CN103747517A - Frequency synchronizing method and device - Google Patents
Frequency synchronizing method and device Download PDFInfo
- Publication number
- CN103747517A CN103747517A CN201410033403.6A CN201410033403A CN103747517A CN 103747517 A CN103747517 A CN 103747517A CN 201410033403 A CN201410033403 A CN 201410033403A CN 103747517 A CN103747517 A CN 103747517A
- Authority
- CN
- China
- Prior art keywords
- burst
- compensation
- frequency
- phase
- phase deviation
- 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
- Synchronisation In Digital Transmission Systems (AREA)
Abstract
The invention relates to the field of communication, in particular to a frequency synchronizing method and device. The frequency synchronizing method comprises the following steps: extracting a burst head from a burst signal; performing frequency deviation estimation and phase deviation estimation on the burst head; performing frequency deviation compensation on a received burst signal by using the frequency deviation estimation, and performing phase deviation compensation on the received burst signal by using the phase deviation estimation; extracting unique characters from the burst signal subjected to the phase deviation compensation; performing phase fuzzy elimination on the burst signal subjected to phase compensation by using the unique characters, and synchronizing the frequency. The frequency synchronizing device comprises a first extracting module, an estimating module, a first compensating module, a second extracting module and a processing module. By adopting the frequency synchronizing method and the device, the frequency and phase deviation estimation are performed by using a non-data-aided method without using the unique characters, so that the problem of low estimation accuracy in case of a small quantity of unique characters is solved.
Description
Technical field
The present invention relates to the communications field, be specifically related to a kind of frequency synchronization method and device.
Background technology
Along with the development of information communication industry, China's land mobile communication system is more flourishing.Yet because China is vast in territory, geographical environment is various, population distribution is uneven, land mobile communication system has only covered the area of China 30%, also remaining 70% area lacks basic communication support.Satellite mobile communication system can effectively be expanded its coverage via satellite, so that can in the world user terminal be accessed to public or private wire network.Therefore, satellite mobile communication system is as an important component part of ICT industry, in national information infrastructure construction, promote national disaster prevention emergency ability, safeguard that the aspects such as national unipolitics economic interests have critical role.
In satellite mobile communication system, due to the unsteadiness of local crystal oscillator frequency, and the Doppler frequency shift that causes of relatively moving between terminal and satellite, can cause receiving between the frequency of signal and the frequency of local crystal oscillator and have certain deviation.Particularly aviation terminal, its translational speed maximum can reach 1000 kilometers/hour, thereby causes larger frequency departure.Only have and estimate accurately this frequency departure and compensate, just can carry out the normal mediation decoding of separating.Therefore,, in satellite mobile communication system, Frequency Synchronization is the key that realizes the normal prerequisite receiving and improve systematic function.
For the lower problem of the synchronous ratio of precision of correlation technique medium frequency, solution is not proposed so far.
Summary of the invention
In order to achieve the above object, a kind of frequency synchronization method and the device of providing of the present invention.
According to an aspect of the present invention, provide a kind of frequency synchronization method, be included in extraction burst head in burst; Described burst head is carried out to frequency offset estimation and phase deviation estimation; Use described frequency offset estimation to carry out frequency departure compensation to the burst receiving, under using, phase deviation estimates the described burst receiving to carry out phase deviation compensation; From the burst described phase deviation compensation, extract unique word; Burst after using described unique word to phase compensation carries out phase ambiguity elimination, carries out Frequency Synchronization.
Preferably, after the described frequency offset estimation of use carries out frequency compensation to the burst receiving, also comprise: use non-data-aided method to carry out phase deviation estimation to the described frequency compensation burst afterwards that carries out; Under using, phase deviation estimates the burst after affiliated frequency departure compensation to carry out phase deviation compensation.
Preferably, the burst after using described unique word to phase compensation carries out phase ambiguity elimination, carries out Frequency Synchronization and comprises: the described unique word extracting and local unique word are carried out to relevant treatment and obtain phase ambiguity detected value; Burst after using described phase ambiguity detected value to described phase deviation compensation carries out phase ambiguity elimination.
