CN1141816C - Multipath signal processing method with slow path search and multi-window fast channel estimation - Google Patents

Multipath signal processing method with slow path search and multi-window fast channel estimation Download PDF

Info

Publication number
CN1141816C
CN1141816C CNB011367253A CN01136725A CN1141816C CN 1141816 C CN1141816 C CN 1141816C CN B011367253 A CNB011367253 A CN B011367253A CN 01136725 A CN01136725 A CN 01136725A CN 1141816 C CN1141816 C CN 1141816C
Authority
CN
China
Prior art keywords
window
fast
channel
multipath
estimation
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Fee Related
Application number
CNB011367253A
Other languages
Chinese (zh)
Other versions
CN1347223A (en
Inventor
赵春明
王玲
蒋良成
黄鹤
程时昕
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southeast University
Research Institute of Telecommunications Transmission of Ministry Information Industry
Original Assignee
Southeast University
Research Institute of Telecommunications Transmission of Ministry Information Industry
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 Southeast University, Research Institute of Telecommunications Transmission of Ministry Information Industry filed Critical Southeast University
Priority to CNB011367253A priority Critical patent/CN1141816C/en
Publication of CN1347223A publication Critical patent/CN1347223A/en
Priority to PCT/CN2002/000740 priority patent/WO2003036839A1/en
Application granted granted Critical
Publication of CN1141816C publication Critical patent/CN1141816C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H04B1/709—Correlator structure
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J13/00—Code division multiplex systems
    • H04J13/0007—Code type
    • H04J13/0022—PN, e.g. Kronecker

Abstract

The present invention combines slow path search and fast channel estimation based on a fast estimation (sub) window, solves the problem of performance reduction when paths are frequently switched in traditional methods, and simultaneously and greatly reduces computational complexity without reducing channel estimation performance. The implementation of the present invention is carried out according to the following steps: slow path search, fast channel estimation based on the quick estimation (sub) window, fast channel estimation as well as new slow effective arrival path search carried out in a protective window. The present invention can form multi-path channel estimators with excellent performance and low computational complexity for CDMA systems.

