CN1400830A - Method for reducing multicarrier signal peak level ratio - Google Patents
Method for reducing multicarrier signal peak level ratio Download PDFInfo
- Publication number
- CN1400830A CN1400830A CN 01126354 CN01126354A CN1400830A CN 1400830 A CN1400830 A CN 1400830A CN 01126354 CN01126354 CN 01126354 CN 01126354 A CN01126354 A CN 01126354A CN 1400830 A CN1400830 A CN 1400830A
- Authority
- CN
- China
- Prior art keywords
- signal
- peak
- pulse
- carrier
- level ratio
- 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.)
- Granted
Links
Images
Landscapes
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
A method of reducing peak level ratio of multi-carrier wave signals is to set a pulse signal generator in a down-stream base band or intermediate frequency modulation, to set a threshold of reducing peak level ratio on time-domain to amplitude peak value of multi-carrier wave signals; if it exceeds the threshold, then to record the character parameters of the peak value to be trans furred to each pulse generator, to generate related pulse according to above mentioned parameters and each channel of different single carrier singles making up of the multi-carrier signals, to be overlapped on the signal to cancel the peak value reduced to the threshold after combination to reduce multi-carrier signal peak level ratio. If its peak value doesn't exceed threshold, nothing can be done.
Description
(1) technical field
The present invention relates in multi-carrier broadband system descending modulation link, reduce the method for signal peak-to-average ratio.
(2) background technology
Owing to can effectively reduce the volume of base station, reduce the cost of base station, multi-transceiver technology is subjected to general attention and research at present.And people also wish in multidiameter fading channel, utilize multi-transceiver technology to realize the bit rate transmission.
But, one of shortcoming of multi-carrier communications systems is that the peak-to-average ratio that transmits also can increase when the number of subcarrier increases.Because if each single-carrier signal is all regarded as phase place cosine signal at random, the inevitable amplitude envelops of multi-carrier signal synthetic after then some single-carrier signal stacks rises and falls non-constant, and occur many higher peak values inevitably, cause the multicarrier signal peak level ratio to be higher than primary carrier signal peak-to-average ratio.
In multi-carrier signal,, then can make signal amplitude surpass the range of linearity of power amplifier at the RF end if peak-to-average ratio is bigger, producing Intermodulation Interference and signal band regenerates outward, adjacent channel is caused high interference, and make system transmissions debase, power system capacity reduces.If signal to be sent has higher peak-to-average ratio, for fear of causing out of band signal regeneration, just need power amplifier to have the bigger range of linearity, make power amplifier that bigger rollback be arranged, this can cause power amplification efficiency lower.As seen, peak-to-average ratio is excessive to be one of major reason that influences the Multi-Carrier basestation application always, and reduces the power that peak-to-average ratio can effectively increase power amplifier, improves the efficient of power amplifier, reduces to spend in the cost on the power amplifying device.
At present, reduce multicarrier signal peak level usually than following several method is generally arranged: direct amplitude limit, design spreading code, the initial phase that changes subcarrier, the outer artificial signal of superposition band etc.Directly amplitude limit can effectively reduce the signal peak-to-average ratio, but causes in-band noise to disturb easily and the regeneration of modulated signal out of band spectrum, influences adjacent channel, and then can have influence on power system capacity; For existing systems, the redesign spreading code can bring a series of problems; Change the initial phase of sub-carrier signal, operability is not strong, implements the comparison difficulty; The outer artificial signal of superposition band such as being modulated at the outer artificial amplitude-modulated signal of band, can reduce the multicarrier signal peak level ratio, but needing to spend than higher cost comes the elimination out of band signal at the radio-frequency head designing filter in real system.
(3) summary of the invention
The object of the present invention is to provide a kind of method that reduces the multicarrier signal peak level ratio, be used for the peak-to-average ratio that multi-carrier communications systems reduces base station down chain modulation signal, thereby reduce because of signal peak-to-average than the too high requirement that causes to the power amplifier range of linearity, improve the efficient of power amplifier, reduce to spend in the cost on the power amplifying device.
