CN1402922A - Channel estimating method and apparatus thereof - Google Patents

Channel estimating method and apparatus thereof Download PDF

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Publication number
CN1402922A
CN1402922A CN00813629.7A CN00813629A CN1402922A CN 1402922 A CN1402922 A CN 1402922A CN 00813629 A CN00813629 A CN 00813629A CN 1402922 A CN1402922 A CN 1402922A
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power control
channel
amplitude
pilot sign
frequency pilot
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CN1188957C (en
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张宇
李道本
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Linkair Communications Inc
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Linkair Communications Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04—TPC
    • H04W52/30—TPC using constraints in the total amount of available transmission power
    • H04W52/32—TPC of broadcast or control channels
    • 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
    • H04L25/023—Channel estimation using sounding signals with direct estimation from sounding signals with extension to other symbols
    • H04L25/0232—Channel estimation using sounding signals with direct estimation from sounding signals with extension to other symbols by interpolation between sounding signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2201/00—Indexing scheme relating to details of transmission systems not covered by a single group of H04B3/00 - H04B13/00
    • H04B2201/69—Orthogonal indexing scheme relating to spread spectrum techniques in general
    • H04B2201/707—Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation
    • H04B2201/70701—Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation featuring pilot assisted reception

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

Abstract

The present invention discloses a method and apparatus of time division pilot channel estimation using in the spread spectrum communication technology, which obtain the phase and amplitude estimation value of the channel using the adjacent pilot signals, and correct the amplitude of one of the pilot symbol utilizing the power control instructino know to the receiver corresponding to the pilot signal, and acquire channel estimation result among the traffic signal by interposing values. The present invention can be suitable to various modulating manner, especially multi-level modulating manner in the CDMA system with power control, so as to significantly improve the performance of the mobile communication system.

Description

Channel estimation methods and device
Channel estimation methods and engineering device technique field
It is applied to the channel estimation methods of various modulation systems the present invention relates to radio spread spectrum communication and digital mobile communication field, under more particularly to a kind of high data rate transfer and realizes the device of this method.Background of invention
In Modern High-Speed mobile communication, for the requirement to high data rate so that one of core content being increasingly becoming to the research of Multilevel modulation system in radio communication.But multipath and larger Doppler frequency-shift are always the main bottleneck that many level of limitation, the modulation system of leggy are applied under high-speed mobile environment.To overcome these influences of fading channel, it is necessary to carry out effective channel estimation.Particularly in 3G (Third Generation) Moblie, it is desirable to which mobile station adapts to high data rate requirement, and to stand the deep fade environment of about 500Hz Doppler frequency-shifts, in this regard, there is several solution in the prior art.
For example, Nokia, the Errisson in Europe are in WCDMA（WCDMA the scheme proposed in) is the Combined estimator using CP continuous pilot channel and dedicated pilot (channel) in its forward channel, and the estimation of dedicated pilot (channel) is then used in backward channel（It see 3GPPTS25.211).Dedicated pilot (channel) method of estimation is in each channel of transmitting terminal, every certain one frequency pilot sign of interval transmission, the parameter of the channel estimated using frequency pilot sign carries out channel compensation to the data symbol after this frequency pilot sign, to eliminate influence of the channel to transmission signal.In this special pilot channel structure, because pilot signal and service signal use time-multiplexed mode, the channel estimation of service signal is to carry out interpolation calculation by the estimated characteristic of channel of the frequency pilot sign before and after it to obtain.Therefore, this method is feasible, such as the QPSK employed in WCDMA only for the modulation system of single level, because in single level modulation Under mode, channel estimation only needs to estimate the phase characteristic change of channel, and the change to amplitude need not be estimated, i.e., under single level modulation mode, it is not necessary to which consideration is because of the influence caused by Power Control to the estimation of channel magnitude.But, for Multilevel modulation mode, such as 16QAM, 64QAM etc., due to the Power Control certainly existed in CDMA systems, the amplitude for causing adjacent pilot symbols is not only influenceed by the amplitude fading of channel, and the influence being power controlled, the amplitude size of adjacent pilot symbols not only reflects the change of channel magnitude in time period, while also contains the change of the transmission power caused by Power Control.So, there is larger error in the estimate using the channel magnitude obtained by this dedicated pilot (channel) method of estimation, the correctness of channel estimation can not accurately and efficiently be ensured, and then it cannot be guaranteed that the modulation system of more higher-dimension is applied under high-speed mobile environment.The content of the invention
Provided by the present invention for high data rate transfer and the channel estimation methods and device of high-speed mobile environment, it is subject to by way of the time-division dedicated pilot (channel) estimation to being generally used in the prior artWen Jin, can be significantly reduced the evaluated error to channel magnitude brought by power control techniques, can adapt to various modulation systems, especially Multilevel modulation mode in it there is the CDMA systems of Power Control.