Description

Multipath signal processing method and device that slow path search and multi-window fast channel are estimated
Technical field
The present invention relates to multipath signal processing method and device that slow path search in CDMA (code division multiple access) the cellular mobile communication field, particularly CDMA mobile communication system and multi-window fast channel are estimated.
Background technology
The multipath fading phenomenon that mobile communication system exists can cause the serious multipath of system to disturb.In CDMA (code division multiple access) cell mobile communication systems that uses spread spectrum, pilot tone (Pilot) signal that contains the information of knowing by reception, amplitude and phase place to multipath signal are estimated, thereby are made the time domain diversity and the coherent reception of multipath signal become possibility.Thisly carry out the relevant band spread receiver that the time domain diversity handles at multipath fading signal and be called the RAKE coherent receiver.
For obtaining RAKE receptivity preferably, except must realize local frequency expansion sequence (PN sign indicating number) and received signal synchronously, also must find enough strong and abundant multipath signal, and need estimate each strong channel fading factor (being channel estimating) directly, just can carry out to a plurality of contain identical information and fading characteristic mutually independently each single drive signal carry out phasing and high specific and merge and handle, thereby reach the purpose that improves signal-to-jamming ratio.
Pilot signal in the cdma system is used for transmitting known signal, utilize it not only can extract signal carrier and system regularly, can also carry out channel parameter estimation etc., the purpose of channel parameter estimation is to estimate channel fading factor c according to received signal and the pilot frequency sequence that knows nSuppose that mobile channel is the frequency selectivity slow fading channel, then can think c in a channel estimating interval nBe approximately constant.The formula of estimating is as follows: c ^ n = 1 NE C ∫ 0 NT C γ ( t - n T c ) · s 0 * ( t ) dt = c n + N a + N c + N z In (formula 1) formula, γ (t) is equivalent baseband receiving signals, s 0(t) be the pilot signal that knows, N a, N c, N zBe respectively that the not ideal enough multipath that causes of the correlation properties of spreading code disturbs, the output that multiple access disturbs and white noise produces after by correlator: T cBe the time width of a chip, NT cIt is the channel estimating interval; E cIt is the energy of a chip.
The implementation method of traditional RAKE receiver is finished by following steps: at first in whole multipath signal range of energy distribution to strong path search, more every strong footpath signal is followed the tracks of, carry out spread spectrum on this basis and receive with multipath and merge.Though the amount of calculation of this method is less, because each footpath arriving signal all has in a big way change at random under the actual mobile environment on amplitude and phase place, thereby causes frequent footpath to be switched, thereby influence the performance of RAKE receiver largely.
At said circumstances, (patent No. is that 00128222.0 proposition multipath signal Energy distribution window (abbreviating multipath energy window as) is defined as signal fadeout factor c to patent of invention nEffective distribution.This window width is determined by the time delay spreading range of multipath channel.Under different multipath fading environments (city, rural area, mountain area), width is respectively 3 microseconds, 6 microseconds, 15 microseconds.Because the uncertainty that multipath signal occurs.The width of multipath energy window should be got maximum possible value (being generally 30 microseconds), should add also in main window both sides that promptly width is two protection windows of △ chip, could guarantee can not lose multipath signal.Usually, main window width is about 15 microseconds, and the protection window width is about 7 microseconds.This main window fast channel estimation window of expressing one's gratification again.
Estimate that required amount of calculation is bigger owing in whole multipath energy window scope, carry out Fast Channel, the present invention is on the basis of above-mentioned Fast Channel estimating window and protection window notion, multipath energy window is divided into Fast estimation window and forward and backward protection window, as shown in Figure 1, its major parameter is as follows, forward and backward protection window: width is respectively 7 microseconds, is made as △ chip; The Fast estimation window: width is 15 microseconds, is made as L chip.In the Fast estimation window, carry out Fast Channel and estimate, in the protection window, carry out slow path search simultaneously.Slow path search that the present invention sets up and Fast Channel estimate that the multipath signal processing method that combines has not only solved multipath signal and uncertain problem occurred, make to handle and have robustness, also overcome simultaneously exercise question for channel estimator operand in the patent application of " based on the pilot channel tracking of multipath channel energy window gravity center track loop " big and conventional method switch the shortcoming of decreased performance when frequent in the footpath, so the inventive method is called " based on the multipath signal processing method of slow path search and Fast Channel estimation ".