A kind of method that reduces the multicarrier signal peak level ratio provided by the present invention, it comprises the following steps: to be provided with a pulse signal generator in the base band of down link or intermediate frequency Modulation process; On time domain, be provided with and reduce the peak-to-average ratio thresholding, and the amplitude peak of multi-carrier signal is detected: if the multi-carrier signal amplitude peak surpasses thresholding, then write down the characteristic parameter of peak value, and these parameters are passed to a pulse signal generator; Then, according to above-mentioned parameter with constitute the different single-carrier signal in each road of multi-carrier signal, produce corresponding pulse, superposition offsets peak value on signal, make close the road after the multi-carrier signal peak value reduce to thresholding, thereby reduction multicarrier signal peak level ratio; If the multi-carrier signal amplitude peak is no more than thresholding, then do not handle.
In the method for above-mentioned reduction multicarrier signal peak level ratio, pulse is the pulse of band limit.
In the method for above-mentioned reduction multicarrier signal peak level ratio, the characteristic parameter of the peak value that writes down can be time of origin, peak height and peak phase.
In the method for above-mentioned reduction multicarrier signal peak level ratio, the pulse of band limit can be this pulse of band limit for height.
In the method for above-mentioned reduction multicarrier signal peak level ratio, the operation of superposition can be carried out in base band, also can carry out after single carrier closes the road, also can carry out after multi-carrier signal closes the road.
In the method for above-mentioned reduction multicarrier signal peak level ratio, the band-limited signal that the mode of described superposition pulse both can the superposition same magnitude, band-limited signal that also can the different amplitudes of superposition.
In the method for above-mentioned reduction multicarrier signal peak level ratio, described pulse is to have the pulse that the frequency spectrum of signal is influenced feature smaller, that attenuation ratio is bigger outside the signal bandwidth scope in bandwidth, thereby reduces the influence to the neighboring trace signal.
Owing to adopted above-mentioned technical solution, can be directly in existing systems to having the signal superposition pulse signal of higher amplitude, thereby reduction multicarrier signal peak level ratio.Particularly the pulse of superposition band limit can be so that the frequency spectrum influence to signal be smaller in bandwidth, and attenuation ratio is bigger outside the signal bandwidth scope, can not cause the regeneration of modulated signal out of band spectrum, thereby the neighboring trace effect of signals is reduced greatly.This band limit pulse time of origin on time domain is short, can not make the later signal of superposition band limit pulse signal the peak value of new high-amplitude occur, and easy operating, implement the cost that spends less relatively.
(4) description of drawings
Fig. 1 (a), Fig. 1 (b) have increased the signal processing flow figure behind the pulse signal generator in the base station;
Fig. 2 is the flow chart that the first embodiment of the present invention is handled signal;
Fig. 3 is the flow chart that the second embodiment of the present invention is handled signal;
Fig. 4 is the flow chart that the third embodiment of the present invention is handled signal.
(5) embodiment
Shown in Fig. 1 (a), on each bar single carrier down link, the sequence of complex-valued chips that produces by spread spectrum separately becomes real part and imaginary part 2 road signals after by deserializer 11, and this 2 road signal passes through root raised cosine filter 12 respectively and carries out pulse-shaping, to reduce intersymbol interference.
Multiply each other in multiplier 14 through 2 road signals of pulse-shaping and 2 tunnel CF signal of digital controlled oscillator 13 generations, carry out intermediate frequency Modulation.This 2 tunnel signal that has been modulated to intermediate frequency respectively closes the road by adder 15.The carrier frequency that it should be noted that each bar single carrier down link is mutually different, and promptly in each bar single carrier down link, the frequency of the CF signal that digital controlled oscillator 13 produces is different.
Signal addition in adder 16 that each bar single carrier down link produces becomes the multi-transceiver combination signal.
This multi-transceiver combination signal is sent in the band limit pulse generator 17 and detects, and band limit pulse generator 17 produces corresponding band limit pulse signal, reduces the processing of peak-to-average ratio.
