Research And Implement In Timing And Frequency Synchronization In SC-FDE System

Single carrier frequency domain equalization (SC-FDE) technology is an importantcomponent of broadband wireless access system technology, which can be effectiveagainst frequency selective fading of wireless channels and achieve a large-capacityhigh-rate wireless transmission. Its algorithm complexity is greatly decreased, comparedwith the single carrier domain equalization (SC-TDE) technology. And its PAPR is alsoon a significant decline with respect to the OFDM technology. The channelcharacteristics with time readily changing will bring greater multipath delay spread andDoppler frequency shift in the received signal, which has a great impact on the systemreliability. Therefore, the frequency synchronization problems of the receiving end areneeded to be solved.For the SC-FDE transmission system, there are three problems, the poor timingsynchronization accuracy, and the lack of symbol synchronization effects and frequencyshift estimation precision. This paper studies the timing and frequency synchronizationmethod based on a special training sequence. The main work is completed as follows:on the frame structure, using two consecutive Zadoff-Chu sequences, the same length ofdata symbols, construct the training sequence; on the timing and frequencysynchronization algorithm, using the good autocorrelation of the training sequence,through the various delays associated to received signal, obtain the time coarsesynchronization position, the best symbol extraction location and the small frequencyshift. The simulation results show the time domain synchronization method in this papercompared with traditional methods has the advantages of the timing accuracy, samplingthe best and the high estimation accuracy of frequency shift. Finally the timimg andfrequency synchronization method is implemented on FPGA, and proves the reliabilityand accuracy of this method from the practice.