The energy delay of multipath channel distributes and has following rule under mobile communication environment: the appearance in strong footpath is in groups, generally comprises more than two groups.The present invention is directed to this rule and introduced the notion of the sub-window of Fast estimation again; the Fast Channel estimating window is divided into a plurality of sub-windows, between the interval be called the protection window, like this multipath energy window comprised a plurality of Fast Channel estimator windows and the protection window; as shown in Figure 2, major parameter is described below.The number of the sub-window of Fast estimation mostly is M most, and each window width is an I chip, and I is chosen as 2,4,8 or bigger.Still adopt slow path search and Fast Channel to estimate the multipath signal processing method that combines to the processing of this a little window and protection window.The advantage of method that such processing has not only kept above-mentioned " Fast estimation window+front and back protection window ", and further reduced operand.So the present invention definitely is called " based on the multipath signal processing method of slow path search and multi-window fast channel estimation ".
Summary of the invention
An object of the present invention is to provide the multipath signal processing method that a kind of slow path search and multi-window fast channel are estimated, this method has significantly reduced amount of calculation when handling whole multipath energy window.
Another object of the present invention provides the multipath signal processing unit of a kind of slow path search and multi-window fast channel estimation, and this device has significantly reduced amount of calculation when handling whole multipath energy window.
According to an aspect of the present invention, the multipath signal processing method that a kind of slow path search and multi-window fast channel are estimated comprises step: multipath energy window is divided into Fast estimation window and protection window; Carrying out Fast Channel in the Fast estimation window estimates; In the Fast estimation window, carry out in the protection window, carrying out new at a slow speed path search when Fast Channel is estimated.
In addition, this method comprises: carry out initial slow path search in whole multipath energy window scope; Carry out the sampling of 1/2 chip-spaced to received signal; Press: c ^ n = 1 NE C ∫ 0 NT C γ ( t - n T c ) · s 0 * ( t ) dt = c n + N a + N c + N z Carry out relevant treatment, obtain required multipath channel and estimate, and its range value is adjudicated; Obtain initial effective value by slow path search; Adopt high multi-path resolved rate to estimate these initial effective diameter positions are aimed at the center of M the sub-window of Fast estimation respectively; In the multipath energy window scope, new at a slow speed path search is directly carried out in the new arrival beyond the described Fast estimation window in the protection window.
According to another aspect of the present invention, the multipath signal processing unit that a kind of slow path search and multi-window fast channel are estimated comprises: tapped delay line is used for baseband receiving signals is postponed storage; The slow path search device is used for obtaining to be spaced apart from the baseband sampling signal that tapped delay line receives the signal of 1/2 chip; The Fast Channel estimator is used in multipath energy window the multipath channel in the sub-window of a plurality of Fast estimation being estimated; Multipath energy window center of gravity calculation/loop filter is used for the channel estimation value from the output of Fast Channel estimator is carried out multipath energy window center of gravity calculation and loop filtering processing; Local PN code phase adjustment amount generator is used for described multipath energy window center of gravity calculation/loop filter result is adjudicated, and obtains PN code phase adjustment amount, and it is sent to the PN code generator; Strong footpath selector is used for the channel estimation value intensity from the output of Fast Channel estimator is compared, and therefrom selects J most powerful path, gives Rake correlator and Rake combiner respectively with its position and corresponding channel estimation value thereof; With the PN code generator, be used to be subjected to the control of multipath energy window center of gravity calculation/loop filter and local PN code phase adjustment amount generator and slow path search device, be used to finely tune the PN code phase, make main window gravity center adjust to desired value.