Shown in Fig. 1 (b), on each bar single carrier down link, the sequence of complex-valued chips that produces by spread spectrum separately becomes real part and imaginary part 2 road signals after by deserializer 11, and this 2 road signal passes through root raised cosine filter 12 respectively and carries out pulse-shaping, to reduce intersymbol interference.
Band limit pulse generator 17 produces corresponding band limit pulse signal, reduces the processing of peak-to-average ratio.
2 tunnel CF signal that 2 road signals and digital controlled oscillator 13 produce multiply each other in multiplier 14, carry out intermediate frequency Modulation.This 2 tunnel signal that has been modulated to intermediate frequency respectively closes the road by adder 15.The carrier frequency of each bar single carrier down link is mutually different, and promptly in each bar single carrier down link, the frequency of the CF signal that digital controlled oscillator 13 produces is different.
Signal addition in adder 16 that each bar single carrier down link produces becomes the multi-transceiver combination signal.
Introduce first embodiment of the inventive method below.
As shown in Figure 2, the flow chart of in this pulse generator of band limit for height signal being handled among first embodiment.
With reference to Fig. 1, can realize with software with the process that reduces peak-to-average ratio this pulse of multi-carrier signal superposition band limit for height among first embodiment.Its processing procedure as shown in Figure 2.
The amplitude of unit 21 input multi-carrier signals is compared signal amplitude X in unit 22 with reduction peak-to-average ratio thresholding (Threshold).If X＜Threshold does not then do any processing, directly deliver to output in the unit 25; If X＞Threshold, the parameter of tracer signal amplitude in unit 23 then, the moment of taking place such as amplitude peak, the height of peak value etc.These parameters are imported in the unit 24, and this pulse generator of band limit for height is with this pulse of limit for height accordingly according to these parameter generating, and superposition makes the amplitude of multi-carrier signal reduce to desired thresholding on multi-carrier signal.
It is each when peak value appears in multi-carrier signal, corresponding modulated this pulse of band limit for height of picked at random one tunnel single-carrier signal superposition, and all the other branch road single-carrier signal are not processed, the final amplitude that reduces peak-to-average ratio multi-carrier signal afterwards that makes is reduced to the thresholding that sets.
The amplitude that is used for this pulse of modulated band limit for height of superposition
=(exceeding the multi-carrier signal peak value amplitude-reduction peak-to-average ratio thresholding that reduces peak-to-average ratio thresholding place)
Be sent to unit 25 outputs through the signal that reduces the peak-to-average ratio processing.
More than first kind of embodiment of the inventive method is described.Introduce second of the inventive method below
Embodiment.
As shown in Figure 3, the flow chart of in this pulse generator of band limit for height signal being handled among second embodiment.
With reference to Fig. 1, can realize with software with the process that reduces peak-to-average ratio this Gaussian pulse of multi-carrier signal superposition band limit for height.Its processing procedure as shown in Figure 3.
The amplitude of unit 31 input multi-carrier signals is compared signal amplitude X in unit 32 with reduction peak-to-average ratio thresholding Threshold.If X＜Threshold does not then do any processing, directly deliver to output in the unit 35; If X＞Threshold, the parameter of tracer signal amplitude in unit 33 then, the moment of taking place such as amplitude peak, the height of peak value etc.These parameters are imported in the unit 34, and this pulse generator of band limit for height is with the limit pulse accordingly according to these parameter generating, and superposition makes the amplitude of multi-carrier signal reduce to desired thresholding on multi-carrier signal.
Add modulated this pulse of band limit for height for each the road single-carrier signal that constitutes multi-carrier signal, the amplitude of modulated band limit for height this pulse of superposition on each road single-carrier signal is identical, makes the amplitude that reduces peak-to-average ratio multi-carrier signal afterwards reduce to the thresholding that sets.Promptly
The amplitude of each road this pulse of modulated band limit for height
=(exceeding the peak amplitude-reduction peak-to-average ratio thresholding that reduces peak-to-average ratio thresholding place multi-carrier signal)/carrier number
Be sent to unit 35 outputs through the signal that reduces the peak-to-average ratio processing.
