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WO2009082849A1 - Procédé et appareil d'estimation de canal - Google Patents

Procédé et appareil d'estimation de canal Download PDF

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Publication number
WO2009082849A1
WO2009082849A1 PCT/CN2007/003878 CN2007003878W WO2009082849A1 WO 2009082849 A1 WO2009082849 A1 WO 2009082849A1 CN 2007003878 W CN2007003878 W CN 2007003878W WO 2009082849 A1 WO2009082849 A1 WO 2009082849A1
Authority
WO
WIPO (PCT)
Prior art keywords
filtering
channel
channel estimation
channel response
frequency domain
Prior art date
Application number
PCT/CN2007/003878
Other languages
English (en)
Chinese (zh)
Inventor
Feng Bi
Original Assignee
Zte Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zte Corporation filed Critical Zte Corporation
Priority to CN200780100641.2A priority Critical patent/CN101803319B/zh
Priority to PCT/CN2007/003878 priority patent/WO2009082849A1/fr
Publication of WO2009082849A1 publication Critical patent/WO2009082849A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/022—Channel estimation of frequency response
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0224—Channel estimation using sounding signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only

Definitions

  • the present invention relates to a channel estimation technique in an Orthogonal Frequency Division Multiplexing (OFDM) system, and in particular to a channel estimation method and apparatus.
  • OFDM Orthogonal Frequency Division Multiplexing
  • ISI Inter Symbol Interference
  • the OFDM technology is effective in suppressing inter-symbol interference and is therefore widely used. Due to the orthogonality requirements of OFDM for each subcarrier, the transmitting and receiving sides of the OFDM system must be strictly synchronized, and there must be sufficiently accurate channel estimation. Due to the time-varying nature of wireless channels, most OFDM systems use pilot subcarrier-based channel estimation methods.
  • the pilot subcarrier-based channel estimation method is one of the most commonly used channel estimation methods in OFDM systems.
  • the so-called pilot is for some special data, the location and value of the data are known at the transmitting end, the data is inserted into the original data according to certain principles, and then IFFT (inverse Fast Fourier Transform) is performed along with the original data. ) Transform.
  • IFFT inverse Fast Fourier Transform
  • the channel is roughly estimated by inserting a known pilot subcarrier, and then the full response of the channel is obtained by some processing means, thereby equalizing the received signal.
  • FFT Fast Fourier Transform
  • the channel estimation method currently used only performs interpolation processing in the frequency domain when performing channel estimation, and it is difficult to further improve channel estimation performance due to the presence of noise.
  • the present invention has been made in view of the problem that it is difficult to improve channel estimation performance in the channel estimation method of the related art. To this end, the present invention is directed to a channel estimation method and apparatus capable of further improving channel estimation performance by rationally adjusting, making full use of filtering, channel environment, and the like without relying on existing channel estimation algorithms. .
  • a channel estimation method includes the following processing: a filtering method for determining a channel response estimate by a channel estimation algorithm for a coherent bandwidth or a coherent time or a signal to interference and noise ratio or any combination of the three; a channel response using a pilot subcarrier position
  • the estimated value is filtered according to the determined filtering manner, wherein the filtering manner includes: frequency domain filtering, time domain filtering, frequency domain and time domain filtering; and detecting data according to the filtered channel response estimation value.
  • the operation of determining the filtering manner of the channel estimation response value is specifically: when the channel estimation algorithm has low sensitivity to the coherent bandwidth or the coherence time or the signal to interference and noise ratio or any combination of the three, the channel response estimation value is frequency-frequency. Domain filtering; time-domain filtering of channel response estimates when the channel estimation algorithm is sensitive to coherent bandwidth or coherent time or signal-to-noise ratio or any combination of the three; when the channel estimation algorithm is coherent bandwidth or coherent When the time or signal to interference and noise ratio or the sensitivity of any combination of the three is moderate, the channel response estimate is subjected to frequency domain filtering and time domain filtering.
  • a channel estimation apparatus configured to determine a channel response estimation value according to a channel estimation algorithm for a coherent bandwidth or a coherence time or a signal to interference and noise ratio or a sensitivity of any combination of the three
