CN1697345A - Method for synchronizing down going service code channel in CDMA system of using intelligent antenna - Google Patents
Method for synchronizing down going service code channel in CDMA system of using intelligent antenna Download PDFInfo
- Publication number
- CN1697345A CN1697345A CN 200410034767 CN200410034767A CN1697345A CN 1697345 A CN1697345 A CN 1697345A CN 200410034767 CN200410034767 CN 200410034767 CN 200410034767 A CN200410034767 A CN 200410034767A CN 1697345 A CN1697345 A CN 1697345A
- Authority
- CN
- China
- Prior art keywords
- synchronous
- code channel
- point
- data
- professional
- 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
- Mobile Radio Communication Systems (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
Abstract
Based on synchronization header, the disclosed method solves down going synchronization position primarily. Based on demodulated synchronous training sequence, using method for searching of maximal correlated power point modifies down going synchronization of service code channel so as to obtain higher synchronous accuracy, and raise SNR after system demodulation. Not need of adding training sequence, but using characteristic of signal itself, the method increases down going synchronous accuracy of system, and raises communication quality of system of service code channel in environment of multiple paths.
Description
Technical field
The present invention relates to a kind of code division multiple address communication system, relate to use the method for synchronous of downlink business code channel of the code division multi-address radio communication system (CDMA) of intelligent antenna technology or rather.
Background technology
Denomination of invention discloses a kind of method of setting up and keeping synchronous code division multiple access communication system (SCDMA) link for the 97118934.X Chinese patent of " foundation of synchronous code division multiple access communication chain and maintenance method ", comprising being the processing method to downstream signal that realizes synchronously, terminal adopted.The detection that this method relies on fully to synchronous head realizes the synchronous of downlink business code channel.Under the more sparse electromagnetic propagation environment of building, perhaps exist between base station and terminal in the application of fixed wireless access of line-of-sight propagation (LOS), downlink business code channel (code channel) method for synchronous of this SCDMA wireless communication system satisfies the requirement of voice communication substantially.But in the urban environment of building comparatively dense, ubiquity non-sight line (NLOS) and is propagated and multipath (Multipath) propagation phenomenon.For overcome that the multipath phenomenon causes to the decline of signal and interference so that cause infringements such as communication quality reduction, power system capacity reduction, in synchronous code division multiple access communication system, introduced smart antenna to significantly reduce total interference.In this case, the disclosed detection that relies on fully synchronous head of 97118934.X Chinese patent realizes that the existing defective of method for synchronous of downlink business code channel just highlights.This be because: in using the SCDMA system of smart antenna, the downlink business code channel sends after by base station intelligent antenna travel direction wave beam forming, and being requirement, synchronous head covers the non-directivity signal of whole sub-district, therefore synchronous head and downlink business code channel the space channel of process be actually different, the decline feature of the two, synchronous characteristic etc. exist difference, multipath is serious more, and its difference is big more.Therefore under multipath conditions, the method for synchronous of this downlink business code channel can cause signal to noise ratio to reduce, and the error rate improves, and communication quality descends, and cutting off rate raises.
Summary of the invention
The technical problem to be solved in the present invention provides the method for synchronous of downlink business code channel in a kind of simple and effective code division multi-address radio communication system, thereby has overcome above-mentioned defective.
Method of the present invention may further comprise the steps:
(1) in synchronous head, designs a fixing known array as synchronous training sequence;
(2) base station is to all portable terminal emission synchronous heads, and the signal measurements that has obtained through over-sampling that portable terminal will receive is carried out correlation computations with the local synchronous training sequence that produces, the data starting point A of the professional code channel of preliminary judgement;
(3) be datum mark with the data starting point A that obtains in the step (2), get n sampled point of left and right deviation, the correlation computations of sliding, ask related power and, and select power wherein and the pairing sampled point of maximum be the starting point A ' of service code track data;
(4) the service code track data starting point A ' that is tried to achieve with step (3) obtains the data result R1 of professional code channel as the data of down-going synchronous point despread traffic code channel; The service code track data starting point A that solves with step (2) obtains the data result R2 of professional code channel as the data of down-going synchronous point despread traffic code channel;
(5) signal to noise ratio of comparative result R1, R2 is selected the output of the professional code channel of the big conduct of signal to noise ratio, realizes the synchronous of professional code channel thus.
