CN101243622B - Uplink signal transmitting method for user device and its method for timing synchronization - Google Patents
Uplink signal transmitting method for user device and its method for timing synchronization Download PDFInfo
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- CN101243622B CN101243622B CN2005800513656A CN200580051365A CN101243622B CN 101243622 B CN101243622 B CN 101243622B CN 2005800513656 A CN2005800513656 A CN 2005800513656A CN 200580051365 A CN200580051365 A CN 200580051365A CN 101243622 B CN101243622 B CN 101243622B
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- subscriber equipment
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- base station
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- upward signal
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
- H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
- H04B7/2662—Arrangements for Wireless System Synchronisation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/0005—Synchronisation arrangements synchronizing of arrival of multiple uplinks
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Abstract
An uplink signal transmission method for a user equipment and a timing synchronization method thereof include the steps of: estimating an downlink channel impulse response h by the user equipment; determining the conjugation of h; preparing a uplink signal to be transmitted; filtering said signal by using a coefficient matched with h the matched filter has a conjugation of h; determining whether the traffic channel of the user equipment adopts pre-rake technique, and deciding whether the transmission timing is adjusted according the determining result; transmitting the timing-adjusted or unadjusted uplink signal to a base station by the user equipment; making correlation or FFT transformation for uplink pilot by the base station finding peak position, and performing uplink synchronization. Present invention can make the base station receive a great amount of energies of a certain multipath tap, improve uplink synchronous detection performance, thereby improve uplink synchronization performance.
Description
Technical field
The present invention relates to the digital mobile communication field, particularly in time-division duplex (TD-SCDMA) communication system, the upward signal launching technique of subscriber equipment, and carry out regularly synchronous method.
Background technology
Because the characteristic of wireless channel, wireless signal need be passed through a plurality of reflected by objects and scattering around the transmitting terminal, have formed a plurality of signal branch, these signal branch will be expanded different delay, form different impulse responses, and the time delay of Here it is multipath is expanded.Transmit signal energy will be distributed to different time delays like this, reduce the energy of the impulse response on certain time delay, cause receiving terminal difficult to estimation regularly.And tdd communication systems has been owing to adopted identical carrier frequency in up-downgoing, so the channel of uplink and downlink signals process is identical, according to principle of reciprocity, the impulse response of up-downgoing is identical.Thereby can the impulse response through up channel estimate the impulse response of down channel, perhaps conversely, estimate the impulse response of up channel through the impulse response of down channel.
Pre-rake (in advance Rake) technology is the impulse response that down channel is estimated in a kind of impulse response that utilizes up channel, and through adjustment downlink signal so that simplify a kind of technology of descending reception.Concrete implementation procedure is described below.
The base station receives the signal of domestic consumer's emission, through the estimation to ascending pilot frequency, can obtain the characteristic of up channel.The tap that CDMA (code division multiple access) system uplink channel estimated result becomes during for some.The base station through joint-detection or Rake (rake) thus receiving the tap signal on the different delay collected to merge can obtain receiving better effect than single footpath.But the signal of common CDMA transmitter emission is diffused into different time delays because of energy after arriving receiver, and the energy in so effective tap is lower than transmit signal energy.Because the time-varying characteristics of Rayleigh channel, the energy in the tap is in continuous variation, and the less energy after the Rayleigh fading in the tap is declined probably, and is flooded by noise, causes the tap detection difficult.Pre-rake transmits through adjustment, makes through adjusted signal through can occur the peak value of original signal behind the channel at receiver end.A very big value will appear in certain tap of receiver estimation just; It is big that energy around this peakedness ratio on the time delay is wanted; And concentrated the energy of most primary signals; Thereby make receiver only to carry out channel estimating and demodulation, greatly reduce the complexity of receiver the peak value tap.Make receiver the filtering of method of adjustment for primary signal being carried out be complementary of peak value occur with channel impulse response.For example: when channel impulse response was h, the filter of coupling was the conjugation of h, and downstream signal is redispatched away through the filtering of this filter earlier before emission.Through the downstream signal of such special processing through behind the channel once more with the channel impulse response convolution, such effect just is equivalent to original signal and has realized that a rake receives, thereby this technology is called as the Pre-rake technology.
