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The paper deals with the estimation method of a carrier and time of arrival by chirp-like phase-coded sequence. The developed estimation method of the carrier and time of arrival is suitable for primary synchronization upon signal detection in phase and frequency modulation modems. This method is of less computational complexity relative to the realization of matched filter assembly. To implement...
The need for high data rate is growing since the multimedia applications are gaining popularity which needs high data rate and quality of service. Multiple Input Multiple Output (MIMO) transmission system is one of the most promising approach of the Smart Antenna Technology which uses multiple antennas in the transmitter and the receiver side and is currently followed for high-rate wireless communication[1]...
The problem of carrier frequency and phase synchronization exists in most wireless digital communication systems. These offsets are generally results from the Doppler effect, oscillator instabilities, and unknown transmission delays between receiver and transmitter. In this paper, we propose a joint synchronization algorithm applicable for short-burst PSK modulation systems. In the coarse estimation,...
In this paper, we present the simulation results of FFO(fractional frequency offset) influences on PLC preamble correlation based PLC synchronization in DOCSIS 3.1 Downstream. FFO makes inter-carrier interferences and breaks orthogonality in OFDM based transmission system. It degrades the performance of OFDM by reducing SNR(signal to noise ratio). The performance of PLC synchronization is influenced...
In this paper we study the problem of estimating the unknown delay(s) in a system where we receive a linear combination of several delayed copies of a known transmitted waveform. This problem arises in many applications such as timing-based localization or wireless synchronization. Since accurate delay estimation requires wideband signals, traditional systems need high-speed AD converters which poses...
We consider low latency uplink communication where users transmit their signal using generalized frequency division multiplexing (GFDM) with K subcarriers and M sub-symbols. The proposed approach for synchronization exploits both training subcarriers and training subsymbols embedded in a GFDM symbol. A frequency domain training sequence (FD-TS) of length M is loaded on each training subcarrier, and...
Two estimation algorithms for the spreading sequence in DSSS signals are proposed. Some of previously proposed algorithms have some drawbacks such as large computational complexity, low estimation accuracy and poor accuracy by increasing the length of spreading sequence period. In this paper by using an initial estimate of chips, we can improve recursively the final decision with low computational...
In this paper, we propose a timing synchronization method for orthogonal frequency division multiplexing (OFDM) systems by exploiting the averaged differential correlations of preamble symbol. For the designed simple preamble whose second half-symbol is the complex conjugate of the first one in the time-domain, the proposed timing synchronization method has an impulse-shaped timing metric. Simulation...
In this paper, we propose an efficient preamble structure for improving the timing synchronization in Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems. The proposed short preamble symbol consists of four equal duration sub symbols, the first and third of which are CAZAC sequences. The second sub symbol is comprised of PN sequences. The fourth sub symbol...
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 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...
As an overlay cognitive radio, transform domain communication system (TDCS) has been proposed to support reliable communications with low probability of interception. However, most of research on TDCS assume perfect synchronization to simplify algorithm design. In this paper, we present a low complexity symbol timing offset (STO) and carrier frequency offset (CFO) estimation method for practical TDCS...
A base station (BS) in an LTE cellular network, transmits primary synchronization signal (PSS) in every frame to facilitate synchronization. PSS are derived from Zadoff-Chu (ZC) sequences. User equipment (UE) determines physical layer identity and frame timing of BS transmissions, by PSS acquisition. The techniques to detect PSS are typically based on cross-correlating the received signal with local...
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 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...
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...
This work presents a synchronization approach using an embedded training sequence in the payload of a Generalized Frequency Division Multiplexing (GFDM) symbol. The proposal explores the pulse- shaped subsymbol structure of GFDM to design a midamble. Autocorrelation, correlation and false alarm threshold criterion are the tools used for estimation of frequency offset and the time arrival of the first...
Considering both large cost and high complexity of current carrier synchronization systems at low Signal-to-Noise Ratio (SNR), an adaptive carrier synchronization system design in accordance with Green communication is proposed. First, the proposed design takes advantage of parameter control method to change an optimal scheme to some suboptimal schemes. Within the requirement of satisfying less SNR...
The sampling rate offset (SRO) phenomenon in wireless acoustic sensor network (WASN) is considered in this work. The use of different clock sources in each node results in a drift between the nodes' signals. The aim of this work is to estimate these SROs and to re-synchronize the network, enabling coherent multi-microphone processing. First, the link between SRO and the Doppler effect is driven. Then,...
A new preamble structure is proposed for Narrowband Power Line Communication (NB-PLC) system, and therefore a corresponding timing estimator with interval detection and pattern matching is put forward. In the new estimator, firstly the received signals are conducted cross-correlation with the preamble in the transmitter, then the cross-correlation values are obtained and divided into several groups...
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