More than second kind of embodiment of the inventive method is described.Introduce the 3rd of the inventive method below
Embodiment.
As shown in Figure 4, the flow chart of in this pulse generator of band limit for height signal being handled among the 3rd embodiment.
With reference to Fig. 1, can realize with software with the process that reduces peak-to-average ratio this pulse of multi-carrier signal superposition band limit for height.Its processing procedure as shown in Figure 4.
The amplitude of unit 41 input multi-carrier signals is compared signal amplitude X in unit 42 with reduction peak-to-average ratio thresholding Threshold.If X＜Threshold does not then do any processing, directly deliver to output in the unit 45; If X＞Threshold, the parameter of tracer signal amplitude in unit 43 then, the moment of taking place such as amplitude peak, the height of peak value etc.These parameters are imported in the unit 44, and this pulse generator of band limit for height is with this pulse of limit for height accordingly according to these parameter generating, and superposition makes the amplitude of multi-carrier signal reduce to desired thresholding on multi-carrier signal.
Add modulated this pulse of band limit for height for each the road single-carrier signal that constitutes multi-carrier signal, the amplitude of modulated band limit for height this pulse of superposition on each road single-carrier signal is incomplete same.For the higher relatively single carrier branch road of amplitude, modulated this pulse amplitude of band limit for height of superposition is higher; Hang down the single carrier branch road of some relatively for amplitude, modulated this pulse amplitude of band limit for height of superposition is lower.The amplitude information of each single carrier branch road can extract before being multi-carrier signal closing the road, and pass to band Gauss as the input parameter and limit pulse generator, as choosing the foundation of band limit for height this pulse amplitude of superposition on each road single-carrier signal respectively, the final amplitude that reduces peak-to-average ratio multi-carrier signal afterwards that makes is reduced to the thresholding that sets.Promptly
The amplitude of each road this pulse of modulated band limit for height
=(the multi-carrier signal peak value amplitude-reduction peak-to-average ratio thresholding that exceeds reduction peak-to-average ratio thresholding place) * (this locates the amplitude peak of this road single-carrier signal constantly)/(this locates the amplitude peak of multi-carrier signal constantly)
Be sent to unit 45 outputs through the signal that reduces the peak-to-average ratio processing.
Superposition is band limit for height this pulse on multi-carrier signal in above embodiment.This pulse frequency spectrum influence to signal in bandwidth is smaller, and attenuation ratio is bigger outside the signal bandwidth scope, can not cause the regeneration of modulated signal out of band spectrum, thereby the neighboring trace effect of signals is reduced greatly.This band limit pulse time of origin on time domain is short, can not make the later signal of superposition band limit pulse signal the peak value of new high-amplitude occur.The producing method of this pulse is simple, easy operating.
Claims (7)
1. method that reduces the multicarrier signal peak level ratio, it comprises the following steps:
In the base band of down link or intermediate frequency Modulation process, a pulse signal generator is set;
On time domain, be provided with and reduce the peak-to-average ratio thresholding, and the amplitude peak of multi-carrier signal is detected:
If the multi-carrier signal amplitude peak surpasses thresholding, then write down the characteristic parameter of peak value, and these parameters are passed to a pulse signal generator;
Then, according to above-mentioned parameter with constitute the different single-carrier signal in each road of multi-carrier signal, produce corresponding pulse, superposition offsets peak value on signal, make close the road after the multi-carrier signal peak value reduce to thresholding, thereby reduction multicarrier signal peak level ratio;
If the multi-carrier signal amplitude peak is no more than thresholding, then do not handle.
2. a kind of method that reduces the multicarrier signal peak level ratio according to claim 1 is characterized in that, described pulse is the pulse of band limit.
3. a kind of method that reduces the multicarrier signal peak level ratio according to claim 1 is characterized in that the characteristic parameter of the peak value that writes down can be time of origin, peak height and peak phase.
4. a kind of method that reduces the multicarrier signal peak level ratio according to claim 2 is characterized in that, the pulse of described band limit can be this pulse of band limit for height.
