WO2004014029A1 - Procede d'estimation de canal dans un systeme de communication amcr a large bande - Google Patents
Procede d'estimation de canal dans un systeme de communication amcr a large bande Download PDFInfo
- Publication number
- WO2004014029A1 WO2004014029A1 PCT/CN2002/000824 CN0200824W WO2004014029A1 WO 2004014029 A1 WO2004014029 A1 WO 2004014029A1 CN 0200824 W CN0200824 W CN 0200824W WO 2004014029 A1 WO2004014029 A1 WO 2004014029A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- channel estimation
- time slot
- channel
- estimation value
- slot
- Prior art date
Links
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
- H04L25/0224—Channel estimation using sounding signals
- H04L25/0228—Channel estimation using sounding signals with direct estimation from sounding signals
Definitions
- the present invention relates to a mobile communication system, and particularly to a channel estimation method in a wideband code division multiple access (WCDMA) communication system.
- WCDMA wideband code division multiple access
- WCDMA Wideband code division multiple access
- 3GPP 3rd Generation Partnership Project Standardization Organization
- the number of pilot symbols in each slot is between 3 and 8. Therefore, which method is used to accurately estimate the pilots in the slot at the same time?
- the channel characteristics corresponding to the frequency symbol segment and the data symbol segment are very important for improving the receiving performance of the receiver in a high-speed mobile environment.
- the existing channel estimation methods mainly include the following: single-slot average channel estimation method, channel estimation method based on simplified Kalman tracking filtering, multi-slot weighted average channel estimation Methods (Weighted Multi-Slot Averaging, WMSA), Iterative Channel Estimation (ICE), and Multi-slot Averaged Linear Interpolation (MALI).
- the single-slot averaged channel estimation method has fewer pilot symbols and cannot effectively filter out the effects of noise. Therefore, the performance is poor in both low-speed and high-speed mobile environments.
- the channel estimation method based on simplified Kalman tracking filtering is an improvement of the former. The performance is improved in a low-speed mobile environment, but the performance is still poor in a high-speed mobile environment.
- the estimation process of the multi-slot weighted average channel estimation method is as follows: 1) Use the single-slot average channel estimation method to obtain the channel estimation value of each time slot; 2) Weight the combined estimates of multiple time slots to obtain Channel estimate for the current slot. Because weighted averaging is performed among multiple time slots to effectively filter out the influence of noise, the method can get good channel estimation performance in the case of slow signal fading, but as the channel deteriorates, such as the speed of movement increases, because The estimated value does not reflect the channel characteristics at different times in the time slot well, so the performance deteriorates.
- ICE iterative channel estimation
- the idea of the multi-slot average linear interpolation channel estimation method is as follows: Firstly, obtain the channel estimation value of each slot by multi-slot weighted average (WMSA), and then use the channel of the current slot and the next slot The estimated values are linearly interpolated to obtain channel estimation values corresponding to each symbol in the current slot. Because the linear channel interpolation is used to obtain the channel estimation value corresponding to each symbol in the time slot, the performance of this method is better than the multi-slot weighted average method when the channel is degraded, but it is still based on the multi-slot weighted average.
- WMSA multi-slot weighted average
- a technical task to be solved by the present invention is to propose a channel estimation method for uplink channels of a WCDMA system based on segmentation estimation in a time slot, in view of various shortcomings of the prior art in the case of channel degradation, in order to: Improve the reception performance of the message system in a mobile environment.
- the channel estimation method in the wideband code division multiple access system proposed by the present invention includes the following steps: Step 1. Descramble and despread the wideband spread spectrum signal input to the RAKE receiver;
- Step 2 Take out pilot symbols from each time slot of the dedicated physical control channel (DPCCH) according to the predicted time slot format
- Step 3 Perform a de-correlation operation on the extracted pilot symbols, each pilot symbol and a known pilot symbol to obtain a channel estimation value of each pilot symbol;
- Step 4 Perform arithmetic average of the channel estimation values of all pilot symbols in each time slot to obtain the channel estimation values of each time slot;
- Step 5 Weighted average of channel estimation values of multiple time slots before and after to obtain channel estimation values corresponding to pilot symbol segments of the current time slot;
- Step 6 Weighted average channel estimation values of multiple time slots before and after to obtain channel estimation values corresponding to data symbol segments of the current time slot;
- Step 7. Use the channel estimation value of the pilot symbol segment of the current time slot to compensate the data corresponding to the pilot symbol segment in time in the dedicated physical channel, and use the channel estimation value of the data symbol segment of the current time slot to the dedicated physical channel.
