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In this paper, a new method of timing synchronization was proposed for 802.16e OFDMA downlink which consists of coarse frame detection and fine timing synchronization. In coarse frame detection a method had been proposed, which reduced the uncertainty existing in conventional method. For fine timing synchronization, another method was represented to improve timing precision based on special preamble...
In this paper, we propose an efficient scheme using a new single-symbol preamble structure for OFDM data-aided synchronization. The preamble symbol is constituted of two successive equal-duration sub-symbols, the second one of which is a differentially encoded version of the first one, using an adequately designed precoding sequence. This structure leads to almost perfect channel autocorrelation profile...
Collaborative communication produces high power gain and significantly reduction in bit error rate (BER) if both frequency and phase synchronization are achieved. In this paper a novel collaborative communication system with imperfect phase and frequency synchronization that includes the influence of noise is proposed, modeled, simulated and analyzed. Mathematical expressions are derived for the received...
Timing and frequency synchronization are the important task in receiver. In this paper, an efficient timing and carrier frequency offset (CFO) estimation method for orthogonal frequency division multiple access/ time division duplexing (OFDMA/TDD) mode in IEEE 802.16-2004 standard (WiMAX) is represented. This method has high performance and jointly estimates timing error and CFO. The performance is...
This paper analyses the probability of synchronization-acquisition of HF DFH narrowband short burst communication. It discusses how to choose system parameters for getting better synchronization acquisition probability in different conditions and gives the choice principle of the synchronization-head length, signal detection threshold and synchronization-acquisition threshold of HF DFH narrowband...
Owing to SC-FDE (single carrier with frequency domain equalization) systems perform equalization in frequency domain, carrier frequency synchronization and timing synchronization are the most important preconditions. A novel synchronization method is proposed in this paper, which adopts new structure of training symbols and new calculation method. Simulation results demonstrate that the proposed method...
For WLAN applications frequency synchronization is one of the most important issues. The preamble allows the receiver to use efficient maximum likelihood algorithms to estimate and correct for the frequency offset, before the actual information portion of the packet starts. In order to increase the performance and provide frequency synchronization in orthogonal frequency-division multiplexing systems,...
In this paper, we propose a new frequency synchronization algorithm for orthogonal frequency division multiplexing (OFDM) system by combining PN sequences with cyclic prefix. It is the improvement of Tufvesson's algorithm. In the new algorithm, the frequency offset is estimation with two steps. First a small step (span of the correlation) is used to estimate frequency offset which will result in a...
While two-dimensional (2-D) orthogonal variable spreading factor (OVSF) codes were proposed for multicarrier direct-sequence code-division multiple-access (MC/DS-CDMA) systems in order to eliminate multiple-access interference, the number of orthogonal sequences (or code cardinality) was restricted by the number of carrier frequencies. Non-orthogonal 2-D frequency-time-spreading (FTS) codes were then...
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