Communication method and device for crossing frequency division multiple address-time division multiple address

Abstract

The invention relates to a communication method used in OFDMA-TDMA system and a relative device, wherein the system physical frame is formed by two sections of forward sequence and data marks; the first pilot sequence can avoid orthogonal modulation, as the false random sequence emitted directly, to fix the start time of DFT calculation; the second pilot sequence is orthogonally modulated with the data mark to form OFDM mark to be emitted. Compared with traditional method, the invention can avoid demodulating pilot mark at the start of DFT calculation, to effectively time the mark and improve the accuracy of evaluated valve of signal channel.

Description

technical field [0001] The present invention relates to a wireless communication method and device, especially an information transmission system using OFDM technology for wireless local area network, fixed wireless access, mobile communication, terrestrial digital TV broadcasting, etc., more specifically, the present invention relates to a symbol timing And an Orthogonal Frequency Division Multiple Access-Time Division Multiple Access communication method and device for improving channel estimation accuracy. Background technique [0002] With the gradual integration of wireless network, multimedia technology and the Internet, people have higher and higher requirements for the type and quality of wireless communication services. In order to meet the requirements of wireless multimedia and high-speed data transmission, it is necessary to develop a new generation of wireless communication system. In the new-generation wireless system, some new technologies, such as Orthogonal...

AI Technical Summary

Problems solved by technology

But this method also has some disadvantages, because when performing DFT demodulation on the received pilot and data, it is necessary to determine the initial calculation time of the DFT window according to the pilot signal

However, to determine the DFT operation time, it is necessary to perform DFT demodulation on the pilot symbols first, so there is an interdependence and influence relationship between symbol timing and DFT demodulation.

If the DFT calculation time does not correspond to the start time of the frame, that is, there is a deviation, which will affect the accuracy of subsequent operations such as timing and frequency synchronization, thereby reducing the overall performance of the system

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