The principle of Pre-rake transmitter is as shown in Figure 1; From figure, can see; Downstream signal had carried out Filtering Processing before sending, the substitution signal of downlink is being concentrated on one or several chips through the Energy distribution after the channel, thereby reduced the complexity of subscriber equipment.For subscriber equipment, whether the base station has the normal receiving function that the Pre-rake function does not influence subscriber equipment, when the Pre-rake technology is adopted in the base station, can adopt simple user receiving equipment more.
On the other hand, to wireless communication system, TD-SCDMA (time-division duplex) communication system particularly.Because subscriber equipment is different with base station distance, need set up accurate up timing synchronously so that right demodulation information.Synchronous required precision is less than the magnitude of a chip.
By characteristic of channel decision, the time delay in the footpath that uplink synchronous is different keeps relative stability, but the amplitude of multipath is brought difficulty to uplink synchronous like this along with the time constantly sharply changes.Because uplink synchronous need be confirmed the timing of uplink synchronous according to the maximum path position of intensity, so that synchronous CDMA system can be according to the up emission of timing adjustment subscriber equipment of signal.Up timing is confirmed according to the tap of maximum in the base station; And the signal of common subscriber equipment emission is because the disperse and the decline of multipath energy; Instantaneous most powerful path in the single tap is not representative usually; And have to obtain " center of gravity " of a plurality of effective diameters, could represent the characteristic of whole channel, and then through synchronously the energy in the whole demodulation window being merged as far as possible.
Therefore, the existing upward signal launching technique of subscriber equipment for base station side, can not be easy to just realize that uplink synchronous detects.
Summary of the invention
Technical problem to be solved by this invention is to provide the launching technique of a kind of subscriber equipment to upward signal, improves the base station synchronization performance through subscriber equipment being adopted preparatory rake technique.
The present invention provides a kind of upward signal launching technique of subscriber equipment, is used for the time-division duplex communication system, and this method comprises the steps:
Subscriber equipment is estimated down channel impulse response h;
Subscriber equipment is confirmed the conjugation of h according to said down channel impulse response h;
The upward signal that the subscriber equipment preparation will be launched;
Subscriber equipment carries out the filtering that is complementary with channel impulse response h to the said upward signal that will launch, and the filter of coupling is the conjugation of h;
The upward signal that subscriber equipment will pass through behind the said filter filtering is emitted to the base station through up channel.
The present invention also provides a kind of upward signal to the subscriber equipment emission to carry out regularly synchronous method, is used for the time-division duplex communication system, and this method comprises the steps:
Subscriber equipment is estimated down channel impulse response h;
Subscriber equipment is confirmed the conjugation of h according to said down channel impulse response h;
The upward signal that the subscriber equipment preparation will be launched;
Subscriber equipment carries out the filtering that is complementary with channel impulse response h to the said upward signal that will launch, and the filter of coupling is the conjugation of h;
The upward signal that subscriber equipment will pass through behind the said filter filtering is emitted to the base station through up channel;
Being correlated with or Fourier transform to the pilot tone of said upward signal in the base station, finds out peak;
According to this peak, for synchronization code multi-address division system, base station physical access channel signal; Require subscriber equipment up emission regularly to be adjusted according to the adjustment amount of confirming; So that compensating for path postpones, for the Asynchronous Code Division Multiple Access system, the up reception of base station adjustment regularly.
Wherein, described upward signal can comprise uplink synchronizing signals and uplink service signal, and described up channel corresponds to uplink synchronous channel and reverse link traffic channel respectively.
Wherein, described upward signal also can only comprise uplink synchronizing signals, and described up channel is a uplink synchronous channel, and at this moment, said subscriber equipment is emitted to the base station step with filtered upward signal through up channel, comprises the steps:
Subscriber equipment is confirmed the convolution of h and h conjugation according to the conjugation of down channel impulse response h and h;
Subscriber equipment is confirmed the maximum of the convolution of said h and h conjugation;
Subscriber equipment is confirmed regularly adjustment amount according to the maximum of the convolution of h and h conjugation;
Subscriber equipment according to said timing adjustment amount to the up emission of the filtered upward signal adjustment of said process regularly;
Subscriber equipment is emitted to base station through the adjusted upward signal of timing through up channel with said.
Wherein, said subscriber equipment is confirmed regularly adjustment amount step according to the maximum of the convolution of h and h conjugation, can comprise the steps:
Setting the corresponding position p of said maximum is the possible peak of base station side that subscriber equipment is pre-estimated;
Upstream of said filtered signal transmission timing advance?
where?
rounded point to the next operation.