5. a kind of method that reduces the multicarrier signal peak level ratio according to claim 1 is characterized in that the operation of described superposition can be carried out in base band, also can carry out after single carrier closes the road, also can carry out after multi-carrier signal closes the road.
6. a kind of method that reduces the multicarrier signal peak level ratio according to claim 1 is characterized in that, the band-limited signal that the mode of described superposition pulse both can the superposition same magnitude, band-limited signal that also can the different amplitudes of superposition.
7. a kind of method that reduces the multicarrier signal peak level ratio according to claim 1, it is characterized in that, described pulse is to have the pulse that the frequency spectrum of signal is influenced feature smaller, that attenuation ratio is bigger outside the signal bandwidth scope in bandwidth, thereby reduces the influence to the neighboring trace signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011263547A CN1154384C (en) | 2001-07-27 | 2001-07-27 | Method for reducing multicarrier signal peak level ratio |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011263547A CN1154384C (en) | 2001-07-27 | 2001-07-27 | Method for reducing multicarrier signal peak level ratio |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1400830A true CN1400830A (en) | 2003-03-05 |
| CN1154384C CN1154384C (en) | 2004-06-16 |
Family
ID=4666374
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB011263547A Expired - Fee Related CN1154384C (en) | 2001-07-27 | 2001-07-27 | Method for reducing multicarrier signal peak level ratio |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1154384C (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009010010A1 (en) * | 2007-07-17 | 2009-01-22 | Huawei Technologies Co., Ltd. | A method and device of clipping process of signal |
| CN101146085B (en) * | 2006-09-14 | 2010-08-11 | 大唐移动通信设备有限公司 | A method and device for eliminating time slot edge peak power |
| CN1972263B (en) * | 2005-11-23 | 2010-12-08 | 中兴通讯股份有限公司 | A multi-carrier communication system |
| CN1972179B (en) * | 2005-11-23 | 2010-12-29 | 中兴通讯股份有限公司 | A generation method for multi-carrier signal |
| CN101232483B (en) * | 2007-01-22 | 2011-08-17 | 大唐移动通信设备有限公司 | Processing method and apparatus in the course of cutting peak power |
| CN102273161A (en) * | 2009-01-06 | 2011-12-07 | 高通股份有限公司 | Multi-carrier transmission over a single frequency band |
| CN101120563B (en) * | 2004-12-21 | 2013-05-08 | 艾利森电话股份有限公司 | Transmitter device and method for transmitting packet data units in communication system |
| US8451943B2 (en) | 2009-06-22 | 2013-05-28 | Huawei Technologies Co., Ltd. | Method and device for transmitting signal |
| CN104767493A (en) * | 2015-02-28 | 2015-07-08 | 联想(北京)有限公司 | Method and system for processing information |
| CN107395330A (en) * | 2017-08-28 | 2017-11-24 | 珠海市杰理科技股份有限公司 | The method, apparatus and computer equipment of Low Medium Frequency carrier wave detection |
-
2001
- 2001-07-27 CN CNB011263547A patent/CN1154384C/en not_active Expired - Fee Related
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101120563B (en) * | 2004-12-21 | 2013-05-08 | 艾利森电话股份有限公司 | Transmitter device and method for transmitting packet data units in communication system |
| CN1972263B (en) * | 2005-11-23 | 2010-12-08 | 中兴通讯股份有限公司 | A multi-carrier communication system |
| CN1972179B (en) * | 2005-11-23 | 2010-12-29 | 中兴通讯股份有限公司 | A generation method for multi-carrier signal |
| CN101146085B (en) * | 2006-09-14 | 2010-08-11 | 大唐移动通信设备有限公司 | A method and device for eliminating time slot edge peak power |
| CN101232483B (en) * | 2007-01-22 | 2011-08-17 | 大唐移动通信设备有限公司 | Processing method and apparatus in the course of cutting peak power |
| CN101076008B (en) * | 2007-07-17 | 2010-06-09 | 华为技术有限公司 | Method and apparatus for processing clipped wave |
| WO2009010010A1 (en) * | 2007-07-17 | 2009-01-22 | Huawei Technologies Co., Ltd. | A method and device of clipping process of signal |
