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Method and apparatus for estimating OFDM system channel

A channel estimation and orthogonal frequency division technology, applied in channel estimation, multi-frequency code system, baseband system, etc., can solve the problem of large error in channel estimation

Active Publication Date: 2009-05-20
HONOR DEVICE CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The embodiment of the present invention provides a channel estimation method and device for an OFDM system, which solves the disadvantage of relatively large error in channel estimation due to edge effects of OFDM symbols in channel estimation of an OFDM system

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  • Method and apparatus for estimating OFDM system channel
  • Method and apparatus for estimating OFDM system channel
  • Method and apparatus for estimating OFDM system channel

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Embodiment 1

[0041] This embodiment provides an OFDM system channel estimation method, see image 3 shown, including:

[0042] Step 1: the receiving device receives the signal sent by the sending device;

[0043] Wherein, when the signal sent by the sending device propagates through the medium, usually the medium is air, and the signal received by the receiving device in step 1 is modified. Therefore, in order to successfully demodulate and decode the received signal, the receiving device needs to estimate the situation of the wireless channel, which is usually represented by the impulse response or transfer function of the channel.

[0044] Step 2: The receiving device performs channel estimation in the time dimension on the received signal;

[0045]Wherein, the channel estimation of the time dimension performed by the receiving device on the received signal in step 2 may adopt linear channel estimation or Wiener filter channel estimation methods in the prior art. For the specific oper...

Embodiment 2

[0063] An OFDM system channel estimation method, which is similar to the OFDM system channel estimation method provided in Embodiment 1 in implementation, and this embodiment is a more specific execution method of the method provided in Embodiment 1. The description of this embodiment is mainly based on Figure 7 The operation flow for processing the frequency domain signal shown in .

[0064] see Figure 7 shown. After the receiving device performs channel estimation in the time dimension on the received signal, and the receiving device extracts a pilot frequency on the bandwidth of the OFDM symbol obtained after performing the channel estimation in the time dimension, Figure 7 The first line in the above indicates the distribution of the OFDM symbol on the bandwidth of the pilot point and the frequency points that carry the data. The pilot point is 3 times the sampling of the OFDM symbol on the bandwidth. It should be noted that: for the pilot point The distribution sati...

Embodiment 3

[0071] This embodiment provides a receiving device, see Figure 8 As shown, it includes: a receiving unit 10, a time dimension estimation unit 20, a pilot frequency extraction unit 30, an additional pilot frequency unit 40, an inverse fast Fourier transform IFFT unit 50, a time domain windowing unit 60, a zero padding unit 70, and a fast Fourier transform FFT unit 80 and acquisition unit 90 .

[0072]Wherein, the receiving unit 10 receives the signal sent by the sending device, wherein the receiving unit 10 may specifically be a receiving antenna; the time dimension estimation unit 20 is used for performing time dimension channel estimation on the signal received in the receiving unit 10, specifically estimating The method can adopt linear channel estimation in the prior art or the method of Wiener filtering channel estimation; Pilot frequency extracting unit 30, is used for obtaining the OFDM symbol after the channel estimation of time dimension in the time dimension estimati...

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Abstract

The invention discloses an orthogonal frequency division multiplexing (OFDM) system channel estimation method. The embodiment of the invention also provides a corresponding receiving device. The technical proposal of the invention adopts the receiving device to perform channel estimation of time dimension to a received signal first, channel information of pilot points is obtained in an effective subcarrier frequency point on a frequency domain of each OFDM symbol, information of pilot points except for an effective subcarrier frequency band can be obtained by adding the information of the pilot points, and then the frequency response of a channel is obtained through IFFT conversion, window adding, zero complement and FFT conversion, namely an estimation result to the channel is obtained. The number of the pilot points is increased, thereby achieving the aims of inhibiting the edge effect and improving the accuracy of channel estimation.

Description

technical field [0001] The present invention relates to the technical field of mobile communication, in particular to a channel estimation method and device for an Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) system. Background technique [0002] OFDM technology is a high-speed multi-carrier transmission technology that can effectively combat Inter-Symbol Interference (ISI, Inter-SymbolInterference). The spectrums of the various sub-channels overlap each other, so that spectrum resources can be utilized to the maximum. OFDM technology has been successfully applied to Asymmetric Digital Subscriber Line (ADSL, Asymmetric Digital Subscriber Line), Wireless Local Loop (WLL, Wireless Local Loop), Digital Audio Broadcasting (DAB, Digital Audio Broadcasting), High Definition Television (HDTV , High-definition Television), wireless local area network (WLAN, Wireless Local Area Network) and other systems, the application of OFDM techn...

Claims

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Application Information

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IPC IPC(8): H04L27/26H04L25/03
CPCH04L25/0232H04L25/022
Inventor 花梦吴更石唐兵焦淑蓉
Owner HONOR DEVICE CO LTD
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