- the data corresponding to the data symbol segment in the channel is compensated in time, and the compensated data is output to the maximum ratio combining module for maximum ratio combining.
- the method for obtaining the channel estimation value of the pilot symbol segment in the time slot in the fifth step includes the following steps (assuming that the current time slot number is n): '
- the time slot is weighted and averaged according to the corresponding weights to obtain the channel estimation value of the pilot symbol segment of the time slot n.
- the method of step 6 to obtain the channel estimation value of the data symbol segment in the time slot includes the following steps (assuming the current slot number For n):
- the above time slots are weighted and averaged according to the corresponding weights to obtain the channel estimation value of the data symbol segment of the time slot n.
- FIG. 1 is a frame diagram of the uplink dedicated physical channel (DPCH) of the WCDMA system
- FIG. 2 is a schematic diagram of a conventional multi-time chirped weighted average channel estimation algorithm.
- DPCH uplink dedicated physical channel
- FIG. 3 is a schematic diagram of an application of the channel estimation method according to the present invention.
- FIG. 4 is a flowchart of a channel estimation method according to the present invention.
- FIG. 5 is a flowchart of a channel estimation value of a pilot symbol segment in a calculation slot described in FIG. 4.
- FIG. 6 is a flowchart for calculating a channel estimation value of a data symbol segment in a time slot as described in FIG. 4.
- Figure ⁇ is an embodiment of the channel estimation algorithm according to the present invention. Best practice
- FIG. 2 is a schematic diagram of a conventional multi-slot weighted average channel estimation algorithm.
- a multi-slot weighted average channel estimation method needs to be used to calculate the channel estimation value of time slot 2.
- the specific process is as follows: Firstly, time slot 1 is obtained by arithmetically averaging the channel estimation values of each pilot symbol in the time slot. , 2, 3, and 4 channel estimates, and then weighted average between four adjacent time slots according to the weights corresponding to each time slot in the figure, to obtain the final channel estimation value of time slot 2,
- the AD converter 301 converts the analog signal input to the receiver into a digital signal and sends it to the descrambling and despreading module 304, and the descrambling and despreading module 304 Descramble and despread the input signal using each multipath scrambling code generated by the code tracker 302 and the code generator 303, and descramble and despread each multipath signal Send it to its corresponding channel estimation and compensation module 305.
- the channel estimation and compensation module 305 calculates the channel estimation value of the pilot frequency band and data segment in each time slot and compensates the dedicated channel. The compensated signals of each path are output to the maximum.
- the ratio combining module 306 performs maximum ratio combining, and finally inputs the combined signal into the deinterleaving / decoder 307 for deinterleaving and decoding to obtain the original signal transmitted by the transmitting end.
- the channel estimation method based on the intra-time slot estimation in the present invention is the channel estimation and compensation module 305.
- FIG. 4 is a flowchart of an uplink channel estimation method using the present invention. This logic flow starts at step 401 and ends at step 407.
- Step 401 performs descrambling and spreading on the wideband spread spectrum signal input to the RAKE receiver.
- step 402 pilot symbols are taken from each time slot of the dedicated physical control channel (DPCCH) according to a predetermined time slot format.
- DPCCH dedicated physical control channel
- step 403. Correlation processing is performed on the extracted pilot symbols and each pilot symbol to obtain a channel estimation value of each pilot symbol.
- step 404 the channel estimation values of all pilot symbols in each time slot are arithmetically averaged to obtain the channel estimation values of each time slot.
- step 405 the channel estimation values of multiple time slots before and after are weighted and averaged to obtain the channel estimation values corresponding to the current time slot pilot symbol segment;
- Step 406 is sequentially performed, and channel estimation values of multiple time slots before and after are weighted and averaged to obtain channel estimation values corresponding to the current time slot data symbol segment;
- step 407 the dedicated channel of the current slot is compensated according to the channel estimation value of the pilot symbol segment and the data symbol segment, and the compensation result is output for maximum ratio combining.
- FIG. 5 is a flowchart of calculating a channel estimation value of a pilot symbol segment in a time slot in the channel estimation method according to the present invention, and is a detailed step 405.
- the logic flow starts at step 501 and ends at step 503.
