The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Time synchronization is of great significance in underwater acoustic (UWA) networks. Many functions, such as network protocol stack, sleep-scheduling, and localization, are based on time synchronization. Because underwater sound speed is comparatively slow, synchronization protocols encounter a long propagation latency problem, which differs from those in terrestrial sensor networks. As a result,...
In this paper we propose a scheme of a bank of signal replicas for the synchronization step of an underwater acoustic communication system. Each replica is designed to be Doppler-tolerant for a different section of a possible range of relative radial velocities between the transmitter and the receiver. We suggest a statistical approach for determining the width of each velocity section based on the...
The special underwater environment give the localization of Underwater Sensor Networks(UWSNs) great challenge. In this page, the depth information is considered to use for localization. A new TDoA approach named TBLT is proposed, which do not rely on time synchronization. According TBLT, a new localization scheme named NLSBT is designed for UWSNs. Combining the depth information with projection technique...
An effective algorithm is proposed to estimate the spread spectrum sequence in direct spread spectrum sequence (DSSS) signal with the non-stationary noise for the underwater acoustic non-cooperative communication system. Conventional estimators are generally ineffective in detecting signals under low signal-to-noise ratio (SNR). The estimator proposed in this paper only needs the demodulation for...
According to the feature of underwater acoustic channel (UWA), the implementation of time and frequency synchronization is introduced. In the sea area, the experiment result show that the synchronization method of OFDM system has the better performance.
In this paper, a time synchronization method for underwater wireless sensor networks (UWSN), UA-TSP, is presented. The proposed method not only compensates the main time delay in acoustic communication, but also decreases the cumulate errors in the multi-hop scene through a loop convergence method. The implementation of UA-TSP is combined with the nodes discovering process, and less control frame...
Considering the features of Underwater Acoustic channel and the sensitivity versus synchronization for CI/OFDM system, A time and frequency synchronization method based on Constant Amplitude Zero Auto-Correlation(CAZAC) sequence is presented. The time offset estimation and carrier frequency offset estimation can be achieved simultaneously. The fractional part and integral part of carrier offset estimation...
The highly precise time synchronization is very important to underwater acoustic (UWA) networks (UANs) and underwater targets and vehicles. It consists of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over given area. The UANs are envisioned to enable applied widely for oceanographic data collection, pollution monitoring, offshore exploration,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.