The embodiment of the present invention provides a kind of frequency synchronization device, comprising: the first extraction module, for extract burst head at burst; Estimation module, for carrying out frequency offset estimation and phase deviation estimation to described burst head; The first compensating module, for using described frequency offset estimation to carry out frequency departure compensation to the burst receiving, under using, phase deviation estimates the described burst receiving to carry out phase deviation compensation; The second extraction module, extracts unique word for the burst from described phase deviation compensation; Processing module, carries out phase ambiguity elimination for the burst after using described unique word to phase compensation, carries out Frequency Synchronization.
Preferably, described device, also comprises: estimation module, for using non-data-aided method to carry out phase deviation estimation to the described frequency compensation burst afterwards that carries out; The second compensating module, estimates the burst after affiliated frequency departure compensation to carry out phase deviation compensation for phase deviation under using.
Preferably, affiliated processing module comprises: the first processing unit, obtains phase ambiguity detected value for the described unique word extracting and local unique word are carried out to relevant treatment; The second processing unit, carries out phase ambiguity elimination for the burst after using described phase ambiguity detected value to described phase deviation compensation.
By the present invention, adopt non-data-aided method to carry out frequency and phase deviation and estimate, and do not need to use unique word, solved unique word symbolic number lower problem of accuracy of estimation when less.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is some embodiments of the present invention, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the flow chart according to frequency synchronization method of the present invention;
Fig. 2 is according to the structural representation of PNB2 of the present invention (5,3) burst;
Fig. 3 is according to simulation result schematic diagram of the present invention.
Embodiment
For making object, technical scheme and the advantage of the embodiment of the present invention clearer, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.Embodiment based in the present invention, those of ordinary skills, not making the every other embodiment obtaining under creative work prerequisite, belong to the scope of protection of the invention.
Below in conjunction with preferred embodiment, be elaborated.
This preferred embodiment provides a kind of frequency synchronization method, and Fig. 1 is the flow chart according to frequency synchronization method of the present invention, and as shown in Figure 1, the method comprises the steps that S101 is to step S108.
S101, burst head extracts: from burst, extract burst head, for frequency and phase deviation, estimate.
S102, frequency offset estimation: utilize burst head, adopt non-data-aided method to carry out frequency offset estimation.
S103, frequency departure compensation: according to frequency offset estimation value, the burst receiving is carried out to frequency departure compensation.
S104, phase deviation is estimated: because the burst after frequency departure compensation still exists random phase deviation, utilize burst head, adopt non-data-aided method to carry out phase deviation estimation.
S105, phase deviation compensation: according to phase deviation estimated value, the burst after frequency departure compensation is carried out to phase deviation compensation.
S106, unique word extracts: the unique word in the burst after phase deviation compensation is extracted, for phase ambiguity, estimate.
S107, phase ambiguity detects: because the burst after phase deviation compensation may exist phase ambiguity, utilize unique word, adopt the method relevant to local unique word to carry out phase ambiguity detection.
S108, phase ambiguity is eliminated: according to phase ambiguity detected value, the burst after phase deviation compensation is carried out to phase ambiguity elimination, thereby realize accurately Frequency Synchronization.
This preferred embodiment provides a kind of frequency synchronization method, and the scene in the preferred embodiment is as follows: in certain geosynchronous earth orbit satellite mobile communication system, signal frame adopts the structure of time division multiplexing (TDMA).Each superframe comprises 4 multi-frames, and each multi-frame comprises 16 tdma frames, and each tdma frame comprises again 24 time slots, and each time slot comprises 39 symbols.