- Step 501 takes the channel estimation values of timeslots n-k, n-k + 1, ..., n, ..., n + k-1, n + k obtained in step 404 (generally, k takes 1).
- step 502 the corresponding weights of the above time slots are set as
- step 503 the above timeslots are weighted and averaged according to corresponding weights to obtain the channel estimation value of the pilot symbol segment of timeslot n, that is,
- FIG. 6 is a flowchart of calculating a channel estimation value of a data symbol segment in a time slot in the channel estimation method according to the present invention, and is a refinement of step 406. The logic flow starts at step 601 and ends at step 603.
- Step 601 takes the channel estimates n-k + l, ...,. N, n + 1, ..., n + k obtained from step 404 (in general, k takes I
- step 602 the weights corresponding to the above time slots are respectively set to ⁇ •• "" " ⁇ •• ⁇ .
- step 603 The sequence proceeds to step 603, and the above timeslots are weighted and averaged according to corresponding weights to obtain timeslot n data.
- the channel estimation value of the symbol segment that is,
- Fig. 7 is an embodiment of a channel estimation algorithm according to the present invention. In this embodiment, the channel estimation method proposed by the present invention is used to calculate the channel estimation value of time slot 2.
- the time slot 1 is obtained by arithmetically averaging the channel estimation values of each pilot symbol in the time slot.
- Channel estimates of 1, 2, 3, and 4 and then weighted average between adjacent timeslots 1, 2, and 3 according to the weights corresponding to each timeslot in the figure to obtain the final channel estimate of the pilot frequency band of timeslot 2,
- ⁇ is the channel estimation value, respectively, in each time slot arithmetic average and weight obtained when a multi-slot of each slot corresponding to a weighted average value.
- the above parameter settings are also convenient for hardware implementation.
- a channel estimation method based on segmented estimation within a time slot can be used to accurately obtain the Channel estimation values of frequency bands and data segments can reflect the change of channel characteristics in different time periods in a time slot when the channel is fading quickly, thereby greatly improving the reception performance of the communication system in a high-speed mobile environment.
- this method can effectively utilize the symmetry principle and accurately estimate the channel characteristics corresponding to the pilot symbol segment and the data symbol segment in a time slot, thereby truly avoiding the existing algorithms that cannot accurately estimate
- the shortcomings of the channel characteristics corresponding to different periods in the slot improve the reception performance of the WCDMA system in a high-speed mobile environment.
- the channel estimation method based on the segmentation estimation in the time slot proposed by the present invention can accurately estimate the channel characteristics corresponding to the pilot symbol segment and the data symbol segment in a slot at the same time due to the good use of the symmetry principle This avoids the disadvantage that other algorithms cannot accurately estimate the channel characteristics corresponding to different periods in a time slot, thereby improving the reception performance of the communication system in a high-speed mobile environment.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
- Monitoring And Testing Of Transmission In General (AREA)
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT02782643T ATE550856T1 (de) | 2002-08-06 | 2002-11-18 | Verfahren zur kanalschätzung bei breitbandiger cdma-kommunikation |
AU2002349441A AU2002349441A1 (en) | 2002-08-06 | 2002-11-18 | A method of channel estimation in wideband cdma communication |
EP02782643A EP1560388B1 (en) | 2002-08-06 | 2002-11-18 | A method of channel estimation in wideband CDMA communication |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN02136444 | 2002-08-06 | ||
CN02136444.3 | 2002-08-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2004014029A1 true WO2004014029A1 (fr) | 2004-02-12 |
Family
ID=31194486
