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As the WIFI access points are widely deployed, the received WIFI signal strength is commonly adopted as a positioning characteristic for mobile phone based indoor localization systems. Although WIFI based localization has achieved great development, there are still several key challenges in tracking applications, such as how to modify irregular trajectory obtained from the sequential positioning results...
An indoor positioning system based on Receive Signal Strength Indication(RSSI) from wireless access equipment has become very popular in recent years. This system is very useful in many applications such as tracking service for older people or customer inside living communities, mobile robot localization, logistics systems etc. While outdoor environment using Global Navigation Satellite System(GNSS)...
With the rapid development and ubiquitous usage of Wireless Local Area Networks (WLAN), Location Based Systems (LBS) employing Signal Strength techniques have become an attractive area of research for location estimation in indoor environments. In this paper we propose a robust fingerprint method for localization based on the traditional K-Nearest Neighbor (KNN) method. Instead of considering a fixed...
As a new tool, GNSS-R with L-band navigation satellite signal has been applied to measure soil moisture based on its higher performance and lower cost. This paper analyzes the reflected signals from navigation satellite and the soil moisture calculation model from the electromagnetic wave polarization and dielectric constant. One ground based experiment was conducted in Beijing Vegetable Research...
The paper contrast varied GNSS (Global Navigation Satellite System) reflections software receivers with hardware receivers. Both the architecture and the components for GPS reflections software receiver were presented including direct signals and reflections antennas, two channel RF (radio frequency) front ends, high speed A/D converter and the workstation for data processing. Principle original signal...
In LTE-Advanced (LTE-A), heterogeneous networks (HetNet) comprising of pico and femto cells are laid onto the traditional well planned macro cells, are extensively investigated for improving the overall system throughput. Cell range expansions (CRE) are effectively used in HetNets to enhance the system coverage as well as the cell-edge throughput. In a HetNet there is a severe interference specifically...
The phase synchronization is one of the key technologies for bistatic radar. Traditionally, it is used to be synchronized by sampling, analyzing and modifying the phase signal in the windowed FFT spectrum. But, the sync-error can be introduced by sampling the asynchronous signals. In this paper, we use a new method called All-Phase FFT. By the way of All-Phase FFT Analysis, the initial phase can be...
The paper analyzes the peak to average power ratio (PAPR) of Multi-carrier code-division multiple access (MC-CDMA) system and gives a mathematic expression on complementary cumulative distribution function (CCDF) of PAPR based on the correlation functions of the spreading sequences. It is shown that the PAPR varies as the changing of correlation functions of the sequences. PAPR property is studied...
We propose a new recursive least square (RLS) based method for precisely tracking carrier and code navigation signals of BOC (m, n), Alt- BOC(m, n) any other systems in multipath environment. The method can estimate multipath profile at high resolution by self-adaptively filtering local correlation function according to correlation value after demodulation and spectrum dispreading, and the filter...
From concatenation view, this letter analyzed the construction of frequency hopping (FH) sequences by Junjie Chen, Guuchang Yang and Chiaming Yang based on prime codes. It is concluded that the object FH sequences can be constructed by concatenating the frequency-shifted or time-shifted versions of prime codes sequences. Upon this conclusion, two new further thoughts are deduced and more families...
From both construct formula view and finite field model view, the relationship between concatenated prime codes and quadratic prime codes has been studied in this paper. As a result, two new methods of constructing frequency hopping (FH) sequences are derived, designated as exchange and time shift, which are still generalized and combined. Finally, one application of the novel methods to the general...
From concatenation view, this paper analyzed the relationship between quadratic prime codes and prime codes. It is concluded that quadratic prime codes can be constructed by concatenating the time-shift or frequency-shift versions of prime codes sequences. Based on this analysis, two new further thoughts are deduced to construct more families of frequency hopping sequences with same properties as...
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