  • the filter is configured to determine, according to the filtering mode, the filtering mode determined by the module, and uses the channel response estimated value of the pilot subcarrier position to perform filtering; and the detecting module is configured to detect the data according to the filtered channel response estimated value of the filter.
  • the filter when the channel estimation algorithm has low sensitivity to coherent bandwidth or coherence time or signal to interference and noise ratio or any combination of the three, the filter performs frequency domain filtering on the channel response estimate; when the channel estimation algorithm is for coherent bandwidth or When the coherence time or the signal to interference and noise ratio or the sensitivity of any combination of the three is high, the filter performs time domain filtering on the channel response estimate; when the channel estimation algorithm is for coherent bandwidth or coherent time or signal to interference and noise ratio or three When the sensitivity of any combination is moderate, the filter performs frequency domain filtering and time domain filtering on the channel response estimates.
  • the frequency domain filtering operation performed by the filter is specifically: performing frequency domain filtering by using channel estimation estimates of all pilot subcarrier positions in the OFDM symbol;
  • the frequency domain filtering and the time domain filtering operation performed by the filter are specifically: first performing frequency domain filtering, preserving the channel response estimation value of all pilot subcarrier positions and the most intermediate subcarrier between every two adjacent pilot subcarriers The channel response estimate of the location, and clearing the channel response estimate of the other subcarrier locations, and then performing time domain filtering; or, first performing time domain filtering, preserving the channel response estimates for all pilot subcarrier locations and every two The channel response estimate of the most intermediate subcarrier position between adjacent pilot subcarriers, and the channel response estimate of the other subcarrier locations is cleared, and then frequency domain filtering is performed.
  • the performance of the channel estimation can be further improved by selecting a corresponding filtering manner according to the sensitivity of the channel estimation algorithm to the coherent bandwidth, excluding the dependence on the existing channel estimation algorithm.
  • FIG. 1 is a flowchart of a channel estimation method according to an embodiment of the method of the present invention
  • FIG. 2 is a detailed processing flowchart of a channel estimation method according to an embodiment of the method of the present invention
  • FIG. 3 is a diagram of an apparatus according to the present invention.
  • the present invention aims to provide a channel estimation method and apparatus for adaptively improving channel estimation performance, which are properly adjusted, Fully utilize the factors such as filtering and channel environment to further improve the performance of channel estimation, especially for the case where the channel estimation cannot further improve the performance due to the presence of noise in the OFDM system.
  • the preferred embodiments of the present invention are described with reference to the accompanying drawings, and the preferred embodiments of the present invention are intended to illustrate and explain the invention.
  • Method Embodiments According to an embodiment of the present invention, a channel estimation method is provided. As shown in FIG.
  • the method includes the following processing (step S102 - step S106): Step S102, determining a channel response estimate according to a sensitivity of a channel estimation algorithm to a coherent bandwidth or a coherent time or a signal to interference and noise ratio or any combination of the three. Filtering of the value; Step S104, filtering according to the filtering method determined by the step S102, using the channel response estimation value of the pilot subcarrier position, wherein the filtering manner includes: frequency domain filtering, time domain filtering, frequency domain and time domain filtering Step S106, detecting data according to the filtered channel response estimation value.
  • the sensitivity of the channel estimation algorithm to the coherent bandwidth is determined according to the path delay.
  • the path delay is inversely proportional to the coherence bandwidth. When the path delay is large, the coherence bandwidth is small, that is, the pilot spacing in the frequency direction is small. That is, the channel estimation algorithm is coherent
  • step S204-2 frequency domain filtering is performed on the channel response estimate (step S204-2); in this case, using OFDM symbols
  • the channel response estimates of all pilot subcarrier positions are subjected to frequency domain filtering; the pilot subcarriers of each OFDM symbol are samples of channel response, and when frequency domain filtering is used, since the pilot subcarrier spacing is N/, Therefore, if the coherence bandwidth of the channel is greater than N/, the estimation of the channel can be completed more accurately.