Different logic channels adopts different bursts.For example, packet data traffic channel PDTCH2 (5,3) takies 5 subcarriers, 3 time slots, and the structure of the PNB2 of employing (5,3) burst as shown in Figure 2.Wherein, burst head (Burst Header) is front; comprise protection interval (Guard), unique word (UW), public information (PUI) and burst transition (TR), remainder comprises personal information (PRI), unique word (UW) and protection interval (Guard).Burst head adopts QPSK modulation, and personal information (PRI) can adopt QPSK, 16APSK or 32APSK modulation according to system requirements.
Be elaborated below.
Step S201, burst head extracts
From burst, extract burst head, for frequency and phase deviation, estimate.
If the burst receiving is r (k), k=0,1 ..., K-1, the burst head extracting from burst r (k) is x (n), n=0,1 ..., N-1, wherein K is burst symbolic number, N is a burst symbolic number.For PNB2 (5,3) burst, K=585, N=66.
Step S202, frequency offset estimation
Utilize burst head, adopt non-data-aided method to carry out frequency offset estimation.
A burst x (n) is carried out to the processing of M power, obtain x
m(n), n=0,1 ..., N.Because burst head adopts QPSK modulation, M=4, can effectively reduce the complexity of calculating.
To x
m(n) carry out front and back auto-correlation, obtain auto-correlation function
Frequency offset estimation value can be obtained by auto-correlation function R (m)
Wherein arg () represents to get phase place, T
sfor the symbol time cycle, parameter D can carry out suitable choosing according to the required scope of frequency offset estimation.
Step S203, frequency departure compensation
According to frequency offset estimation value Δ f, burst r (k) is carried out to frequency departure compensation, obtain the burst after frequency departure compensation
s(k)=r(k)exp(-j2πΔfkT
S),k=0,1,...,K-1
Step S204, phase deviation is estimated.
Because the burst after frequency departure compensation still exists random phase deviation, utilize burst head, adopt non-data-aided method to carry out phase deviation estimation.
If the burst head extracting from burst s (k) is y (n), n=0,1 ..., N-1.
A burst y (n) is carried out to the processing of M power, obtain y
m(n), n=0,1 ..., N.Because burst head adopts QPSK modulation, M=4, can effectively reduce the complexity of calculating.
Phase deviation estimated value can be by y
m(n) obtain
Step S105, phase deviation compensation.
According to phase deviation estimated value
burst s (k) after frequency departure compensation is carried out to phase deviation compensation, obtain the burst after phase deviation compensation
Step S106, unique word extracts.
Unique word in burst after phase deviation compensation is extracted, for phase ambiguity, estimate.
If the unique word extracting from burst t (k) is z (l), l=0,1 ..., L-1, wherein L is unique word symbolic number.For PNB2 (5,3) burst, L=25,14 or 13.
Step S107, phase ambiguity detects.
Because the burst after phase deviation compensation may exist phase ambiguity, utilize unique word, adopt the method relevant to local unique word to carry out phase ambiguity detection.
By the unique word z (l) extracting and local unique word u (l), l=0,1 ..., L-1 carries out cross-correlation, and correlation is carried out to phase rotating
Phase ambiguity value can obtain by the real part size of the postrotational correlation C of detected phase (i)
I:C(I)=max(real(C(i))),i=0,1,...,M-1
Wherein, real () represents to get real part, and max () represents to get maximum.
Step S108, phase ambiguity is eliminated.
According to phase ambiguity detected value I, the burst t (k) after phase deviation compensation is carried out to phase ambiguity elimination
Thereby realize accurately Frequency Synchronization.
By the technical scheme in above-described embodiment and preferred embodiment, under additive white Gaussian noise (AWGN) channel, when frequency departure is 35Hz, adopt said method to carry out, after frequency offset estimation and compensation, phase deviation estimation and compensation and phase ambiguity detection and elimination, receiving the error sign ratio of burst as shown in Figure 3.Can find out, adopt performance after said frequencies synchronous method almost consistent with the theoretical performance during without frequency departure under awgn channel.
The present embodiment provides a kind of frequency synchronization device, below this device is described in detail.