One kind that the present invention is provided is applied to CDMA（CDMA) the time multiplexed pilot channel estimation methods in system, it is when carrying out channel estimation using time multiplexed pilot method, after the amplitude estimation value of adjacent pilot symbols is obtained, first with known to receiver between the frequency pilot sign corresponding carried out power control command, the range value of amendment wherein some frequency pilot sign, to eliminate influence of the Power Control to signal amplitude, then obtain by interpolation the channel estimation results of service signal therebetween.
According to the invention described above method, further it can also comprise the steps of：
A) the docking collection of letters number carries out a despread-and-demodulation；
B) pilot signal and service signal are gone out to the despread obtained Signal separator that demodulates； C) enter the separation of line amplitude and phase to pilot signal, and obtain the amplitude of channel and the estimate of phase；
D) to the amplitude estimation value of obtained channel, between adjacent pilot symbols, using known to receiver between the frequency pilot sign corresponding carried out power control command, the range value of amendment wherein some frequency pilot sign, to eliminate influence of the Power Control to signal amplitude；
E) according to the phase estimation value of channel obtained above and revised amplitude estimation value, the channel estimation results of the service signal between frequency pilot sign are obtained by interpolation；
F) channel estimation results are utilized, phase compensation is carried out to service signal；
G) service signal after compensating phase compensation carries out Maximal ratio combiner, adjudicates and output data.
The range value of above-mentioned some frequency pilot sign of amendment can be：When power control command is increase transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 101, or ι Λ ο ^ are multiplied by the amplitude estimation value of latter frequency pilot sign;When power control command is reduces transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by Ι Λ Ο55, or ι ο are multiplied by the amplitude estimation value of latter frequency pilot sign;Wherein △ is power control step-size.
One kind that the present invention is provided is applied to CDMA（CDMA) the time multiplexed pilot channel estimator in system, at least includes：
Signal demodulation device, the docking collection of letters number carries out a despread-and-demodulation；
Shunt, isolates pilot signal and service signal；
Pilot channel estimator, carries out channel estimation using pilot signal, obtains the amplitude of channel and the estimate of phase；
Arithmetic unit 1, to the amplitude estimation value of obtained channel, between adjacent pilot symbols, using known to receiver between the frequency pilot sign corresponding carried out power control command, amendment wherein certain The range value of individual frequency pilot sign, to eliminate influence of the Power Control to signal amplitude；
Arithmetic unit 2, according to the phase estimation value of channel obtained above and revised amplitude estimation value, the channel estimation results of the service signal between frequency pilot sign are obtained by interpolation；
Phase compensator, using above-mentioned channel estimation results, phase compensation is carried out to service signal；Merge and decision device, the service signal after phase compensation is merged, adjudicate and output data.
According to the channel estimator of above-mentioned technical proposal, wherein described arithmetic unit 1 can be a multiplier, it inputs the power control command that power control command generator is exported in the respectively amplitude estimation value and receiver of the channel of Pilot channel estimator output；And
When the power control command between adjacent pilot symbols is increase transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 1, or is multiplied by 1/10 ∞ to the amplitude estimation value of latter frequency pilot sign；When the power control command between adjacent pilot symbols is reduces transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by l/io, or the amplitude estimation value of latter frequency pilot sign is multiplied by
10Γο;Wherein △ is power control step-size.