Preferably, the position of the maximum correlation peak that correlation computations solves in the step (2) is the down-going synchronous point that obtains according to synchronous head, according to the position of this down-going synchronous point and the signaling format of SCDMA system, and the data starting point A of the professional code channel of preliminary judgement.
Preferably, after obtaining n sampled point in the step (3), utilize the principle of associated window, in the window of 2n+1, slide relevant with local with the long orthogonal spreading sequence of the m2 of spreading rate generation for receiving m1 the signal measurements that obtains with the spreading rate sampling.
As from the foregoing, the present invention at first solves the down-going synchronous position according to synchronous head.Because the synchronous training sequence downlink is different with smart antenna emission space link, so under the multipath serious situation, the data original position of determined professional code channel is inaccurate.And on the other hand, the professional code channel signal of SCDMA has following characteristic: when customer service code channel information sequence alignment (promptly synchronous) that this locality customer service code channel orthogonal spreading sequence that produces and the base station that receives issue, will obtain the related power of maximum.The present invention is just on the basis of demodulation synchronous training sequence, utilize the speciality of the professional code channel signal self of SCDMA, revise for the sync bit that obtains, thereby utilized the down-going synchronous of the professional code channel of method correction by seeking the maximal correlation power points to obtain higher synchronous accuracy, improved the signal to noise ratio after system's demodulation.Therefore, method provided by the present invention does not need to increase training sequence, but utilizes the characteristic of signal itself, has improved the synchronous accuracy of system descending, has improved the communication quality of system's professional code channel in multi-path environment greatly.
Description of drawings
Below in conjunction with accompanying drawing the specific embodiment of the present invention is described in further detail.In the accompanying drawing:
Fig. 1 is the schematic diagram of downlink business code channel and synchronous head different transmission path in the antenna system of time division duplex (TDD) code division multiple access (CDMA);
Fig. 2 is the process chart of professional code channel down-going synchronous.
Embodiment
Fig. 1 has illustrated the antenna system downlink business code channel and the synchronous head different transmission path of time division duplex (TDD) code division multiple access (CDMA), wherein dotted line represent synchronous head emission the path of process, solid line is the propagation path of a certain subscriber signal of smart antenna emission in the sub-district.There is evident difference in the path that can obviously see synchronous head and user experience, and the difference in this path directly causes synchronous head that the user receives and the time delay between the subscriber signal.The present invention is exactly the influence that maximum this feature of related power is eliminated this delay inequality when utilizing the subscriber signal of CDMA and the local respective orthogonal frequency expansion sequence that produces synchronous, the elevator system performance.
The down link synchronisation method of professional code channel in the antenna system of the specific embodiment of the invention is described below in conjunction with Fig. 2.
At first, in synchronous head SYNC, design a fixing known array DOWN_SYNC as synchronous training sequence.The main purpose of synchronous training sequence is the content that receiving terminal has been known synchronous training sequence, can obtain synchronous timing information according to the situation that receives synchronous training sequence.Known array DOWN_SYNC for example can be the sequence of complete " 1 " or " 0 " of one section regular length.Wherein, synchronous training sequence can be chosen the sign indicating number sequence of known fixed in the product of pseudo random sequence and walsh code.In addition, only contain synchronous training sequence in the synchronous head.
Secondly, base station BS is to all portable terminal emission synchronous heads, the signal measurements that portable terminal will be obtains through over-sampling and the local synchronous training sequence that produces (this synchronous training sequence and base station down necessary identical) carry out correlation computations, the position of the maximum correlation peak that solves is the down-going synchronous point that obtains according to synchronous head, according to the position of this down-going synchronous point and the signaling format of SCDMA system, the data starting point A of the professional code channel of preliminary judgement;
Next step is a datum mark with the A point that obtains in the step (2), gets n sampled point of left and right deviation, and the value of n is scattered decision according to the multidiameter delay in the wireless channel, and is different according to the time delay stroll of different communication environments multipaths, needs the different n value of definition.Can determine the n value according to following formula
The over-sampling rate * multipath maximal phase of n=terminal to the width of delay inequality/chip wherein, over-sampling rate be spreading rate n doubly, n is the integer more than or equal to 2.