According to another aspect of the invention, also provide a kind of frequency synchronization device, having comprised: the first extraction module, for extract burst head at burst; Estimation module, for carrying out frequency offset estimation and phase deviation estimation to described burst head; The first compensating module, for using described frequency offset estimation to carry out frequency departure compensation to the burst receiving, under using, phase deviation estimates the described signal receiving to carry out phase deviation compensation; The second extraction module, extracts unique word for the burst from described phase deviation compensation; Processing module, carries out phase ambiguity elimination for the burst after using described unique word to phase compensation, carries out Frequency Synchronization.
Preferably, said apparatus also comprises: estimation module, for using non-data-aided method to carry out phase deviation estimation to the described frequency compensation burst afterwards that carries out; The second compensating module, estimates the burst after affiliated frequency departure compensation to carry out phase deviation compensation for phase deviation under using.
Preferably, affiliated processing module comprises: the first processing unit, obtains phase ambiguity detected value for the unique word of described extraction and local unique word are carried out to relevant treatment; The second processing unit, carries out phase ambiguity elimination for the burst after using described phase ambiguity detected value to described phase deviation compensation.
By technique scheme of the present invention, adopt non-data-aided method to carry out frequency and phase deviation and estimate, and do not need to use unique word, solved unique word symbolic number lower problem of accuracy of estimation when less.Utilize the burst head of low-order-modulated to carry out frequency and phase deviation estimation, can effectively reduce the complexity of calculating.Only need to use a small amount of unique word to carry out phase ambiguity elimination, can realize accurately Frequency Synchronization.It should be noted that, the application's technical scheme can be widely used in various satellite mobile communication systems.
One of ordinary skill in the art will appreciate that: all or part of step that realizes said method embodiment can complete by the relevant hardware of program command, aforesaid program can be stored in a computer read/write memory medium, this program, when carrying out, is carried out the step that comprises said method embodiment; And aforesaid storage medium comprises: various media that can be program code stored such as ROM, RAM, magnetic disc or CDs.
Finally it should be noted that: above embodiment only, in order to technical scheme of the present invention to be described, is not intended to limit; Although the present invention is had been described in detail with reference to previous embodiment, those of ordinary skill in the art is to be understood that: its technical scheme that still can record aforementioned each embodiment is modified, or part technical characterictic is wherein equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution depart from the spirit and scope of various embodiments of the present invention technical scheme.
Claims (6)
1. a frequency synchronization method, is characterized in that, comprising:
In burst, extract burst head;
Described burst head is carried out to frequency offset estimation and phase deviation estimation;
Use described frequency offset estimation to carry out frequency departure compensation to the burst receiving, under using, phase deviation estimates the described burst receiving to carry out phase deviation compensation;
From the burst described phase deviation compensation, extract unique word;
Burst after using described unique word to phase compensation carries out phase ambiguity elimination, carries out Frequency Synchronization.
2. method according to claim 1, is characterized in that, after the described frequency offset estimation of use carries out frequency compensation to the burst receiving, also comprises:
Use non-data-aided method to carry out phase deviation estimation to the described frequency compensation burst afterwards that carries out;
Under using, phase deviation estimates the burst after affiliated frequency departure compensation to carry out phase deviation compensation.
3. method according to claim 1, is characterized in that, the burst after using described unique word to phase compensation carries out phase ambiguity elimination, carries out Frequency Synchronization and comprises:
The described unique word extracting and local unique word are carried out to relevant treatment and obtain phase ambiguity detected value;
Burst after using described phase ambiguity detected value to described phase deviation compensation carries out phase ambiguity elimination.
4. a frequency synchronization device, is characterized in that, comprising:
The first extraction module, for extracting burst head at burst;
Estimation module, for carrying out frequency offset estimation and phase deviation estimation to described burst head;
The first compensating module, for using described frequency offset estimation to carry out frequency departure compensation to the burst receiving, under using, phase deviation estimates the described burst receiving to carry out phase deviation compensation;
The second extraction module, extracts unique word for the burst from described phase deviation compensation;
Processing module, carries out phase ambiguity elimination for the burst after using described unique word to phase compensation, carries out Frequency Synchronization.