Delayer can be further comprised according to the channel estimator of above-mentioned technical proposal, phase compensator is sent into after the channel estimation results of service signal are delayed through delayer between the corresponding frequency pilot sign obtained by the described interpolation of arithmetic unit 2 phase compensation is carried out to service signal.
According to the channel estimator of above-mentioned technical proposal, wherein described merging and decision device can be Maximal ratio combiner and decision device, Maximal ratio combiner is carried out to the service signal after phase compensation, adjudicated and output data.
Using a kind of CDMA of the present invention（CDMA) the receiving system in system, including reception antenna, intermediate frequency radio demodulating part, despreading section, channel estimation and judgement part, decoding and information source recovered part, wherein： Described channel estimation and judgement part are using time multiplexed pilot channel estimator of the invention, including shunt, Pilot channel estimator, arithmetic unit 1, arithmetic unit 2 and phase compensation and merging and judgment device, the signal of wherein despread demodulation goes out pilot signal and service signal through demultiplexer separates, the phase and amplitude of channel is estimated through Pilot channel estimator, it is modified through 1 pair of amplitude estimated of arithmetic unit, to eliminate influence of the Power Control to signal amplitude, the channel estimation results of the service signal between corresponding frequency pilot sign are obtained by interpolation through arithmetic unit 2, channel estimation results are exported to phase compensation device, phase compensation is carried out to service signal, and the service signal after phase compensation is merged in merging and judgment device, adjudicate and output data.
According to the receiving system of above-mentioned technical proposal, wherein described arithmetic unit 1 can be a multiplier, and it inputs the power control command that power control command generator is exported in the respectively amplitude estimation value and receiver of the channel of Pilot channel estimator output；And
When the power control command between adjacent pilot symbols is increase transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by1ο, or ι/ο is multiplied by the amplitude estimation value of latter frequency pilot sign¾;When the power control command between adjacent pilot symbols is reduces transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by ι/ο, or the amplitude estimation value of latter frequency pilot sign is multiplied by
10^ ;Wherein Δ is power control step-size.
According to the receiving system of above-mentioned technical proposal, wherein described merging and decision device can be Maximal ratio combiner and decision device, Maximal ratio combiner is carried out to the service signal after phase compensation, adjudicated and output data.
Receiving Xi System according to the signal of above-mentioned technical proposal further may include delayer, and phase compensator is sent into after the channel estimation results of service signal are delayed through delayer between the corresponding frequency pilot sign obtained by the described interpolation of arithmetic unit 2 and carries out phase compensation to service signal.
Here, described power control step-size can be sent to by way of signaling in real time by emitter Receiver or by default, and carry out in the form of broadcast announcing, etc..
Disclosed herein channel estimation technique, system utilizes the power control bit formed in receiver, and certain power control step-size, the evaluated error caused by the use of power control techniques for channel magnitude in existing channel estimation technique is eliminated, so as to realize the channel estimation under Multilevel modulation mode.
Disclosed herein channel estimation technique compared with the dedicated pilot (channel) estimation technique of prior art, overcome the defect that time-division dedicated pilot (channel) estimation of the prior art is not applied for multidimensional simplex mode, all advantages of time-division dedicated pilot (channel) estimation of the prior art are not only remained, and can be allowed to be applied under various modulation systems.And there is Power Control
In cdma system, using disclosed herein channel estimation technique, in theory analysis and Computer Simulation all it was demonstrated that this method can bring significantly improving for performance of mobile communication system.Brief Description Of Drawings
Fig. 1 is the simple schematic block diagram of a CDMA mobile communication system.
Fig. 2 is according to a preferred embodiment of the present invention block diagram.