The present invention proposes at up channel, particularly uplink synchronous channel adopts the method for Pre-rake.Subscriber terminal equipment detects descending pilot frequency or other beacon channels; And the emission of employing Pre-rake technological adjustment up channel, particularly uplink synchronous channel; Make the base station receive certain multipath tap sets and suffered most energy, reach and improve the purpose that uplink synchronous detects performance.
Summary of drawings
Fig. 1 is the signal emission sketch map that the Pre-rake technology is adopted in the base station in the prior art;
Fig. 2 adopts the signal emission sketch map of Pre-rake technology to subscriber equipment for the present invention;
Fig. 3 is implementing procedure figure of the present invention;
Fig. 4 is the effect sketch map after the suitable good channel impulse response behind employing the present invention;
Fig. 5 is the effect sketch map after the suitable good channel impulse response convolution behind employing the present invention;
Fig. 6 is for adopting the effect sketch map that is suitable for behind the present invention behind the relatively poor channel impulse response;
Fig. 7 is for adopting the effect sketch map that is suitable for behind the present invention after the relatively poor channel impulse response convolution.
Preferred forms of the present invention
Uplink synchronous is a very crucial process, is the basis of subsequent communications, is a very important problem so how to improve the performance of uplink synchronous.To tdd communication systems, because up channel impulse response and descending impulse response have very strong correlation, subscriber equipment can be estimated the down channel impulse response, the up channel impulse response that obtains being similar to.If subscriber equipment transmits through Pre-rake adjustment like this, through after the convolution effect of channel, most emitted energies concentrate in certain (perhaps some) tap through adjusted signal.Even through decline, some tap still has higher energy.Specific energy is obviously stronger mutually with other taps in impulse response in these taps.Because the base station confirms up timing according to the tap of maximum, can make the base station tell timing information more easily so transmit, thereby make the uplink synchronous performance better through the Pre-rake adjustment.
Therefore, core thinking of the present invention is: the Pre-rake technology of employing is not in base station side, but on subscriber equipment, adopts the Pre-rake technology.
Equally, different with prior art is, it is not in order to reduce the complexity of subscriber equipment that the present invention adopts the purpose of Pre-rake technology, but in order to improve the performance of uplink synchronous.
So the present invention proposes at up channel, particularly uplink synchronous channel adopts the method for Pre-rake.Subscriber terminal equipment detects descending pilot frequency or other beacon channels; And the emission of employing Pre-rake technological adjustment up channel, particularly uplink synchronous channel; The multipath tap that the base station is received is to have concentrated most energy taps, improves the purpose that uplink synchronous detects performance to reach.
Fig. 3 is an example with uplink synchronizing signals s (t), shows practical implementation step of the present invention to be:
Step 301: subscriber equipment is estimated down channel impulse response h;
Step 302: subscriber equipment is confirmed the conjugation of h according to said down channel impulse response h;
Step 303: the uplink synchronizing signals s (t) that the subscriber equipment preparation will be launched;
Step 304: subscriber equipment carries out the filtering that is complementary with channel impulse response h to the said uplink synchronizing signals s (t) that will launch, and the filter of coupling is the conjugation of h;
Step 305: whether adopt the pre-rake technology to determine whether emission is regularly adjusted, when adopting, change step 307 over to, otherwise change step 306 over to according to the user apparatus service channel;
Step 306: The user equipment according to the downlink channel impulse response h and h the conjugate, the conjugate of h and h, the convolution; user equipment to identify the h and h, the maximum value of the convolution of the conjugate, this maximum? Corresponds position p of the user equipment may be estimated in advance of the peak position of the base station side; through said matched filter uplink synchronization signal timing advance?
where?
rounded point to the next operation.
Step 307: the uplink synchronizing signals s (t) that subscriber equipment will pass through after said timing adjustment or the unregulated matched filtering is emitted to the base station.
Step 308: the FFT conversion is perhaps done according to the uplink synchronous processing procedure to ascending pilot frequency is relevant in the base station, finds out peak, and this position is the up timing that comprises path delay.
Step 309: for synchronous CDMA system, base station physical access channel signal requires the up emission of subscriber equipment adjustment regularly so that compensating for path postpones; For the asynchronous CDMA system, the up reception of base station adjustment regularly.