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/CN2002/000824 WO2004014029A1 (fr) | 2002-08-06 | 2002-11-18 | Procede d'estimation de canal dans un systeme de communication amcr a large bande |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1560388B1 (zh) |
AT (1) | ATE550856T1 (zh) |
AU (1) | AU2002349441A1 (zh) |
WO (1) | WO2004014029A1 (zh) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7209510B2 (en) * | 2004-07-20 | 2007-04-24 | Skyworks Solution, Inc. | Channel estimation system for a wideband code division multiple access (WCDMA) communication system |
US8295328B2 (en) | 2006-10-11 | 2012-10-23 | Telefonaktiebolaget Lm Ericsson (Publ) | Doppler frequency control of G-rake receiver |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999031835A1 (fr) * | 1997-12-18 | 1999-06-24 | Ntt Mobile Communications Network Inc. | Dispositif d'estimation de voie, recepteur amcr et emetteur/recepteur amcr comprenant ledit dispositif |
WO2000036760A1 (en) * | 1998-12-16 | 2000-06-22 | Telefonaktiebolaget Lm Ericsson (Publ) | Channel estimation for a cdma system using pre-defined symbols in addition to pilot symbols |
CN1288316A (zh) * | 1999-11-12 | 2001-03-21 | 深圳市中兴通讯股份有限公司 | 一种基于***导频符号的相干信道估计方法 |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1270445C (zh) * | 1999-04-02 | 2006-08-16 | 株式会社Ntt杜可莫 | 信道估计装置和方法以及解调装置和方法 |
-
2002
- 2002-11-18 AU AU2002349441A patent/AU2002349441A1/en not_active Abandoned
- 2002-11-18 EP EP02782643A patent/EP1560388B1/en not_active Revoked
- 2002-11-18 WO PCT/CN2002/000824 patent/WO2004014029A1/zh not_active Application Discontinuation
- 2002-11-18 AT AT02782643T patent/ATE550856T1/de active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999031835A1 (fr) * | 1997-12-18 | 1999-06-24 | Ntt Mobile Communications Network Inc. | Dispositif d'estimation de voie, recepteur amcr et emetteur/recepteur amcr comprenant ledit dispositif |
WO2000036760A1 (en) * | 1998-12-16 | 2000-06-22 | Telefonaktiebolaget Lm Ericsson (Publ) | Channel estimation for a cdma system using pre-defined symbols in addition to pilot symbols |
CN1288316A (zh) * | 1999-11-12 | 2001-03-21 | 深圳市中兴通讯股份有限公司 | 一种基于***导频符号的相干信道估计方法 |
Also Published As
Publication number | Publication date |
---|---|
EP1560388B1 (en) | 2012-03-21 |
EP1560388A4 (en) | 2006-05-31 |
EP1560388A1 (en) | 2005-08-03 |
AU2002349441A1 (en) | 2004-02-23 |
ATE550856T1 (de) | 2012-04-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP3872647B2 (ja) | チャネル推定装置および方法、復調装置および方法、ならびにフェージング周波数判定装置および方法 | |
US7688907B2 (en) | Method for channel estimation in orthogonal frequency division multiplexing system and device thereof | |
US6414988B1 (en) | Amplitude and phase estimation method in a wireless communication system | |
JP3805520B2 (ja) | 移動通信における速度推定装置および方法 | |
US7352829B2 (en) | Data-aided channel estimation | |
CN100568784C (zh) | 利用多时隙平均内插进行信道估计的方法和*** | |
JP2008503125A (ja) | 受信信号品質推定のための良性干渉抑制 | |
KR20030074746A (ko) | 파일럿 및 비파일럿 데이터를 이용하여 채널 특성을추정하는 방법 및 장치 | |
JPH11502098A (ja) | 通信システムにおけるチャネル推定の改善 | |
JP2003503933A (ja) | 改良型パイロットチャネルを有する符合分割多重アクセスシステム | |
JP2005518752A (ja) | 無線受信機でのチャネル推定 | |
US8422354B2 (en) | Channel estimation method and apparatus using data channel | |
JP3875634B2 (ja) | 速度に適応したチャネルを推定するための方法および装置 | |
JP2001358613A (ja) | Cdma受信装置 | |
JP4588931B2 (ja) | 移動無線端末 | |
CN1474528A (zh) | 宽带码分多址通信***中信道估计方法 | |
JP2003522466A (ja) | 通信システムの送信電力制御方法 | |
WO2004014029A1 (fr) | Procede d'estimation de canal dans un systeme de communication amcr a large bande | |
CN1543106A (zh) | 用于宽带码分多址通信***的信道估计方法 | |
Ling et al. | Analysis of performance and capacity of coherent DS-CDMA reverse link communications | |
WO2002021711A1 (fr) | Procede d'evaluation de voie et systeme de reception permettant la mise en oeuvre dudit procede | |
JP2003069451A (ja) | Cdma受信機 | |
JP2001244914A (ja) | 信号対雑音干渉電力比推定装置 | |
CA2727686C (en) | Channel estimation device and method, demodulation device and method, and fading frequency decision device and method | |
JP2003258928A (ja) | 復調装置および復調方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LU MC NL PT SE SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2002782643 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 2002782643 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: JP |
|
WWW | Wipo information: withdrawn in national office |
Country of ref document: JP |