Fig. 3 is the simulation curve performance comparision of the present invention and prior art under 16QAM modulation systems.Implement the mode of the present invention
The present invention will be described in detail below in conjunction with the accompanying drawings.Refer to the attached drawing 1, Fig. 1 shows a simple CDMA mobile communication system.Information source generator 101 produces signal, and encoded device 102 is encoded, after frequency multiplier 103 is spread, and spread-spectrum signal is sent to modulator 104 and carries out intermediate frequency, radio-frequency modulations, then emitted antenna 105 launches signal power.In receiver one end, the received signal power of reception antenna 106, then demodulated device 107 are demodulated into baseband signal, and despreader 108 completes despreading processing, and channel estimation circuit 109 completes to translate Channel estimation needed for code and information source restoring circuit 110, and according to the difference of received signal and interference level, power control command is produced, being transferred to transmitting terminal through power control loop 111 carries out Power Control.
In existing cdma system, power control techniques are generally used, and it is generally divided into open Loop Power control, close-loop power control and open sea wharf.The wherein frequency highest of close-loop power control, its purpose is to partly track rapid fading.Close-loop power control requirement is once adjusted within 0.5-lms time to transmission signal power.
Due to the presence of Power Control, new content is introduced to channel estimation, especially for the channel estimation under time-division dedicated pilot (channel) mode.Because in general, the interval of adjacent time multiplexed pilot signal and power control time section are about the same.So, different pilot signals is just in different power control times section.Therefore, the changes in amplitude of adjacent pilot signals not only reflects the channel magnitude characteristic variations in the period, while also reflecting in the period due to the change of transmission power caused by Power Control.Under single level modulation mode, because channel estimation only needs to estimate the phase characteristic change of channel, and the change of amplitude need not be estimated, therefore in the absence of the influence brought due to Power Control as described above when using time-division dedicated pilot mode, because Power Control does not change the phase characteristic of signal.But under Multilevel modulation mode, this problem is just highlighted.Because receiving the amplitude and phase of signal all comprising transmission signal message, therefore all must accurately and reliably obtain, this requires channel estimation must be while completing the amplitude and phase estimation to channel.
If there is no Power Control, then can be using the phase estimation identical method with channel, utilize adjacent pilot symbols estimated channel magnitude and phase characteristic, according to certain given algorithm, such as linear interpolation algorithm or Gauss interpolation algorithm enter row interpolation, obtain the channel magnitude and the estimate of phase of the service signal between the frequency pilot sign.
But it is almost non-existent in the absence of the cdma system of Power Control.Therefore in practice for Multilevel modulation mode, the above-mentioned method of estimation for channel magnitude there is in theory error and Defect.Because as it was previously stated, the amplitude size of adjacent pilot symbols not only reflects the change of channel magnitude in time period, while also contains the change of the transmission power caused by Power Control.So if being not added with improving, then the estimate of resulting channel magnitude certainly exists error.If the step-length of Power Control, i.e. the change value of the transmission power of adjacent power control time section is than larger, such as it is IdB or 2dB, then by the evaluated error to channel magnitude that Power Control is brought also can be larger, so as to make time multiplexed pilot channel method performance drastically deteriorate or even can not use at all.
