Frame synchronizing technology for erthogonal frequency division multiplex system frame

A technology of orthogonal frequency division and system frame, applied in the direction of orthogonal multiplexing system, transmission system, synchronization device, etc., can solve the problem of character deterioration

Inactive Publication Date: 2005-08-24
INST OF SEMICONDUCTORS - CHINESE ACAD OF SCI
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  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

The Maximum Correlation Criterion (MC) deteriorates significantly in the case of multipath Rayleigh fading channel transmission or non-constant envelope modulation techniques

Method used

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  • Frame synchronizing technology for erthogonal frequency division multiplex system frame
  • Frame synchronizing technology for erthogonal frequency division multiplex system frame
  • Frame synchronizing technology for erthogonal frequency division multiplex system frame

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Embodiment Construction

[0021] The invention relates to a method for frame synchronization of an OFDM system. The timing metric is defined as the square of the cumulative ratio of two variables, the numerator variable is the modulus of the product of the received signal and its delayed complex conjugate signal, and the denominator is is the instant power of the training symbols, and this frame synchronization technique is applicable to all OFDM systems that allow cyclic training symbols to be added at the front end of the data frame, including the following steps:

[0022] 1) Select the length of receiving signal delay and related operation;

[0023] 2) Calculate the energy of the training symbols within the correlation length;

[0024] 3) Set the expected value of the timing sequence at the correct timing moment according to the results of the Monte Carlo experiment or the conclusions derived from the theory;

[0025] 4) Calculate the packet detection decision threshold according to the expected va...

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Abstract

A frame synchronization method of orthogonal frequency compound system. The timing list is defined as square of two variables adding ratio, the numerator variable is the module value of the receiving signal and compound signal, the denominator is the instant power of training symbol. This frame synchronization technology is suitable for all orthogonal frequency system allowing adding circular training symbol at the front end of the data frame. It includes the following processes: 1) choose the delay of the receiving signal and the length of relative calculation; 2) calculate the energy of the relative length training symbol; 3) according Monte Carlo result or theoretical results set the expected value of the timing order at the right time; 4) according the expected value of the timing order at the wrong time and the artificial valve value calculate the valve value including test and judgment; 5)calculate the timing list of the receiving data and judge the startup time according to the valve value.

Description

technical field [0001] The invention relates to a frame synchronization technology, in particular to a frame synchronization method of an Orthogonal Frequency Division Multiplexing (OFDM) system. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) is a high-speed broadband transmission technology in a wireless environment. In view of the frequency selective response of wireless channels, the main idea of ​​OFDM technology is to divide a given channel into multiple sub-channels in the frequency domain, use a sub-carrier for modulation on each sub-channel, and transmit sub-carrier sequences in parallel, so The frequency response of the sub-channel is relatively flat, and the signal bandwidth is smaller than the relevant bandwidth of the channel, which greatly reduces the inter-symbol interference; the sub-carrier spectrums covering each other will not interfere with each other due to the orthogonal nature, which improves the spectrum utilization of ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04J11/00H04L7/00
Inventor 刘扬石寅
Owner INST OF SEMICONDUCTORS - CHINESE ACAD OF SCI
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