Beneficial effect of the present invention: the cdma system multipath channel estimator performance that the present invention constitutes is superior, can reduce the calculation of complex difficulty.
Description of drawings
Fig. 1 is the schematic diagram of multipath energy window division methods;
Fig. 2 is the schematic diagram that the method according to this invention is divided multipath energy window;
Fig. 3 is the block diagram according to the multipath signal processing unit of the slow path search of the embodiment of the invention and multi-window fast channel estimation.
Embodiment
The inventive method flow process is as follows:
At first, carry out initial slow path search: initial slow path search carries out in whole multipath energy window scope.After 1/2 chip-spaced sampling to received signal, press: c ^ n = 1 NE C ∫ 0 NT C γ ( t - n T c ) · s 0 * ( t ) dt = c n + N a + N c + N z Carry out relevant treatment, obtain required multipath channel and estimate, and its range value is adjudicated.By slow path search, can obtain initial effective diameter.These initial effective diameters must satisfy following condition: at first, the signal strength signal intensity of this initial effective diameter is greater than a certain decision threshold (this decision threshold should greater than the side lobe levels of PN sign indicating number part correlation); Secondly, the interval of per two initial effective diameters should be greater than the occupied width of Fast estimation window.If the initial effective diameter number that searches out is M, can determine M the sub-window of Fast estimation thus.
After this, carrying out multi-window fast channel estimates: adopt the estimation of high multi-path resolved rate, these initial effective diameter positions are aimed at the center of M the sub-window of Fast estimation respectively.In each Fast estimation (son) window, adopt single Fast Channel estimator to calculate the channel estimation value in every footpath in time-multiplexed mode; Perhaps to all Fast estimation (son) window, multiplexing same Fast Channel estimator, the Fast Channel estimator carries out Fast Channel to the multipath channel in this a little window and estimates, can in time follow the tracks of the multipath signal of frequent variations in the window, its renewal rate is about each second 9000 times, can adapt to the channel estimating under the mobile environment that the equivalent speed of a motor vehicle is 500km/h.
When carrying out the multi-window fast channel estimation, in the protection window, carry out new at a slow speed path search, also be to carry out new arrival search directly in the multipath energy window scope of slow path search device beyond removing these Fast estimation windows.In case detect new effective arrival footpath, then remove the sub-window of the most weak Fast estimation of signal, force to adjust the most weak sub-window of Fast estimation of intensity, and should new footpath with the sub-window covering of new Fast estimation.
The multipath signal processing unit structure that slow path search of the present invention and multi-window fast channel are estimated as shown in Figure 3, this device partly is made up of slow path search device, tapped delay line, multi-window fast channel estimator, multipath energy window center of gravity calculation/loop filtering/local PN code phase adjuster, strong footpath selector and PN code generator etc.The concrete function of each several part is described as follows.
The slow path search device: this part obtains to be spaced apart the signal of 1/2 chip from the baseband sampling signal that tapped delay line receives.(except the Fast estimation window that has distributed) carries out slow path search in the multipath energy window scope, obtaining initial effective diameter or newly to arrive the position of effective diameter, slow path search at first to Different Diameter carry out channel estimating (referring to c ^ n = 1 NE C ∫ 0 NT C γ ( t - n T c ) · s 0 * ( t ) dt = c n + N a + N c + N z , Specifically can adopt quick PN code generator and time-multiplexed correlator bank to realize.Intensity and threshold value with each footpath compares then, thereby whether decision is effectively to arrive the footpath signal.Declaring fast thresholding should be greater than the side lobe levels of PN sign indicating number part correlation, and at initial phase, M most powerful path is as initial effective diameter before choosing from these arrival footpath signals, and the interval of each initial effective diameter should be greater than the width of estimating window.After initialization was finished, each effectively arrived the footpath and is considered as new effective arrival footpath, if new effective intensity that arrives the footpath is then carried out the sub-window hand-off process of Fast estimation greater than the multipath intensity in the sub-window of some Fast estimation.