As described above, for close-loop power control, its control command is that the measurement of size is disturbed signal by receiver, so as to which power control command is fed back into emitter, if received signal quality is too low, emitter is required to increase the transmission power of a power control step-size, transmission power that is on the contrary then reducing a power control step-size.That is receiver is clearly known, and and do not need it is any type of signal receiving terminal, to it is any it is corresponding receive the power control actions taken of signal time section, be that increase transmission power still reduces transmission power.Therefore, when carrying out channel estimation using time multiplexed pilot method, after the range value of adjacent pilot symbols is obtained, the estimate of the channel magnitude of service signal therein is not obtained by interpolation immediately, because can introduce like that because Power Control causes transmission power to change caused error.The power control actions carried out between the correspondingly frequency pilot sign that we can have been known using receiver, the range value of amendment wherein some frequency pilot sign.Such as, if the Power Control carried out within the time period is increase transmission power, then the increase of this transmission power necessarily causes the increase of latter pilot symbol amplitudes value, the calculating of its value added is very simple, assuming that the step-length of Power Control is A dB, then the amplitude value added of corresponding frequency pilot sign is 1 (^ times.Here it is the error of the channel magnitude estimate caused due to the presence of Power Control.It can be seen that power control step-size Δ is bigger, this influence will be more obvious.Before interpolation calculation is carried out, by the amplitude estimation value of latter frequency pilot sign by a divider, divided by
10, or by the amplitude estimation value of previous frequency pilot sign by a multiplier, it is multiplied by 10 °.If the Power Control carried out in time period is to reduce transmission power, led according to same principle amendment The amplitude estimation value of frequency symbol, i.e., before interpolation calculation is carried out, by the amplitude estimation value of latter frequency pilot sign by a multiplier, be multiplied by 10., or the amplitude estimation value of previous frequency pilot sign passed through into a divider, divided by 10^.By the amendment of such cylinder list, Power Control is eliminated for the influence that Multilevel modulation time-division dedicated pilot (channel) is estimated, it is achieved thereby that correct channel estimation.
Refer to the attached drawing 2, accompanying drawing 2 shows that a kind of channel estimator of the invention realizes the estimation to fading channel characteristic by frequency pilot sign and interpolation algorithm.First, despread signal is obtained by demodulation device 112, then pilot signal and service signal after respectively obtaining despreading through shunt 113；Pilot signal is that, for doing channel estimation, therefore it obtains the amplitude and phase estimation value of channel by Pilot channel estimator 114, the influence of Power Control is wherein included in range value, it is therefore necessary to removed；The output power bit " 1 " of generator 115 of power control bit or " 0 ", on the one hand it will feed back to transmitting terminal and carry out actual power adjustment, on the other hand the multiplier to determine multiplier 116 is 10^ or wherein Δ is power control step-size, and its unit is dB.The influence that Power Control is brought is got rid of by the channel magnitude estimate after multiplier, so as to carry out the interpolated channel estimation of service signal by 117, the channel estimation value for obtaining service signal (contains amplitude and phase）, then there is provided the judgement that service signal is carried out to phase compensator 119 and Maximal ratio combiner and decision device 120 through delayer 118.
Above example obviously has assumed that power control step-size △ size is known to receiver, and otherwise receiver can not know exactly which the size that the channel magnitude estimate estimated to pilot signal should be corrected.There can be two methods to obtain the size of this step-length：1) receiver is sent to by way of signaling by emitter in real time；2) the relatively-stationary step sizes of default one, and being announced in the form of broadcast.
Refer to the attached drawing 3, be shown in accompanying drawing 3 under 16QAM modulation systems, the present invention and the simulation performance curve ratio of prior art compared with.Abscissa is Eb/No in figure, and unit is db, and ordinate is error sign ratio.In two ^ curves shown in figure, an imaginary curve is according to provided by the present invention The System performance profiles that channel estimation methods emulation is obtained, another solid-line curve is not use method provided by the present invention, and the simulation result being directly applied to without change applied to the channel estimation methods under single level modulation mode under 16QAM modulation systems., it is apparent that improved method of the present invention can bring significant performance improvement, about l-2dB from the simulation curve.Rough estimation shows, this increase equivalent to the capacity that 26%-58% is brought to cdma system.Because the method disclosed in the present does not bring more complexity to system, thus the gain brought using the method disclosed in the present be undoubtedly it is worth.
Inventive concept is applied in CDMA（CDMA) the receiving system in system, the receiving system includes reception antenna, intermediate frequency radio demodulating part, despreading section, channel estimation and judgement part, decoding and information source recovered part.Channel estimation and judgment unit therein are divided into the time multiplexed pilot channel estimator using the technology of the present invention, it utilizes the power control bit formed in receiver, and certain power control step-size, eliminate in channel estimation because of the evaluated error caused by Power Control for channel magnitude, so as to realize the channel estimation under Multilevel modulation mode.Method having thus described the invention, for one of ordinary skill in the art, there can also be more embodiment, although the present invention only gives the embodiment under 16QAM modulation systems, but for the modulation system of more higher-dimension, the those of ordinary skill of same domain can obviously implement the present invention, and obtain good channel estimation results.