  • step S204-2 when the channel estimation algorithm is highly sensitive (ie, sensitive) to the coherent bandwidth, time-domain filtering the channel response estimate (step S204-2); this is because, for example, when it is required to cover a far-reaching area, After the frequency domain filtering, the change of the channel response in the interval is not accurately reflected, especially in the frequency domain direction, the channel response cannot be tracked in time and dynamically. Therefore, the scheme selection provided by the embodiment of the present invention is changed to the time. The domain performs time domain filtering.
  • the channel response estimation is subjected to frequency domain filtering and time domain filtering (step S204-6).
  • frequency domain filtering may be performed first, the channel response estimation value of all pilot subcarrier positions and the channel response estimation value of the most intermediate subcarrier position between every two adjacent pilot subcarriers are reserved, and other sub- The channel response estimate of the carrier position is cleared; then time domain filtering is performed; or, further, 4 time domain filtering may be used to preserve the 4-channel response estimate of all pilot subcarrier positions and every two adjacent pilots.
  • the channel response estimate of the most intermediate subcarrier position between the carriers, and the channel response estimate for the other subcarrier locations is cleared; then frequency domain filtering is performed. Thereafter, the data is detected based on the filtered channel response estimated value (step S206).
  • a channel estimation apparatus is provided. As shown in FIG. 3, the apparatus includes: a filtering mode determining module 302, a filter 304, and a detecting module 306. The various components described above will be further described below in conjunction with the drawings.
  • the filtering mode determining module 302 is configured to filter the channel response estimation value by using the channel estimation algorithm for the coherent bandwidth or the coherence time or the signal to interference and noise ratio or the sensitivity of any combination of the three.
  • the filter 304 is configured to filter according to the channel response estimation value of the pilot subcarrier position according to the filtering mode determined by the filtering mode determining module 302.
  • the filter when the channel estimation algorithm has low sensitivity to coherent bandwidth or coherence time or signal to interference and noise ratio or any combination of the three, the filter performs frequency domain filtering on the channel response estimate; when the channel estimation algorithm is for coherent bandwidth or When the coherence time or the signal to interference and noise ratio or the sensitivity of any combination of the three is high, the filter performs time domain filtering on the channel response estimate; when the channel estimation algorithm is for coherent bandwidth or coherent time or signal to interference and noise ratio or three When the sensitivity of any combination is moderate, the filter performs frequency domain filtering and time domain filtering on the channel response estimates.
  • the filtering mode determining module 302 may be independent of the filter 304 or may be built in the filter 304.
  • the filtering operation performed by the filter 304 is specifically: performing frequency domain filtering by using channel estimation estimates of all pilot subcarrier positions in the OFDM symbol;
  • the filter 304 is specifically: performing frequency domain filtering by using channel estimation estimates of all pilot subcarrier positions in the OFDM symbol;
  • the filtering operation performed by the filter 304 is specifically: first performing frequency domain filtering, preserving the channel response estimation values of all pilot subcarrier positions and every two adjacent pilot subcarriers.
  • the channel response estimate between the most intermediate subcarrier positions, and the channel response estimate of the other subcarrier positions is cleared, and then time domain filtering is performed; or, first, time domain filtering is performed, and all pilot subcarrier positions are reserved.
  • the channel response estimate and the channel response estimate of the most intermediate subcarrier position between every two adjacent pilot subcarriers, and the channel response estimates for the other subcarrier locations are cleared, followed by frequency domain filtering.
  • the detecting module 306 is configured to detect data according to the channel response estimated value filtered by the filter 304.
  • the channel estimation is simple and easy to implement, and does not depend on the existing channel estimation algorithm, which solves the problem that channel estimation cannot further improve performance due to the presence of noise, and provides a new adaptive improvement channel estimation performance.
  • Program The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and the present invention may be variously modified and changed. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Noise Elimination (AREA)

