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This paper discusses the implementation of proportional resonant (PR) current controllers for a Voltage Source Converter (VSC) with LCL filter which is synchronized to the grid by virtual flux (VF) estimation with inherent sequence separation. Even though there is an extensive amount of literature and studies on the PR current controller for tracking the current reference of a VSC in the stationary...
The rotor unbalance will excite fundamental frequency vibration in the flywheel energy storage system. To reduce the cost and improve the reliability of the system, the vibration signals can be used for speed estimation and phase synchronization. For this purpose, this paper proposes a novel synchronization method based on single-phase synchronous reference frame PLL and offers the specific structure...
Position estimation of UAVs is usually done using onboard sensors such as GPS and camera. However, in certain practical situations, the measurements of both the GPS and the onboard camera of the UAV might not always be available or reliable. This paper investigates the possibility to overcome situations in which a UAV is blind, i.e. situations in which its onboard position sensors and estimates fail,...
An energy efficient synchronization method is presented for an OFDM-based Time Division Cooperative Transmission (TDCT) system for the purpose of range extension. The proposed algorithm operates on a novel preamble consisting of two OFDM symbols. In TDCT, copies of the packet are transmitted through different time slots. Exploiting dependence between the synchronization parameters of the different...
Synchronization of a Wireless Sensor Network is a crucial task and is based on a precise syntonization of all clocks within the network. The synchronization precision is usually closely connected to the positioning accuracy in networks for the purpose of localization. This paper introduces a concept, how the clocks of low-complexity stationary receivers can be adjusted to the same frequency with the...
Considering both inefficiency of the pilot usage and high complexity of current carrier synchronization algorithms for burst-mode systems, a novel distributed joint time-frequency domain (DJTFD) carrier synchronization algorithm is proposed. The frequency-domain estimation has a large residual offset with limited pilot overhead. So we need the distributed time-domain estimation to guarantee both large...
Time synchronization is one of the most fundamental and widely employed services in networks. Because of long propagation delay in underwater acoustic sensor networks (UASNs), the time synchronization becomes more challenging. To solve these challenges, this paper presents a new synchronization and localization protocol (TSLA), which uses anchor nodes to broadcast one-way packets to synchronize and...
In the long term evolution (LTE) uplink systems, reference signals based on Zadoff-Chu sequences are employed for time synchronization and block type channel estimation because the pilots are inserted into all the subcarriers of one single carrier-frequency division multiple access (SC-FDMA) symbol with a certain period. The block-type channel estimation can be adopted for slowly fading channel while...
The aircraft separation system is mainly made up of explosive device. In order to improve the reliability assessment for the aircraft separation system, the reliability model was established, and a new method of synthetic reliability assessment for the aircraft separation system was proposed. According to the function characteristics of explosive device, the separation system was divided into three...
This paper reports the basic analysis for constructing a method of estimating the one-way delays under delay asymmetry and unknown relative clock offset. This estimation method requires to perform a handshake by transmitting one packet along each of the two uni-directional paths. The sending and receiving times of a packet are measured at the sender and the receiver, respectively, according to the...
In this paper, a pilot-aided frequency synchronization scheme for orthogonal frequency division multiplexing (OFDM) systems is proposed. A maximum likelihood (ML) estimator based on Double Dwell Synchronization (DDS) is employed for offset estimation and correction. The proposed DDS scheme provides an accurate estimate over a wide estimation range with reduced computational complexity for both AWGN...
In this paper, an efficient preamble designed for the burst mode continuous phase modulation (CPM) signals is proposed. The innovative preamble is based on the combination of a single tone signal and a unique CPM signal. Like the preamble adopted in MIL-188-181B standard, the proposed preamble can estimate the carrier frequency and phase offset, and acquire the symbol timing and frame synchronization...
IEEE 802.11p is a new standard to support intelligent transport system (ITS) applications which is an approved amendment to the IEEE 802.11a standard to add wireless access in vehicular environments. Timing synchronization is studied a lot for IEEE 802.11a, but for IEEE 802.11p, there is few literature. Therefore, a new method is put forward and the characteristics of the timing synchronization samples...
Integration and exploitation of information collection across a distributed network of assets usually requires the establishment and maintenance of registration of coordinates across the nodes of the network. Here “registration” covers a range of possibilities, including clock synchronization and registration of frames of reference. The registration problem is posed in terms of network represented...
In recent years, communications systems through mains, known as PLC (Powerline Communication), have received a lot of interest as part of intelligent networks or smart grids, as well as for multimedia applications at homes. In broadband PLC, systems using multicarrier modulations allow the mitigation of selective frequency fading in the channel. Nevertheless, these modulations require accurate time...
This paper proposes a low complexity fine frame synchronization method based on channel impulse response (CIR) estimation for DVB-T2 system. The proposed algorithm resolves the CIR rotation ambiguity, which is caused by the error in the coarse frame synchronization due to stronger secondary paths, using a novel scheme for channel and SNR estimation. Unlike previous methods that utilize the data symbols,...
In this paper, we propose a new position sensorless drive system for an interior permanent magnet synchronous motor (IPMSM) with maximum torque control. The proposed method is based on extended electromotive force (EEMF) and voltage injection synchronized with a pulse-width modulated (PWM) carrier. In the proposed method, in order to estimate the magnetic pole position using the EEMF, there is no...
A well-known issue with existing power systems is rapid and accurate synchronisation to grid voltages when the system is unbalanced under grid fault conditions and corrupted with harmonics. This paper presents a novel phase locked loop technique for grid synchronisation technique using the energy operator. A comparative study is undertaken to investigate the accuracy and robustness of this technique...
This paper explores using the first subsymbol in the structure of a GFDM symbol as a pseudo circular preamble. As data and training sequence overlap in the GFDM structure, an initial estimation approach for isolating the preamble information from the data is presented. The concept allows for adaptation of state-of-the-art techniques developed for OFDM in order to estimate time offset at every GFDM...
This paper introduces the coarse time-of-arrival (ToA) estimation in wireless sensor networks (WSN) via orthogonal frequency division multiple access (OFDMA). In the proposed technique, each sensor node exploits a set of orthogonal subcarrier as its allocated signature to respond of the ToA estimation requests transmitted by target nodes. The target node utilizes the orthogonality across sub-carriers...
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