A frequency domain synchronization signal transmission and detection method for OFDM system

Abstract

The invention discloses a frequency-domain synchronous signal transmission and detection method of an orthogonal frequency division multiplexing system, wherein the transmission method obtains data by IFFT (inverse fast discrete Fourier transform) operation on a PN sequence (pseudo-random sequence) The time-domain preamble training sequence of the frame; wherein the detection method utilizes a time window with the same length as the preamble training sequence to slide the received time-domain data stream, and sends the data in the window into the FFT (Fast Discrete Fourier Transform) operation After the module, use the PN sequence correlation characteristics in the frequency domain to determine whether there is a signal arriving, and obtain the precise time domain synchronization position of the signal. The frequency-domain synchronous signal transmission and detection method of the OFDM system avoids the influence of time-domain interference, and at the same time utilizes the correlation characteristics of the PN sequence in the frequency domain. In a synchronous manner, the detection accuracy of the frequency domain correlation method provided by the present invention is greatly improved. The present invention can also realize reliable signal detection and synchronization under harsh channel conditions with interference.

Description

A frequency domain synchronization signal transmission and detection method for OFDM system technical field The invention relates to the technical field of data transmission in mobile communication technology, in particular to a method for sending and detecting frequency domain synchronization signals of an orthogonal frequency division multiplexing system. Background technique Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) is a mobile communication technology that utilizes parallel transmission to improve communication data transmission rate. This technology can greatly improve the spectrum utilization rate, and also has many advantages such as anti-multipath interference and intersymbol interference, easy channel estimation and equalization, and low system implementation complexity. A key problem that needs to be solved in OFDM signal modulation and demodulation equipment is the frame synchronization problem. In a burst OF...

AI Technical Summary

Problems solved by technology

But this synchronization method has a strong dependence on channel conditions

If the channel conditions are relatively bad, there is single-tone interference or narrow-band interference, the time-domain correlation characteristics of the signal will be greatly interfered. Under such channel conditions, this time-domain correlation synchronization method is obviously unreliable

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