Abstract

L'invention porte sur un procédé et un appareil d'estimation de canal. Le procédé comprend les opérations suivantes : une manière de filtrer pour une valeur d'estimation de réponse de canal est déterminée sur la base d'une sensibilité qui est un calcul d'estimation de canal en fonction de la largeur de bande de cohérence ou du temps de cohérence ou du rapport signal sur interférence plus bruit (SINR) ou de n'importe quelle combinaison de ceux-ci, un filtrage est effectué en utilisant la valeur d'estimation de réponse de canal d'une position de sous-porteuse de fréquence pilote sur la base de la manière de filtrer déterminée, la manière de filtrer est un filtrage de fréquence, un filtrage temporel et un filtrage fréquence-temps, et des données sont détectées sur la base de la valeur d'estimation de réponse de canal qui est filtrée. Le procédé et l'appareil peuvent améliorer davantage la capacité d'estimation de canal.
PCT/CN2007/003878 2007-12-28 2007-12-28 Procédé et appareil d'estimation de canal WO2009082849A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN200780100641.2A CN101803319B (zh) 2007-12-28 2007-12-28 信道估计方法及装置
PCT/CN2007/003878 WO2009082849A1 (fr) 2007-12-28 2007-12-28 Procédé et appareil d'estimation de canal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2007/003878 WO2009082849A1 (fr) 2007-12-28 2007-12-28 Procédé et appareil d'estimation de canal

Publications (1)

Publication Number Publication Date
WO2009082849A1 true WO2009082849A1 (fr) 2009-07-09

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CN (1) CN101803319B (fr)
WO (1) WO2009082849A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012045244A1 (fr) * 2010-10-08 2012-04-12 中兴通讯股份有限公司 Procédé et dispositif pour réaliser une estimation de voie avec un niveau de performance élevé et un niveau de complexité réduit
US20120311134A1 (en) * 2011-06-03 2012-12-06 Roger Pantos Estimating Bandwidth Based on Server IP Address
CN120238395A (zh) * 2025-05-29 2025-07-01 苏州门海微电子科技有限公司 基于ofdm的电力线载波信号信道估计方法及装置

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106576086B (zh) * 2014-10-23 2020-01-31 华为技术有限公司 信道估计的方法及装置
CN112737988B (zh) * 2020-12-29 2023-12-05 芯翼信息科技(上海)有限公司 一种信道估计方法、装置、电子设备及存储介质

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020001352A1 (en) * 2000-06-05 2002-01-03 Richard Stirling-Gallacher Channel estimator for OFDM system
CN1340982A (zh) * 2000-08-31 2002-03-20 阿尔卡塔尔公司 用于采用速度估计器的移动无线电通信单元的接收机装置
US20040218702A1 (en) * 2003-04-11 2004-11-04 Robert Denk Method and apparatus for channel estimation in radio systems by MMSE-based recursive filtering
CN1555638A (zh) * 2001-08-07 2004-12-15 �����ɷ� 无线通信系统的导频滤波器的自适应选择
CN101076964A (zh) * 2004-12-16 2007-11-21 摩托罗拉公司 具有扩展信道带宽的信道估计器

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020001352A1 (en) * 2000-06-05 2002-01-03 Richard Stirling-Gallacher Channel estimator for OFDM system
CN1340982A (zh) * 2000-08-31 2002-03-20 阿尔卡塔尔公司 用于采用速度估计器的移动无线电通信单元的接收机装置
CN1555638A (zh) * 2001-08-07 2004-12-15 �����ɷ� 无线通信系统的导频滤波器的自适应选择
US20040218702A1 (en) * 2003-04-11 2004-11-04 Robert Denk Method and apparatus for channel estimation in radio systems by MMSE-based recursive filtering
CN101076964A (zh) * 2004-12-16 2007-11-21 摩托罗拉公司 具有扩展信道带宽的信道估计器

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012045244A1 (fr) * 2010-10-08 2012-04-12 中兴通讯股份有限公司 Procédé et dispositif pour réaliser une estimation de voie avec un niveau de performance élevé et un niveau de complexité réduit
US20120311134A1 (en) * 2011-06-03 2012-12-06 Roger Pantos Estimating Bandwidth Based on Server IP Address
US8650289B2 (en) * 2011-06-03 2014-02-11 Apple Inc. Estimating bandwidth based on server IP address
CN120238395A (zh) * 2025-05-29 2025-07-01 苏州门海微电子科技有限公司 基于ofdm的电力线载波信号信道估计方法及装置

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CN101803319B (zh) 2013-03-27
CN101803319A (zh) 2010-08-11

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