| CN102273161A (en) * | 2009-01-06 | 2011-12-07 | 高通股份有限公司 | Multi-carrier transmission over a single frequency band |
| US8594155B2 (en) | 2009-01-06 | 2013-11-26 | Qualcomm Incorporated | Multi-carrier transmitter design on adjacent carriers in a single frequency band on the uplink in W-CDMA/HSPA |
| CN102273161B (en) * | 2009-01-06 | 2014-12-10 | 高通股份有限公司 | Multi-carrier transmission method and device over a single frequency band |
| US8451943B2 (en) | 2009-06-22 | 2013-05-28 | Huawei Technologies Co., Ltd. | Method and device for transmitting signal |
| CN104767493A (en) * | 2015-02-28 | 2015-07-08 | 联想(北京)有限公司 | Method and system for processing information |
| CN104767493B (en) * | 2015-02-28 | 2018-01-23 | 联想(北京)有限公司 | A kind of information processing method and system |
| CN107395330A (en) * | 2017-08-28 | 2017-11-24 | 珠海市杰理科技股份有限公司 | The method, apparatus and computer equipment of Low Medium Frequency carrier wave detection |
| CN107395330B (en) * | 2017-08-28 | 2020-07-03 | 珠海市杰理科技股份有限公司 | Method and device for detecting low-intermediate frequency carrier wave and computer equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1154384C (en) | 2004-06-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jiang et al. | On the nonlinear companding transform for reduction in PAPR of MCM signals | |
| CN101136890B (en) | Optimized multi-carrier signal slicing device and method therefor | |
| US6845082B2 (en) | Peak to average power ratio reduction in communication systems | |
| DE602004001266T2 (en) | Method and apparatus for reducing the ratio of peak power to average power | |
| KR100754621B1 (en) | Method and apparatus for the papr reduction using pre-emphasis method in ofdm wireless communication system | |
| CN100502378C (en) | Circuit and method of peak-to-average ratio suppression in OFDM system | |
| CN1359245A (en) | Method for amplitude-limited wide-band radio signal and relative transmitter | |
| CN1154384C (en) | Method for reducing multicarrier signal peak level ratio | |
| US7924941B2 (en) | Digital pre-distortion for orthogonal frequency division multiplexing (OFDM) signals | |
| CN1367615A (en) | Time-domain synchronous orthogonal frequency division multiplex modulation method of low peak average power ratio | |
| CN105553909B (en) | A kind of method that iteration limit filtration reduces ofdm signal peak-to-average force ratio | |
| CN114966584A (en) | OFDM radar communication integrated peak-to-average ratio inhibition method based on improved amplitude limiting method | |
| CN102404272A (en) | System and a method for processing wireless signals based on coded orthogonal frequency division multiplexing | |
| CN1389035A (en) | Multicarrier transmitter and multicarrier transmission method | |
| CN1741517A (en) | Block clipping method for resolving nonlinear distortion question in OFDM system | |
| US7974354B2 (en) | Peak-to-average-power-ratio reduction in communication systems | |
| CN1777087A (en) | MC-CDMA system transmitting and receiving method | |
| Sakran et al. | An efficient technique for reducing PAPR of OFDM system in the presence of nonlinear high power amplifier | |
| CN115001917B (en) | Modulation signal generation method for radar communication integration | |
| Hu et al. | Performance Analysis of OFDM and FBMC | |
| CN106161320A (en) | A kind of self-adapting compressing expansion technique reduces the method for ofdm system PAPR | |
| Kumar et al. | PAPR Reduction Using Advanced Partial Transmission Scheme for 5G Waveforms. | |
| CN105721056B (en) | One kind reduces visible light communication system light source led non-linear method and system | |
| CN104994051A (en) | IAPR-based linear scaling change signal transmitting and receiving method for improving PA efficiency of hybrid carrier system | |
| CN1177425C (en) | Peak power inhibiting method and device suitable for CDMA communication 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 | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20040616 Termination date: 20170727 |