Method and apparatus for synchronization of orthogonal frequency division multiplexing system frequency

A technology of orthogonal frequency division and frequency multiplexing, which is applied in the field of frequency synchronization of OFDM systems, and can solve problems such as system performance degradation and destruction of carrier orthogonality

Inactive Publication Date: 2011-01-26
FUJITSU LTD
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Problems solved by technology

The offset of the carrier frequency destroys the orthogonality between the carriers, so the performance of the system is greatly reduced

Method used

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  • Method and apparatus for synchronization of orthogonal frequency division multiplexing system frequency
  • Method and apparatus for synchronization of orthogonal frequency division multiplexing system frequency
  • Method and apparatus for synchronization of orthogonal frequency division multiplexing system frequency

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Embodiment Construction

[0042] The specific implementation manner of the present invention will be described below in conjunction with the accompanying drawings. The invention provides a method and device for estimating and compensating the frequency offset caused by the inconsistency between the transmitter crystal oscillator and the receiver crystal oscillator in an OFDM communication system. The signal of the OFDM communication system has a frame structure composed of a training symbol and a plurality of OFDM data symbols, and the OFDM data symbols are inserted with pilot codes on some subcarriers.

[0043]The schematic diagram of a typical OFDM system shown in FIG. 1 is a preferred embodiment of the present invention. In the OFDM transmitter 100, the data source 101 produces a series of constellation point symbols, and the output of the data source unit 101 performs data mapping in the data mapping and pilot code insertion unit 102, and performs subcarrier allocation and pilot code insertion . ...

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Abstract

The invention relates to a frequency synchronization method and device for an orthogonal frequency division multiplexing system, wherein a transmission end combines training symbols with a circular prefix and a plurality of data symbols added with the circular prefix and inserted with pilot frequency codes into an orthogonal frequency division multiplexing signal frame, and ends the orthogonal frequency division multiplexing signal; a receiving end performs associated operations to the circular prefix in the training symbols of the received orthogonal frequency division multiplexing signal and to the partial training symbols corresponding to the circular prefix in order to acquire fraction multiple frequency deviation; the circular prefixes of each orthogonal frequency division multiplexing symbols in the received orthogonal frequency division multiplexing signal are removed, and sliding difference associated operation is performed to the training symbols in the received orthogonal frequency division multiplexing signal and to the original training symbols to acquire the integer multiple frequency deviation; the pilot frequency codes of at least two continuous data symbols in the received orthogonal frequency division multiplexing signal are performed by the associated operations to acquire residual frequency deviation.

Description

technical field [0001] The invention relates to the field of broadband wireless access, in particular to a frequency synchronization technology of an Orthogonal Frequency Division Multiplexing (OFDM) system, specifically a frequency synchronization method and device for an Orthogonal Frequency Division Multiplexing (OFDM) system. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) system has been widely used as a modulation and multiple access technique for more than 20 years, and it is a well-known transmission technique with high spectral efficiency, which is able to counteract the severe channel degradation. OFDM technology achieves the elimination of high-dispersion wireless channels at a relatively low cost by dividing a single high-rate bit stream into multiple lower-rate bit streams modulated on different subcarriers. Most of the inter-symbol interference caused by high-speed transmission is eliminated. [0003] However, there are several...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26
Inventor 欧阳琴周华
Owner FUJITSU LTD
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