Utilize the principle of associated window, in the window of 2n+1 for the m1 that a receives sampled point.Wherein, m1=2n+1+m2, m2 are the length of synchronous training sequence.M1 sampled point is to get n sampled point according to down-going synchronous point left for datum mark, gets n+m2 sampled point to the right.It is relevant that m1 sampled point and the local synchronous training sequence that produces (orthogonal spreading sequence that m2 is long) slide, ask related power and, select power wherein and the pairing sampled point of maximum be the starting point A ' of service code track data;
Next step, the service code track data starting point A ' that is tried to achieve with step (3) obtains service code track data R1 as a result as the data of down-going synchronous point despread traffic code channel; The synchronous points that solves with step (2) obtains service code track data R2 as a result as the data of down-going synchronous point despread traffic code channel;
At last, the signal to noise ratio snr of comparative result R1, R2 is selected the output of the professional code channel of the big conduct of signal to noise ratio, realizes the more accurate synchronous of professional code channel thus.
Claims (6)
1. the method for synchronous of the downlink business code channel in the code division multiple access system that uses smart antenna, it is characterized in that: it may further comprise the steps:
(1) in synchronous head, designs a fixing known array as synchronous training sequence;
(2) base station is to all portable terminal emission synchronous heads, and the signal measurements that has obtained through over-sampling that portable terminal will receive is carried out correlation computations with the local synchronous training sequence that produces, the data starting point A of the professional code channel of preliminary judgement;
(3) be datum mark with the data starting point A that obtains in the step (2), get n sampled point of left and right deviation, the correlation computations of sliding, ask related power and, and select power wherein and the pairing sampled point of maximum be the starting point A ' of service code track data;
(4) the service code track data starting point A ' that is tried to achieve with step (3) obtains the data result R1 of professional code channel as the data of down-going synchronous point despread traffic code channel; The data starting point A of the professional code channel that solves with step (2) obtains the data result R2 of professional code channel as the data of down-going synchronous point despread traffic code channel;
(5) signal to noise ratio of comparative result R1, R2 is selected the output of the professional code channel of the big conduct of signal to noise ratio, realizes the synchronous of professional code channel thus.
2. method for synchronous as claimed in claim 1 is characterized in that: the described known array of step (1) is the sign indicating number sequence of the known fixed chosen in the product of pseudo random sequence and walsh code.
3. method for synchronous as claimed in claim 1, it is characterized in that: the position of the maximum correlation peak that correlation computations is solved in the step (2) is the down-going synchronous point that obtains according to synchronous head, according to the position of this down-going synchronous point and the signaling format of SCDMA system, the data starting point A of the professional code channel of preliminary judgement.
4. method for synchronous as claimed in claim 1, it is characterized in that: after obtaining n sampled point in the step (3), utilize the principle of associated window, in the window of 2n+1, slide relevant with local with the long orthogonal spreading sequence of the m2 of spreading rate generation for receiving m1 the signal measurements that obtains with the spreading rate sampling.
