Novel distributed MIMO-OFDM system synchronization method based on low-signal-to-noise-ratio ZCZ sequence and mutual fuzzy function

Abstract

The invention relates to a novel distributed MIMO-OFDM system synchronization method based on a low-signal-to-noise-ratio ZCZ sequence and a mutual fuzzy function. Aiming at the problem that the synchronization performance of the distributed MIMO-OFDM system is not ideal under the condition of low signal-to-noise ratio, the invention provides a novel distributed MIMO-OFDM system synchronization method based on a low-signal-to-noise-ratio ZCZ sequence and a mutual fuzzy function. The method comprises the steps as follows: first, constructing a four-phase orthogonal ZCZ sequence and a conjugate symmetric new training sequence based on periodic extension of the four-phase orthogonal ZCZ sequence; and then, establishing a mutual fuzzy function of data signals and the new training sequence at a receiving end to acquire precise time synchronization and frequency offset estimation. Theoretical analysis and simulation show that the method is better in performance than similar synchronization methods under the signal-to-noise ratio of -10dB.

Description

technical field [0001] The invention relates to the technical field of MIMO-OFDM, in particular to a new method for synchronizing a distributed MIMO-OFDM system with low signal-to-noise ratio ZCZ sequences and mutual ambiguity functions. Background technique [0002] With the rapid development of the wireless communication field, people have higher and higher requirements for communication quality and communication speed. The future mobile communication emphasizes the need for higher transmission rate and high spectrum utilization, and the MIMO-OFDM system effectively solves the problem of meet these two requirements. OFDM technology has the advantages of good anti-multipath fading ability, high spectrum utilization rate, and high-speed transmission. MIMO technology uses multiple transmit antennas and multiple receive antennas for wireless communication transmission technology, which can obtain space multiplexing gain and space diversity gain. Effectively increase the syste...

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Problems solved by technology

The simulation results show that the time synchronization performance of this method is better under the condition of low signal-to-noise ratio, but the frequency offset is not considered

XiaoChi et al. proposed an improved carrier frequency synchronization method. This method is carried out under the assumption of precise time synchronization. At the receiving end, short-sequence correlation is used to obtain integer frequency offset estimation, and long-sequence correlation is used to obtain fractional frequency offset estimation. Simulation The results show that under the condition of low signal-to-noise ratio, the performance of frequency offset estimation is better, but the algorithm lacks the consideration of timing frequency offset.

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