关键词: 多输入多输出, 正交频分复用, 定时同步, 恒幅零自相关码

Abstract:

A time synchronization method using shift-orthogonal Constant Amplitude Zero Auto Correlation (CAZAC) sequences constructing the time synchronization preamble is designed for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. Owning to the unique properties of the designed synchronization preamble, the use of a symmetrical-correlator at the receivers can generate unit pulses for different transmitters to detect the time offsets of each antenna element. The performance of the proposed is compared with traditional methods on the condition of different time offsets in simulations, it can be found that the proposed scheme will provide higher accuracy than that caused by the distributed transmitters when detecting the different time offsets.

Key words: multiple-input multiple-output, orthogonal frequency division multiplexing, time synchronization, constant amplitude zero auto correlation