Tapped delay line: this part postpones storage to baseband receiving signals, and delay interval is the 1/K chip, and K gets 2 power.The length cover width of delay line is the multipath energy window of (L+2 △) chip-spaced.Delay line is drawn a tap every 1/2 chip, and the slow path search device is sent in K (L+2 △)/2 taps altogether.
Fast Channel estimator: in whole multipath energy window, comprise M Fast Channel estimating window at most.If the width of each Fast estimation window is the I chip, then need M * I * K delay line tap altogether.For reaching the purpose of saving hardware resource, can adopt time-multiplexed mode that the multipath channel in the sub-window of a plurality of Fast estimation is estimated.Also can adopt a plurality of channel estimators that a plurality of sub-windows are estimated simultaneously, to obtain the refresh rate of channel estimation value faster.The formula of channel estimating c ^ n = 1 NE C ∫ 0 NT C γ ( t - n T c ) · s 0 * ( t ) dt = c n + N a + N c + N z . The adjustment of the sub-window position of Fast estimation is decided jointly by the new position that effectively arrives the footpath that multipath energy window gravity center and slow path search device are obtained.When the sub-window of Fast estimation is not jumped out in the footpath variation, adopt patent " based on the pilot signal tracking of multipath channel center of gravity track loop " (patent No. is 00128222.0) that the position of multipath energy window is adjusted; In the time of in the position of new effective diameter is in the protection window, then need remove the sub-window of the most weak Fast estimation of intensity, increase a sub-window of new Fast estimation, making it to cover should be directly new, still adopted multipath energy window gravity center method that position of window is carried out meticulous adjustment afterwards.
Multipath energy window center of gravity calculation/loop filtering/local PN code phase adjustment amount generator: this part at first the channel estimation value from the output of Fast Channel estimator is carried out the multipath energy window center of gravity calculation and loop filtering is handled, again result is adjudicated, obtain PN code phase adjustment amount, and it is sent to the PN code generator.
Strong footpath selector: this part compares the channel estimation value intensity from the output of Fast Channel estimator, therefrom selects J most powerful path, gives Rake correlator and Rake combiner respectively with its position and corresponding channel estimation value thereof.
The PN code generator: this part is subjected to the control of multipath energy window center of gravity calculation/loop filtering/local PN code phase adjustment amount generator and slow path search device, multipath energy window center of gravity calculation/loop filtering/local PN code phase adjuster is used to finely tune the PN code phase, makes main window gravity center adjust to desired value.
Advantage of the present invention is mainly reflected in the following aspects:
1. slow path search is finished low multi-path resolved rate estimation, and Fast Channel estimates to adopt high multi-path resolved rate to estimate.
2. adopt slow path search and Fast Channel to estimate the method for combination, when handling whole multipath energy window, significantly reduced amount of calculation.
3. introduce the notion of Fast estimation window and protection window, solved the problem that the RAKE receptivity descended when the footpath is frequent in the conventional method switched.
4. on the basis of Fast estimation window, introduce the notion of the sub-window of Fast estimation, further reduced amount of calculation.
Be example with 3GPP WCDMA system below, the minimizing of the present invention aspect the channel estimation calculation amount is described.
Because of the spreading rate of WCDMA system is 3.84Mbps, if the multipath energy window width setup is 30 μ s, then length of window is about 116 chips, is 2 for the desirable Fast Channel estimator of the present invention window number, and its window width is 2 μ s (about 8 chips).
If the renewal rate that Fast Channel is estimated is per second 19200 times, multi-path resolved rate is 0.25 chip.The renewal rate that slow channel is estimated is per second 1000 times, and multi-path resolved rate is 0.5 chip.The footpath numerical table that computation complexity need be estimated with per second shows.
The inventive method requires to carry out Fast Channel in two sub-windows of Fast estimation estimates, carries out slow channel and estimate that computation complexity is in the protection window:
(8+8)/and 0.25 * 19.2k+ (116-8-8)/visible the present invention of 0.5 * 1k=1428800 can reduce computation complexity largely, and the required cost of paying is the difficulty that has increased the control aspect of how sub-window to a certain extent.
So far in conjunction with the preferred embodiments of the present invention the present invention is had been described in detail, those skilled in the art can make various improvement and variation under the situation of the scope and spirit essence that does not break away from claims.

