Time synchronization method and device for frequency hopping orthogonal frequency division multiplexing system

Abstract

The invention relates to a time synchronization method and a time synchronization device for a frequency hopping orthogonal frequency division multiplexing system, and belongs to mobile communication systems. The time synchronization method comprises the following steps of: 1, performing envelope detection on orthogonal frequency division multiplexing data sampled and reconstructed by an analog to digital converter by utilizing data segmentation and pulse group sliding window to obtain a data packet; 2, accurately positioning the windowing position of a fast Fourier transform (FFT) window of the data packet by using the detection method of a matched filtering FFT window having a maximum weight tap; 3, after the windowing position of the FFT window of the data packet is determined, determining a frequency range to which each received orthogonal frequency division multiplexing (OFDM) symbol belongs by using multi-band detection; and 4, after the frequency ranges to which the OFDM symbols belong are determined, sequentially judging whether the current received OFDM symbols are a packet synchronization sequence or a frame synchronization sequence by using a preamble. By the method, the time synchronization solution, which is sensitive and accurate, has simple hardware structure and is easy to realize, is provided.

Description

technical field [0001] The invention relates to the technical field of mobile communication, in particular to a time synchronization method and device for a frequency hopping orthogonal frequency division multiplexing system. Background technique [0002] With the development of science and technology and the continuous improvement of people's living standards, wireless communication technology plays an increasingly important role in people's daily work and life. Good wireless communication technology to maintain timely exchange and smooth flow of information. At present, the second-generation digital mobile communication system has been widely used in the world, and its data transmission rate is 9.6kbit / s, up to 32kbit / s. The data transmission rate of the third generation mobile communication system can reach 2Mbit / s. In order to further realize high-quality, high-speed mobile communication services, theoretical and technical research on fourth-generation mobile communica...

AI Technical Summary

Problems solved by technology

In addition, the sampling frequency of the analog-to-digital converter and digital-to-analog converter between the transmitter and receiver will be inconsistent due to the inconsistency of the sending and receiving end device technology, power supply voltage, temperature and other factors. Division multiplexing technology system performance also has an important impact

[0006] To sum up, frequency-hopping OFDM broadband systems, such as ultra-wideband systems, occupy a very large spectrum bandwidth, which means that the operating frequency of the analog-to-digital converter is also very high, up to 528MHz, which has a great impact on the power consumption of portable terminals. Sensitive challenges are very large; in addition, the system adopts frequency hopping technology, the preamble sequence collected by the receiving end before synchronization is only a part of the sending end; and the multipath effect of the wireless environment is very large, plus carrier frequency offset, sampling frequency offset, etc. Ideal factor, the preamble sequence used for synchronization is relatively distorted at the receiving end

Under such conditions, once a timing synchronization error occurs, it will cause packet leakage or misconnection.

Especially for real-time communication systems, this will be a serious error

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