Claims (16)

  1. Claims
    1st, it is a kind of to be applied to CDMA（CDMA) the time multiplexed pilot channel estimation methods in system, it is characterised in that：
    When carrying out channel estimation using time multiplexed pilot method, after the amplitude estimation value of adjacent pilot symbols is obtained, first with known to receiver between the frequency pilot sign corresponding carried out power control command, the 4 fathers just wherein range value of some frequency pilot sign, to eliminate influence of the Power Control to signal amplitude, then obtain by interpolation the channel estimation results of service signal therebetween.
    2nd, the channel estimation methods as described in claim 1, it is characterised in that the range value of described some frequency pilot sign of amendment includes：
    When power control command is increase transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 10^, or is multiplied by 1/10 to the amplitude estimation value of latter frequency pilot sign.；
    When power control command is reduces transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 1/10^, or the amplitude estimation value of latter frequency pilot sign is multiplied by
    Wherein Δ is power control step-size.
    3rd, channel estimation methods as claimed in claim 2, it is characterised in that described power control step-size is sent to receiver by way of signaling in real time by emitter.
    4th, channel estimation methods as claimed in claim 2, it is characterised in that described power control step-size is announced by default, and in the form of broadcast.
    5th, the channel estimation methods as described in claim 1, it is characterised in that this method is further comprised the steps of：
    The docking collection of letters number carries out a despread-and-demodulation；
    Pilot signal and service signal are gone out to the despread obtained Signal separator that demodulates；
    Enter the separation of line amplitude and phase to pilot signal, and obtain the amplitude of channel and estimating for phase Evaluation；
    To the amplitude estimation value of obtained channel, between adjacent pilot symbols, using known to receiver between the frequency pilot sign corresponding carried out power control command, the range value of amendment wherein some frequency pilot sign, to eliminate influence of the Power Control to signal amplitude；
    According to the phase estimation value of channel obtained above and revised amplitude estimation value, the channel estimation results of the service signal between frequency pilot sign are obtained by interpolation；
    Using the channel estimation results, phase compensation is carried out to service signal；
    Service signal after compensating phase compensation carries out Maximal ratio combiner, adjudicates and output data.
    6th, channel estimation methods as claimed in claim 5, it is characterised in that the range value of described some frequency pilot sign of amendment includes：
    When the power control command between adjacent pilot symbols is increase transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 10^, or is multiplied by 1/10^ to the amplitude estimation value of latter frequency pilot sign；When the power control command between adjacent pilot symbols is reduces transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 1/10., or the amplitude estimation value of latter frequency pilot sign is multiplied by
    10^°；Wherein △ is power control step-size.
    7th, it is a kind of to be applied to CDMA（CDMA) the time multiplexed pilot channel estimator in system, it is characterised in that at least include：
    Signal demodulation device, the docking collection of letters number carries out a despread-and-demodulation；
    Shunt, isolates pilot signal and service signal；
    Pilot channel estimator, carries out channel estimation using pilot signal, obtains the amplitude of channel and the estimate of phase；
    Arithmetic unit 1, to the amplitude estimation value of obtained channel, between adjacent pilot symbols, using known to receiver between the frequency pilot sign corresponding carried out power control command, the range value of amendment wherein some frequency pilot sign, to eliminate influence of the Power Control to signal amplitude； Arithmetic unit 2, according to the phase estimation value of channel obtained above and revised amplitude estimation value, the channel estimation results of the service signal between frequency pilot sign are obtained by interpolation；
    Phase compensator, using above-mentioned channel estimation results, phase compensation is carried out to service signal；Merge and decision device, the service signal after phase compensation is merged, adjudicate and output data.