5. device according to claim 4, is characterized in that, also comprises:
Estimation module, for being used non-data-aided method to carry out phase deviation estimation to the described frequency compensation burst afterwards that carries out;
The second compensating module, estimates the burst after affiliated frequency departure compensation to carry out phase deviation compensation for phase deviation under using.
6. device according to claim 4, is characterized in that, affiliated processing module comprises:
The first processing unit, obtains phase ambiguity detected value for the described unique word extracting and local unique word are carried out to relevant treatment;
The second processing unit, carries out phase ambiguity elimination for the burst after using described phase ambiguity detected value to described phase deviation compensation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410033403.6A CN103747517B (en) | 2014-01-23 | 2014-01-23 | frequency synchronization method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410033403.6A CN103747517B (en) | 2014-01-23 | 2014-01-23 | frequency synchronization method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103747517A true CN103747517A (en) | 2014-04-23 |
| CN103747517B CN103747517B (en) | 2018-06-08 |
Family
ID=50504490
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410033403.6A Active CN103747517B (en) | 2014-01-23 | 2014-01-23 | frequency synchronization method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103747517B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104601506A (en) * | 2014-10-10 | 2015-05-06 | 中国电子科技集团公司第四十一研究所 | Non-data aided OQPSK (Offset Quadra Phase Shift Keying) signal closed loop carrier synchronization method |
| CN105743563A (en) * | 2016-04-21 | 2016-07-06 | 中国电子科技集团公司第五十四研究所 | Demodulation method for DKAB (Dual Keep Alive Burst) of satellite mobile communication system |
| CN110831147A (en) * | 2019-11-08 | 2020-02-21 | 北京邮电大学 | Carrier frequency synchronization method suitable for millimeter wave intersatellite link |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6606363B1 (en) * | 1999-12-28 | 2003-08-12 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and apparatus for estimating a frequency offset by combining pilot symbols and data symbols |
| CN101553028A (en) * | 2009-04-30 | 2009-10-07 | 西南交通大学 | Frequency offset and phase estimation method based on differential phase in TD-SCDMA communication system receiving synchronization |
| CN101588333A (en) * | 2008-05-22 | 2009-11-25 | 赵力 | Synchronization method suitable for terrestrial broadcasting national standard of Chinese digital televisions |
| CN101626357A (en) * | 2009-09-22 | 2010-01-13 | 北京理工大学 | Carrier synchronization method of MPSK system based on maximum likelihood estimation |
| CN102075486A (en) * | 2011-01-20 | 2011-05-25 | 深圳市阿派斯实业有限公司 | Synchronized method of orthogonal frequency division multiplexing (OFDM) system |
-
2014
- 2014-01-23 CN CN201410033403.6A patent/CN103747517B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6606363B1 (en) * | 1999-12-28 | 2003-08-12 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and apparatus for estimating a frequency offset by combining pilot symbols and data symbols |
| CN101588333A (en) * | 2008-05-22 | 2009-11-25 | 赵力 | Synchronization method suitable for terrestrial broadcasting national standard of Chinese digital televisions |
| CN101553028A (en) * | 2009-04-30 | 2009-10-07 | 西南交通大学 | Frequency offset and phase estimation method based on differential phase in TD-SCDMA communication system receiving synchronization |
| CN101626357A (en) * | 2009-09-22 | 2010-01-13 | 北京理工大学 | Carrier synchronization method of MPSK system based on maximum likelihood estimation |
| CN102075486A (en) * | 2011-01-20 | 2011-05-25 | 深圳市阿派斯实业有限公司 | Synchronized method of orthogonal frequency division multiplexing (OFDM) system |
Non-Patent Citations (1)
| Title |
|---|