Step 310: synchronous CDMA system, subscriber equipment requires on the basis of original process adjustment, to adjust once more regularly according to the base station, and adjustment amount is confirmed by the base station; The asynchronous CDMA system customer equipment is without any need for operation.Uplink synchronous is accomplished.
Wherein, for step 306, only be regularly an embodiment of adjustment algorithm; No matter it will be appreciated by those skilled in the art that regularly how adjustment algorithm is chosen, so long as according to the maximum of the convolution of h and h conjugation; Can confirm regularly adjustment amount, all should be covered by within the scope of this patent.
This shows; It is of the present invention that to focus on subscriber equipment different with existing mode to the emission process of upward signal; And after upward signal was emitted to the base station, the base station utilized existing reception synchronizing process can realize uplink synchronous, and has improved net synchronization capability simultaneously.
Subscriber equipment is adopting the pre-rake technology, and after adjustment transmitted, the upward signal energy that arrives the base station through channel was focused in one or several taps, improves the energy in the strong footpath that receives greatly, regularly the also corresponding raising of net synchronization capability.Relevant result shows, when number of channel taps is many more, the tap energy is overstepping the bounds of propriety to loose, and the gain that utilizes the pre-rake technology to obtain is big more.Effect was respectively like Fig. 4 and Fig. 5 after the present invention was suitable for good channel impulse response and convolution.When the discrete effect of less and impulse response position distribution is relatively poor in tap number, before the convolution after channel impulse response and the convolution channel impulse response respectively like Fig. 6 and shown in Figure 7.We can see with convolution before former impulse response compare, the impulse response after the convolution still has clear improvement.Because whether subscriber equipment adopts pre-rake can not influence base station and other user's communications functions; After so uplink synchronous channel adopts the situation of pre-rake technology; Even Traffic Channel does not adopt the pre-rake technology; Through the timing of adjustment subscriber equipment, not only still support normal base station synchronization, and the uplink synchronous performance is improved because of adopting the pre-rake technology.
Claims (10)
1. the upward signal launching technique of a subscriber equipment is used for the time-division duplex communication system, it is characterized in that, this method comprises the steps:
Subscriber equipment is estimated down channel impulse response h;
Subscriber equipment is confirmed the conjugation of h according to said down channel impulse response h;
The upward signal that the subscriber equipment preparation will be launched;
Subscriber equipment carries out the filtering that is complementary with channel impulse response h to the said upward signal that will launch, and the coefficient of the filter of coupling is the conjugation of h;
The upward signal that subscriber equipment will pass through behind the said filter filtering is emitted to the base station through up channel.
2. the method for claim 1 is characterized in that, described upward signal comprises uplink synchronizing signals and uplink service signal, and described up channel corresponds to uplink synchronous channel and reverse link traffic channel respectively.
3. the method for claim 1 is characterized in that, described upward signal is a uplink synchronizing signals, and described up channel is a uplink synchronous channel.
4. method as claimed in claim 3 is characterized in that said subscriber equipment is emitted to the base station step with filtered upward signal through up channel, comprises the steps:
Subscriber equipment is confirmed the convolution of h and h conjugation according to the conjugation of down channel impulse response h and h;
Subscriber equipment is confirmed the maximum of the convolution of said h and h conjugation;
Subscriber equipment is confirmed regularly adjustment amount according to the maximum of the convolution of h and h conjugation;
Subscriber equipment according to said timing adjustment amount to the up emission of the filtered upward signal adjustment of said process regularly;
Subscriber equipment is emitted to base station through the adjusted upward signal of timing through up channel with said.
5. method as claimed in claim 4 is characterized in that, said subscriber equipment is confirmed regularly adjustment amount step according to the maximum of the convolution of h and h conjugation, comprises the steps:
Setting the corresponding position p of said maximum is the possible peak of base station side that subscriber equipment is pre-estimated;
Said filtered signal transmitting uplink timing advance?
where?
rounded point to the next operation.
6. the upward signal to the subscriber equipment emission carries out regularly synchronous method, is used for the time-division duplex communication system, it is characterized in that this method comprises the steps:
Subscriber equipment is estimated down channel impulse response h;
Subscriber equipment is confirmed the conjugation of h according to said down channel impulse response h;
The upward signal that the subscriber equipment preparation will be launched;
Subscriber equipment carries out the filtering that is complementary with channel impulse response h to the said upward signal that will launch, and the coefficient of the filter of coupling is the conjugation of h;
The upward signal that subscriber equipment will pass through behind the said filter filtering is emitted to the base station through up channel;
Being correlated with or Fourier transform to the pilot tone of said upward signal in the base station, finds out peak;
According to this peak, for synchronization code multi-address division system, base station physical access channel signal; Require subscriber equipment up emission regularly to be adjusted according to the adjustment amount of confirming; So that compensating for path postpones, for the Asynchronous Code Division Multiple Access system, the up reception of base station adjustment regularly.