    8th, channel estimator as claimed in claim 7, it is characterized in that described arithmetic unit 1 is a multiplier, it inputs the power control command that power control command generator is exported in the respectively amplitude estimation value and receiver of the channel of Pilot channel estimator output；And
    When the power control command between adjacent pilot symbols is increase transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 1, or is multiplied by 1/10^ to the amplitude estimation value of latter frequency pilot sign;When the power control command between adjacent pilot symbols is reduces transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 1/10^, or the amplitude estimation value of latter frequency pilot sign is multiplied by
    10^；Wherein △ is power control step-size.
    9th, channel estimator as claimed in claim 8, it is characterised in that described power control step-size is sent to receiver by way of signaling in real time by emitter.
    10th, channel estimator as claimed in claim 8, it is characterised in that described power control step-size is announced by default, and in the form of broadcast.
    11st, channel estimator as claimed in claim 7, it is characterized in that further comprising delayer, phase compensator is sent into after the channel estimation results of service signal are delayed through delayer between the corresponding frequency pilot sign obtained by the described interpolation of arithmetic unit 2 phase compensation is carried out to service signal.
    12nd, channel estimator as claimed in claim 7, it is characterised in that described merging and decision device are Maximal ratio combiner and decision device, and Maximal ratio combiner is carried out to the service signal after phase compensation, are adjudicated and output data.
    13rd, it is a kind of to be applied to CDMA（CDMA) the receiving system in system, bag Include reception antenna, intermediate frequency radio demodulating part, despreading section, channel estimation and judgement part, decoding and information source recovered part, it is characterised in that：
    Described channel estimation and judgment unit is divided into a time-division Pilot channel estimator, including shunt, Pilot channel estimator, arithmetic unit 1, arithmetic unit 2 and phase compensation and merging and judgment device, the signal of wherein despread demodulation goes out pilot signal and service signal through demultiplexer separates, the phase and amplitude of channel is estimated through Pilot channel estimator, it is modified through 1 pair of amplitude estimated of arithmetic unit, to eliminate influence of the Power Control to signal amplitude, the channel estimation results of the service signal between corresponding frequency pilot sign are obtained by interpolation through arithmetic unit 2, channel estimation results are exported to phase compensation device, phase compensation is carried out to service signal, and the service signal after phase compensation is merged in merging and judgment device, adjudicate and output data.
    14th, receiving system as claimed in claim 13, it is characterized in that described arithmetic unit 1 is a multiplier, it inputs the power control command that power control command generator is exported in the respectively amplitude estimation value and receiver of the channel of Pilot channel estimator output；And
    When the power control command between adjacent pilot symbols is increase transmission power, then 1 ο ° is multiplied by the amplitude estimation value of previous frequency pilot sign, or the amplitude estimation value of latter frequency pilot sign is multiplied by;When the power control command between adjacent pilot symbols is reduces transmission power, then the amplitude estimation value to previous frequency pilot sign is multiplied by 1/105, or the amplitude estimation value of latter frequency pilot sign is multiplied by
    10 wherein △ are power control step-size.
    15th, receiving system as claimed in claim 13, it is characterised in that described merging and decision device are Maximal ratio combiner and decision device, and Maximal ratio combiner is carried out to the service signal after phase compensation, are adjudicated and output data.
    16th, the letter of service signal between receiving system as claimed in claim 13, it is characterised in that further comprise delayer, the corresponding frequency pilot sign obtained by the described interpolation of arithmetic unit 2 Feeding phase compensator carries out phase compensation to service signal after road estimated result is delayed through delayer.
CN00813629.7A 2000-11-09 2000-11-09 Channel estimating method and apparatus thereof Expired - Fee Related CN1188957C (en)

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CN112737988B (en) * 2020-12-29 2023-12-05 芯翼信息科技(上海)有限公司 Channel estimation method, device, electronic equipment and storage medium
CN114095319B (en) * 2021-11-05 2023-08-18 成都中科微信息技术研究院有限公司 Time-frequency smoothing method for 5G channel estimation by adopting amplitude-phase separation technology

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CN101091363B (en) * 2004-10-29 2013-02-06 艾利森电话股份有限公司 Channel estimation

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