| 刘世刚: "短波突发信号盲接收技术研究", 《中国博士学位论文全文数据库》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104601506A (en) * | 2014-10-10 | 2015-05-06 | 中国电子科技集团公司第四十一研究所 | Non-data aided OQPSK (Offset Quadra Phase Shift Keying) signal closed loop carrier synchronization method |
| CN104601506B (en) * | 2014-10-10 | 2017-10-03 | 中国电子科技集团公司第四十一研究所 | A kind of OQPSK signal closed loop carrier synchronization methods of unbound nucleus |
| CN105743563A (en) * | 2016-04-21 | 2016-07-06 | 中国电子科技集团公司第五十四研究所 | Demodulation method for DKAB (Dual Keep Alive Burst) of satellite mobile communication system |
| CN105743563B (en) * | 2016-04-21 | 2018-10-09 | 中国电子科技集团公司第五十四研究所 | A kind of demodulation method of satellite mobile communication system DKAB |
| CN110831147A (en) * | 2019-11-08 | 2020-02-21 | 北京邮电大学 | Carrier frequency synchronization method suitable for millimeter wave intersatellite link |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103747517B (en) | 2018-06-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102724149A (en) | Frequency offset precompensation method, random access method, equipment and system | |
| EP1279311B1 (en) | Time of arrival estimation for edge/gsm | |
| CN101626357B (en) | Carrier synchronization method of MPSK system based on maximum likelihood estimation | |
| CN112584484A (en) | Signal sending and processing method and device | |
| CN102480452B (en) | Carrier frequency synchronous circuit and method of OFDM (Orthogonal Frequency Division Multiplexing) system | |
| CN103828398A (en) | Carrying method and user device of synchronous signals | |
| CN103747517A (en) | Frequency synchronizing method and device | |
| WO2019232073A1 (en) | System and method for extracting satellite to ground link quality using satellite telemetry signal and low complexity receiver | |
| JP5219528B2 (en) | Radio receiving apparatus and radio receiving method | |
| CN113315595A (en) | Downlink initial synchronization tracking method of narrow-band Internet of things system | |
| CN102098259B (en) | Signal emission method in multi-subband orthogonal frequency division multiplexing (OFDM) system | |
| Gaspar et al. | Synchronization using a pseudo-circular preamble for generalized frequency division multiplexing in vehicular communication | |
| EP2061157B1 (en) | Method and receiver apparatus for determining a correlation value considering frequency correction | |
| CN102045286B (en) | Method and device for evaluating frequency offset, and method and device for detecting master synchronization sequences | |
| CN102833849B (en) | Positioning method and user equipment | |
| CN101404518B (en) | Frequency deviation estimation method and apparatus used for radio communication system | |
| CN113660718B (en) | Method and system for time synchronization in satellite communication | |
| CN101312378B (en) | Estimation method for time-delay spreading parameter of receiving machine and time-delay spreading parameter estimation unit | |
| CN110138414A (en) | A kind of frequency-hopping transmissions fast synchronization method of bursting suitable for satellite communication | |
| CN103676634A (en) | Time pulse synchronization method based on RDSS satellite navigation system | |
| CN102291349A (en) | Signal to noise ratio estimation method and device for orthogonal frequency division multiplexing system | |
| Ferré et al. | A dual waveform differential chirp spread spectrum transceiver for leo satellite communications | |
| CN103517286A (en) | Method for determining clock asynchronization and device thereof | |
| US6813307B1 (en) | Module channel for acquiring and tracking in a radio communication system | |
| CN103648156A (en) | Downlink signal symbol timing synchronization method and device for satellite mobile communication system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20200727 Address after: 610000 Sichuan city of Chengdu province Tianfu Zheng Xing Shun Shing Street No. 172 Patentee after: Huali Zhixin (Chengdu) integrated circuit Co., Ltd Address before: 100000, No. 18, building No. 8, hospital B, West Wang Xi Road, Haidian District, Beijing Patentee before: HWA CREATE Corp.,Ltd. |