Claims (9)

1. the multipath signal processing method estimated of slow path search and multi-window fast channel comprises step: multipath energy window is divided into Fast estimation window and protection window;
Carrying out Fast Channel in the Fast estimation window estimates;
In the Fast estimation window, carry out in the protection window, carrying out new at a slow speed path search when Fast Channel is estimated.
2. the multipath signal processing method that slow path search according to claim 1 and multi-window fast channel are estimated, wherein divide multipath energy window comprise divide the Fast estimation window and before described Fast estimation window and after the protection window.
3. the multipath signal processing method that slow path search according to claim 1 and multi-window fast channel are estimated wherein further comprises the Fast estimation window is divided into a plurality of sub-windows, and the interval between the described Fast estimation window constitutes the protection window.
4. according to the multipath signal processing method of any one described slow path search in the claim 1 to 3 and multi-window fast channel estimation, further comprise step:
In whole multipath energy window scope, carry out initial slow path search;
Carry out the sampling of 1/2 chip-spaced to received signal;
Press: c ^ n = 1 NE C ∫ 0 NT C γ ( t - n T c ) · s 0 * ( t ) dt = c n + N a + N c + N z Carry out relevant treatment, obtain required multipath channel and estimate, and its range value is adjudicated;
Obtain initial effective value by slow path search;
Adopt high multi-path resolved rate to estimate these initial effective diameter positions are aimed at the center of M the sub-window of Fast estimation respectively;
In the multipath energy window scope, new at a slow speed path search is directly carried out in the new arrival beyond the described Fast estimation window in the protection window.
5. the multipath signal processing method that slow path search according to claim 4 and multi-window fast channel are estimated; wherein further comprise when new effective arrival footpath in the protection window, occurring, force to adjust the step that the most weak sub-window of Fast estimation of intensity covers this strong footpath.
6. the multipath signal processing method that slow path search according to claim 4 and multi-window fast channel are estimated wherein carries out Fast Channel at the sub-window of Fast estimation and estimates, thereby can follow the tracks of the multipath signal of frequent variations in the window in time.
7. the multipath signal processing method that slow path search according to claim 4 and multi-window fast channel are estimated, wherein adopt single Fast Channel estimator to calculate the channel estimation value in every footpath in the sub-window of each Fast estimation, perhaps to the multiplexing same Fast Channel estimator of the sub-window of all Fast estimation in time-multiplexed mode.
8. the multipath signal processing unit estimated of slow path search and multi-window fast channel comprises:
Tapped delay line is used for baseband receiving signals is postponed storage;
The slow path search device is used for obtaining to be spaced apart from the baseband sampling signal that tapped delay line receives the signal of 1/2 chip;
The Fast Channel estimator is used in multipath energy window the multipath channel in the sub-window of a plurality of Fast estimation being estimated;
Multipath energy window center of gravity calculation/loop filter is used for the channel estimation value from the output of Fast Channel estimator is carried out multipath energy window center of gravity calculation and loop filtering processing;
Local PN code phase adjustment amount generator is used for described multipath energy window center of gravity calculation/loop filter result is adjudicated, and obtains PN code phase adjustment amount, and it is sent to the PN code generator;
Strong footpath selector is used for the channel estimation value intensity from the output of Fast Channel estimator is compared, and therefrom selects J most powerful path, gives Rake (Rake) correlator and Rake combiner respectively with its position and corresponding channel estimation value thereof; With
The PN code generator is used to be subjected to the control of multipath energy window center of gravity calculation/loop filter and local PN code phase adjustment amount generator and slow path search device, is used to finely tune the PN code phase, makes main window gravity center adjust to desired value.
9. the multipath signal processing unit that slow path search according to claim 8 and multi-window fast channel are estimated, wherein the Fast Channel estimator adopts time-multiplexed mode that the multipath channel in the sub-window of a plurality of Fast estimation is estimated, or adopt a plurality of channel estimators that a plurality of sub-windows are estimated simultaneously, to obtain the refresh rate of channel estimation value faster.
CNB011367253A 2001-10-22 2001-10-22 Multipath signal processing method with slow path search and multi-window fast channel estimation Expired - Fee Related CN1141816C (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CNB011367253A CN1141816C (en) 2001-10-22 2001-10-22 Multipath signal processing method with slow path search and multi-window fast channel estimation
PCT/CN2002/000740 WO2003036839A1 (en) 2001-10-22 2002-10-22 Multi-path signal process method and device using slow path searching and multi-window fast channel estimating

