An Improved OFDM Time-Frequency Synchronization Algorithm Based on CAZAC Sequence

Abstract

An improved OFDM time-frequency synchronization algorithm based on CAZAC (Constant Amplitude Zero Auto Correlation) sequence is proposed to solve the problem that the traditional algorithm is difficult to balance between timing synchronization accuracy and calculation complexity. The CAZAC sequence was introduced to improve the structure of the training sequence of conventional algorithms. The conjugate symmetry of the training sequence of the receiving end in the time domain was used for the timing estimation. Fractional frequency offset assessment Then the effect of the integral frequency offset on the CAZAC sequence was analyzed, and the integer frequency offset was completed by calculating the CAZAC sequence. The algorithm achieves higher timing synchronization accuracy with lower computational complexity, and the accuracy of frequency offset estimation is also higher than that of traditional algorithms. Theory and simulation prove that the proposed algorithm has good timing estimation and frequency offset estimation performance under the Multipath fading channel.