Blind Time and Frequency Synchronization Based on the Cyclic Prefix for OFDM Systems

The orthogonal frequency division multiplexing (OFDM) systems are an efficient method for data transfer with high rate in most of the communication systems of today due to resistance against the errors arising from multipath of dispersion environment and decreasing the inter-symbol errors. In these systems, it is necessary to use the blind methods to estimate the time and frequency offset for achieving the highest spectral productivity and the optimal use of bandwidth. Therefore, in this paper, we suggest a synchronizing algorithm of blind symbol for OFDM systems that uses a new time function based on the repetition of cyclic prefix. The maximum of this function, aside from the channel conditions, corrects the time offset, such that this function follows an unbiased estimation of time offset in the AWGN channels. We have introduced an accurate algorithm based on the cyclic prefix with the least mean square error compared to the similar methods to estimate the frequency offset. Like other CP-based methods, the proposed method enjoys low complexity. Considering the results, the simulations are indicated in 1000 repetitions, the suggestive algorithms are more powerful and more efficient selections compared to the existing algorithms based on the cyclic prefix especially, in the frequency-selective fading channels.

Blind Time and Frequency Synchronization Based on the Cyclic Prefix for OFDM Systems Keywords:

OFDM , Cyclic prefix , Symbol’s synchronization , Carrier frequency offset , Frequency-selective fading channels