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNB011367253A CN1141816C (en) 2001-10-22 2001-10-22 Multipath signal processing method with slow path search and multi-window fast channel estimation

Publications (2)

Publication Number Publication Date
CN1347223A CN1347223A (en) 2002-05-01
CN1141816C true CN1141816C (en) 2004-03-10

Family

ID=4673864

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB011367253A Expired - Fee Related CN1141816C (en) 2001-10-22 2001-10-22 Multipath signal processing method with slow path search and multi-window fast channel estimation

Country Status (2)

Country Link
CN (1) CN1141816C (en)
WO (1) WO2003036839A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100388861C (en) * 2004-10-22 2008-05-14 华为技术有限公司 Signal processing method in mobile terminal random access process

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100341378C (en) * 2004-08-20 2007-10-03 华为技术有限公司 Method for searching upline special physical channel
CN101146222B (en) * 2006-09-15 2012-05-23 中国航空无线电电子研究所 Motion estimation core of video system
CN103428119B (en) * 2012-05-24 2018-02-02 中兴通讯股份有限公司 It is a kind of to eliminate method and the base station that channel estimation singular value influences
CN107196744B (en) * 2017-07-17 2020-05-05 中国科学院上海高等研究院 Method/system for detecting implicit communication signal, storage medium and electronic device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6163563A (en) * 1996-12-31 2000-12-19 Lucent Technologies Inc. Digital communication system for high-speed complex correlation
FR2805689B1 (en) * 2000-02-29 2003-07-04 Thomson Csf METHOD AND DEVICE FOR ESTIMATING A SPREAD CHANNEL
CN1151622C (en) * 2000-12-18 2004-05-26 信息产业部电信传输研究所 Pilot channel tracking method based on multipath channel energy window gravity center tracking loop

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100388861C (en) * 2004-10-22 2008-05-14 华为技术有限公司 Signal processing method in mobile terminal random access process

Also Published As

Publication number Publication date
CN1347223A (en) 2002-05-01
WO2003036839A1 (en) 2003-05-01

Similar Documents

Publication Publication Date Title
CN1174574C (en) CDMA receiving method and circuit
EP1095467B1 (en) Adaptive path selection threshold setting for ds-cdma receivers
KR100390562B1 (en) A spread spectrum demodulator for use in a multiple access communication system, a demodulation method, and an integrated circuit for demodulating a plurality of instances of spread spectrum signals
CN1135725C (en) Search window delay tracking in code division multiple access communication systems
AU756608B2 (en) Multipath propagation delay determining means using periodically inserted pilot symbols
JP4253680B2 (en) Wireless transceiver unit and method for processing received signals for wireless communication
CN100379166C (en) RAKE Receiver in CDMA system, with space-time transmitting diversity
US7349461B2 (en) Efficient back-end channel matched filter (CMF)
KR0173414B1 (en) Method and apparatus for identifying a coded communication signal
EP1774670B1 (en) Use of adaptive filters in cdma wireless systems employing pilot signals
CN1256564A (en) Communication terminal device and wireless communication method
KR100547737B1 (en) Rake receiver and method in direct sequence code division multiple access mobile communication system
CN1110162C (en) Precise PN code synchronizing method and device for wide-band CDMA system
CN1141816C (en) Multipath signal processing method with slow path search and multi-window fast channel estimation
CA2273659A1 (en) Channel estimation apparatus and communication terminal apparatus
CN1146135C (en) Method and apparatus for configuring Rake receiver
WO2004059865A1 (en) Training sequence detection scheme and device of downlink in tdd/cdma system
CN1486106A (en) Apparatus and method for selfadaptive beam forming of intelligent antenna
CN1112774C (en) Channel estimating method used in WCDMA receiver
CN1269325C (en) Channel estimation method for WCDMA communication system
CN1481094A (en) Adaptive beamforming method in wideband code division multiple access system
CN1180542C (en) Ruike receiver multipath searching device using energy estimation and multipath searching method
CN1131614C (en) Ruike and equalization cascade receiving method under the code division multiple address low band-spreading ratio and its equipment
CN101183881A (en) Multipath search method and apparatus, signal reception processing method and Rake receiver
CN100438385C (en) Baseband receiving synchronous acquiring method and apparatus for CDMA system

Legal Events

Date Code Title Description
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C06 Publication
PB01 Publication
C14 Grant of patent or utility model
GR01 Patent grant
C19 Lapse of patent right due to non-payment of the annual fee
CF01 Termination of patent right due to non-payment of annual fee