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Method and device for estimating and correcting frequency offset of orthogonal frequency division multiplexing system

一种频偏估计、校正方法的技术，应用在多频码系统、传输系统、基带系统等方向，能够解决系统性能降低、通信质量下降、服务中断等问题

Active Publication Date: 2011-01-05
ZTE CORP
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  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

2*f d Whether it is a base station receiver or a terminal receiver, it will be a big challenge. Excessive frequency offset will cause communication quality degradation, and in severe cases, service interruption will occur, especially in high-speed mobile environments.
[0012] If the frequency offset cannot be correctly estimated and compensated, the system performance will be greatly reduced, especially when the frequency offset is large (corresponding to a high terminal movement speed) will be more obvious

Method used

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  • Method and device for estimating and correcting frequency offset of orthogonal frequency division multiplexing system
  • Method and device for estimating and correcting frequency offset of orthogonal frequency division multiplexing system
  • Method and device for estimating and correcting frequency offset of orthogonal frequency division multiplexing system

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Experimental program
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Effect test

Embodiment 1

[0122] Embodiment 1, implementation of the branch flow of the history smoothing method.

[0123] When Count (m) >Count Thr When , the historical smooth frequency offset calculation method is used to estimate and compensate the data. Use historical frequency deviation value Participate in the current residual frequency offset calculation, the initial value It comes from the last frequency offset estimation output, if there is no last time (this situation appears in Count Thr = 0), then the initial value is

[0124] This residual frequency offset ΔΔf ka Calculated by the following formula:

[0125] ΔΔ f s , ka = ∠ ( H ‾ 2 , s , ka ...

Embodiment 2

[0155] Embodiment 2, implementation of the branch flow of the multi-way trial and error method.

[0156] When Count (m) ≤Count Thr When , perform multi-branch frequency offset estimation and compensation, and calculate the initial value of the historical smooth frequency offset calculation method.

[0157] In the Z branches, use different branch initial frequency offset values g=1, L, Z, participate in the current residual frequency offset calculation, this initial value is the set value, which can be determined by simulation, and the value of Z can be set according to the capability of the receiver;

[0158] This residual frequency offset ΔΔf ka for

[0159] ΔΔ f s , ka = ∠ ( H ‾ 2 , s ...

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Abstract

The invention discloses a method and a device for estimating and correcting the frequency offset of an orthogonal frequency division multiplexing system. The method comprises the following steps of: acquiring a pilot frequency domain channel estimation value of a target user and performing sectional smoothing; judging whether to adopt a historic smoothing method or a multi-branch trial method to perform frequency offset estimation and frequency offset compensation according to a link quality state; after the frequency offset compensation, acquiring channel quality parameters of demodulation data; updating the link quality state of a receiver according to the parameters of the link quality state; determining the output value of the frequency offset estimation; and outputting a historic frequency offset value used in the next frequency offset estimation according to the determined output value of the frequency offset estimation. The method and device for estimating and correcting the frequency offset greatly enlarge the capacity range of base stations and terminals for the frequency offset estimation and the frequency offset compensation, so that the receiver can accurately and stably correct the frequency offset. Communication service quality is guaranteed reliably particularly when large frequency offset exists in high-speed mobile environmental links.

Description

technical field [0001] The invention relates to the field of mobile communication, in particular to a method and device for frequency offset estimation and correction of an orthogonal frequency division multiplexing system in the mobile communication field. Background technique [0002] The LTE project is the largest new technology research and development project launched by 3GPP in the past two years. It improves and enhances the 3G air access technology. Compared with 3G, LTE (Long Term Evolution, long-term evolution) has more technical advantages, which are reflected in higher user data rate, packet transmission, reduced system delay, improved system capacity and coverage, and reduced operating costs. [0003] The LTE downlink adopts OFDM (Orthogonal Frequency Division Multiplexing) technology. OFDM has the characteristics of high spectrum utilization and anti-multipath interference. The OFDM system can effectively resist the impact of wireless channels. The LTE uplink ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04L27/38H04L25/02
CPCH04L25/0232H04L27/2657H04L25/022H04L27/2695
Inventor 李萍曾召华秦洪峰孙维菊韩露佳雷杰
Owner ZTE CORP
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