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Orthogonal Frequency Division Multiplexing (OFDM) systems are very sensitive to symbol timing and frequency offsets. Therefore, it is very important to achieve a high precision time and frequency synchronization. With the absence of pilot symbols, blind synchronization algorithms using different metric functions or statistics of the received signal can be used. In this paper, a new blind symbol timing...
In free-viewpoint TV system considering hybrid transmission through heterogeneous networks, our proposed scheme using Zadoff-Chu sequence can improve synchronization performance of this system.
The emerging market of the Internet of Things is constrained by the energy-efficiency of each layers having a role in Wireless Personal Area Networks (WPANs). In this context, adaptivity is a key technique to address the need of low-power consumption in unpredictable environments, by providing at any time a low-margin operating mode. For this purpose, the paper presents an IEEE 802.15.4 digital baseband...
In the article the effect of sampling on ranging code pseudorange measurement error is considered. The formula for estimation of error caused by pseudorandom sequences sampling is proposed. The sampling error behavior is investigated.
Low-power, low received signal-to-noise-ratio (SNR) signals have potential for reducing the impact on marine life from acoustic communications. Here we explore the use of bandlimited pseudo-noise m-ary orthogonal code keying (MOCK) scheme using m-sequences. Analysis and simulation of receiver structure for synchronisation and data demodulation performance is carried out. Performance of M-OCK is compared...
Side Channel Attacks (SCA) using power measurements are a known method of breaking cryptographic algorithms such as AES. Published research into attacks on AES frequently target only AES-128, and often target only the core Electronic Code-Book (ECB) algorithm, without discussing surrounding issues such as triggering, along with breaking the initialization vector. This paper demonstrates a complete...
In radio astronomy, the radio spectrum is used to detect weak emission from celestial sources. However, more and more observations are polluted by man-made radio frequency interferences (RFI). To some extent, the final power spectral estimation can be preserved by processing the polluted channels in real time. In the case of digital modulated RFI, we propose to use their cyclostationary properties...
In this paper 1 we discuss the design issues of an Ultra Wide Band (UWB) receiver, targeting a single-chip CMOS implementation for low data-rate applications like ad hoc wireless sensor networks. A non-coherent transmitted-reference (TR) receiver is chosen because of its small complexity compared to other architectures. Issues, challenges and possible design solutions are discussed. In particular,...
The implementation of an interferometric positioning experiment for measuring the baseline vector between two locations is presented. Two identical software receivers, each consisting of an antenna, a low-cost USB front-end collecting GNSS signals in the L1 band and a laptop, are placed at both ends of the baseline. Cross-correlating the raw signals in post-processing yields differential code delay...
In underwater acoustic communications, Doppler effect should be described by Doppler scale which adversely affects the performance of the communication system. This paper presents a method by employing the hyperbolic frequency modulation (HFM) signal as a channel probe to make Doppler estimation and timing synchronization simultaneously. The Doppler compensation is realized by linear interpolation...
This paper presents the design and evaluation of a flexible UHF RFID testbed, which is intended to be used for developing real time localization systems. It is based on an off the shelf software defined radio platform, i.e. the National Instruments USRP-2922. Special requirements for a localization algorithm based on a superimposed Direct Sequence-Spread Spectrum signal which is currently under active...
In this paper, we propose a robust timing and frequency synchronization algorithm for the orthogonal frequency division multiplexing (OFDM) systems. The algorithm we proposed can achieve accurate timing and frequency synchronization in time-domain by using the preamble consisting of only one training symbol based on constant amplitude zero autocorrelation (CAZAC) sequence and a new weighting factor...
This paper demonstrates the Data aided (DA) synchronization for single user in IEEE 802.15.4a channel for coherent and Non-coherent UWB-IR receivers. Random Timing Offset before every transmitted sequence is estimated using Walsh codes which act as pilot sequence to achieve timing synchronization. Sliding correlation window of appropriate length is used to perform correlation of received bit stream...
Narrowband power line communications (NB-PLC) operating in the 3–500 kHz frequency band is proposed as a solution to support the emerging Smart Grid applications that aim to optimize the efficiency and reliability of the power grids. PLC is attractive for Smart Grid communications as it can be deployed over the existing power grids without any additional infrastructure. However, PLC suffers from impulsive...
The Vectron is a new pulse-coherent Doppler sonar system that has been developed to allow remote measurement of turbulent velocities at mid-water depth (O 10 m distant from the instrument transducers) to meet the measurement and monitoring needs of the in-stream tidal generating industry. Multiple sonar units (based on the Nortek AD2CP hardware platform) are networked together and the instrument is...
In this paper, we present a fast algorithm of time synchronization between User Equipment (UE) and Base Station (BS) which is suitable for Long Term Evolution (LTE) Random Access Channel (RACH). The algorithm reduces the complexity more than 1.5 times. Further, if the SNR is above a threshold, the algorithm allows to extremely reduce the complexity of synchronization more than 3 times. The presented...
In this paper a novel method for synchronization and cell search in 3GPP LTE downlink (DL) system has been proposed. This method performs the symbol timing and physical-layer cell identity estimation in frequency domain with less complexity, utilizing the frequency domain properties of the primary and secondary synchronization signals. The primary synchronization signals have good orthogonal and frequency...
In Long Term Evolution (LTE) systems, cell search is performed by each User Equipment (UE), to detect the cell identity. The received subframe index and radio frame timings in the downlink are also acquired. Cell search is performed using the Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) in a hierarchical manner. In this paper we have simulated the schemes for PSS...
For orthogonal frequency division multiplexing (OFDM) receivers, the mutual orthogonality of the subcarriers is preserved only if the estimated symbol timing error lies in the lock-in region. Conventionally, a bias is added to the coarse symbol time offset (STO) estimate to move the symbol timing error into the lock-in region, thus increasing the lock-in probability. Upon review of the literature,...
A novel preamble structure is proposed for a timing estimation for orthogonal frequency division multiplexing (OFDM) systems such as the IEEE 802.11 and the IEEE 802.15.4g/4m. The boundary estimation becomes easy because of the outstanding correlation property between the short training sequence (STS) and the proposed long training sequence (LTS). The proposed method can be applied to OFDM systems...
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