7. method as claimed in claim 6 is characterized in that, described upward signal comprises uplink synchronizing signals and uplink service signal, and described up channel corresponds to uplink synchronous channel and reverse link traffic channel respectively.
8. method as claimed in claim 6 is characterized in that, described upward signal is a uplink synchronizing signals, and described up channel is a uplink synchronous channel.
9. method as claimed in claim 8 is characterized in that said subscriber equipment is emitted to the base station step with filtered upward signal through up channel, comprises the steps:
Subscriber equipment is confirmed the convolution of h and h conjugation according to the conjugation of down channel impulse response h and h;
Subscriber equipment is confirmed the maximum of the convolution of said h and h conjugation;
Subscriber equipment is confirmed regularly adjustment amount according to the maximum of the convolution of h and h conjugation;
Subscriber equipment according to said timing adjustment amount to the up emission of the filtered upward signal adjustment of said process regularly;
Subscriber equipment is emitted to base station through the adjusted upward signal of timing through up channel with said.
10. method as claimed in claim 9 is characterized in that, said subscriber equipment is confirmed regularly adjustment amount step according to the maximum of the convolution of h and h conjugation, comprises the steps:
Setting the corresponding position p of said maximum is the possible peak of base station side that subscriber equipment is pre-estimated;
Said filtered signal transmitting uplink timing advance?
where?
rounded point to the next operation.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2005/001735 WO2007045127A1 (en) | 2005-10-21 | 2005-10-21 | Uplink signal transmission method for user equipment and timing synchronization method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101243622A CN101243622A (en) | 2008-08-13 |
| CN101243622B true CN101243622B (en) | 2012-05-30 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2005800513656A Expired - Fee Related CN101243622B (en) | 2005-10-21 | 2005-10-21 | Uplink signal transmitting method for user device and its method for timing synchronization |
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| Country | Link |
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| CN (1) | CN101243622B (en) |
| WO (1) | WO2007045127A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102082602B (en) * | 2009-11-30 | 2014-01-29 | 大唐移动通信设备有限公司 | Method and device for regulating air frame synchronization signal generating position |
| CN104735649A (en) * | 2015-03-25 | 2015-06-24 | 江苏物联网研究发展中心 | Wireless link signature extraction method based on Gnu Radio |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001024411A1 (en) * | 1999-09-28 | 2001-04-05 | Siemens Aktiengesellschaft | Method and system for maintaining uplink synchronization in cdma based mobile communications systems |
| WO2001089110A2 (en) * | 2000-05-15 | 2001-11-22 | University Of Bristol | Receiver with a channel estimator, a matched filter, and a decision feedback equaliser |
| WO2002063802A1 (en) * | 2001-02-07 | 2002-08-15 | Motorola, Inc. | Multi-user detection using a finite-impulse-response matrix filter |
| EP1324510A1 (en) * | 2001-12-28 | 2003-07-02 | Nokia Corporation | Downlink channel estimation method, and radio system |
-
2005
- 2005-10-21 WO PCT/CN2005/001735 patent/WO2007045127A1/en active Application Filing
- 2005-10-21 CN CN2005800513656A patent/CN101243622B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001024411A1 (en) * | 1999-09-28 | 2001-04-05 | Siemens Aktiengesellschaft | Method and system for maintaining uplink synchronization in cdma based mobile communications systems |
| WO2001089110A2 (en) * | 2000-05-15 | 2001-11-22 | University Of Bristol | Receiver with a channel estimator, a matched filter, and a decision feedback equaliser |
| WO2002063802A1 (en) * | 2001-02-07 | 2002-08-15 | Motorola, Inc. | Multi-user detection using a finite-impulse-response matrix filter |
| EP1324510A1 (en) * | 2001-12-28 | 2003-07-02 | Nokia Corporation | Downlink channel estimation method, and radio system |
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| Publication number | Publication date |
|---|---|
| WO2007045127A1 (en) | 2007-04-26 |
| CN101243622A (en) | 2008-08-13 |
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