreasing power emission and hardware cost. The phase measurement is more sensitive to the distance of microwave transmission than timing, thus achieving higher positioning accuracy. Simulation results demonstrate that the proposed positioning method can achieve high precision of less than 1 centimeter decreasing when various noise and interference added.


2013 ◽  
Author(s):  
M. Crepaldi ◽  
A. Chiolerio ◽  
T. Tommasi ◽  
D. Hidalgo ◽  
G. Canavese ◽  
...  

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