5. method for synchronous as claimed in claim 4 is characterized in that: the value of the described n of step (3) can be determined according to following formula:
The over-sampling rate of n=terminal * multipath maximal phase is to the width of delay inequality/chip
6. method for synchronous as claimed in claim 5, it is characterized in that: in the step (3), m1=2n+1+m2, m2 are the length of synchronous training sequence, m1 sampled point is to get n sampled point according to down-going synchronous point left for datum mark, gets to the right that n+m2 sampled point obtain.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100347672A CN100361423C (en) | 2004-05-12 | 2004-05-12 | Method for synchronizing down going service code channel in CDMA system of using intelligent antenna |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100347672A CN100361423C (en) | 2004-05-12 | 2004-05-12 | Method for synchronizing down going service code channel in CDMA system of using intelligent antenna |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1697345A true CN1697345A (en) | 2005-11-16 |
| CN100361423C CN100361423C (en) | 2008-01-09 |
Family
ID=35349895
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100347672A Expired - Fee Related CN100361423C (en) | 2004-05-12 | 2004-05-12 | Method for synchronizing down going service code channel in CDMA system of using intelligent antenna |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100361423C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012106866A1 (en) * | 2011-07-05 | 2012-08-16 | 华为技术有限公司 | Signal demodulation method and receiving device |
| CN101499845B (en) * | 2008-01-29 | 2013-03-27 | 电信科学技术研究院 | Uplink synchronous detection method and apparatus for TD-SCDMA system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030013479A1 (en) * | 2001-07-13 | 2003-01-16 | Dan Vassilovski | Mobile communication device preferential system selection |
| CN100461656C (en) * | 2001-12-20 | 2009-02-11 | 北京六合万通微电子技术有限公司 | Synchronous signal detecting circuit device and detecting method of said device detecting synchronous signal |
| EP1347611A1 (en) * | 2002-03-20 | 2003-09-24 | Siemens Information and Communication Networks S.p.A. | Data aided frequency synchronisation |
| CN1263248C (en) * | 2002-12-31 | 2006-07-05 | 北京信威通信技术股份有限公司 | Multiple point demodulation and method for regulating synchronous CDMA system as quasi-synchronization each frame for |
-
2004
- 2004-05-12 CN CNB2004100347672A patent/CN100361423C/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101499845B (en) * | 2008-01-29 | 2013-03-27 | 电信科学技术研究院 | Uplink synchronous detection method and apparatus for TD-SCDMA system |
| WO2012106866A1 (en) * | 2011-07-05 | 2012-08-16 | 华为技术有限公司 | Signal demodulation method and receiving device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100361423C (en) | 2008-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1135725C (en) | Search window delay tracking in code division multiple access communication systems | |
| CA2293305C (en) | Mobile station synchronization within a spread spectrum communications system | |
| JP4318963B2 (en) | Pilot signal for synchronization and / or channel estimation | |
| US8300574B2 (en) | Method of uplink synchronization establishment based on the united transmission technology | |
| CN1146156C (en) | Forming method of training sequence in channel evaluation | |
| CN1350379A (en) | Method of raising TD-CDMA system channel estimation accuracy | |
| CN1210987C (en) | Method on cell site selection in cellular system with interference free window | |
| CN100361423C (en) | Method for synchronizing down going service code channel in CDMA system of using intelligent antenna | |
| FI113921B (en) | Receiver, Receiving Method, Computer Program, and Computer Memory | |
| EP1699154A1 (en) | Multi-path search method of code-division multiple-access system | |
| CN100534000C (en) | Matched filter, judging device and search method | |
| CN1327720C (en) | Method for testing modulated phase cluster of sync code in time division synchronization CDMA access system | |
| US8238409B2 (en) | Managing tap positions in a digital delay line | |
| CN1499860A (en) | Initial synchronous search in mobile communication system | |
| CN109217968B (en) | Short-distance wireless network based on phase shift keying technology and adopting CDMA technology | |
| CN1980086B (en) | Method for random accessing message demodulation | |
| RU2787776C1 (en) | Method for quasi-synchronous multiple access with code separation based on clock frequency synchronization conditions | |
| KR100914404B1 (en) | Signal Quality Measuring Apparatus and Method for WCDMA System | |
| KR20120123176A (en) | Timing synchronization method and apparatus in wireless communications system | |
| CN101164246B (en) | Method for selecting delay values for a rake receiver and the rake receiver | |
| EP1251642B1 (en) | A CDMA mobile station with power saving using adaptive correlation window in path search | |
| JP2004289717A (en) | Random access control method, base station, and terminal device | |
| JP2000349703A (en) | Pilot signal for synchronization and/or channel estimation | |
| EP1672808B1 (en) | Selecting peak delay values for a RAKE receiver | |
| CN1493124A (en) | Method and device for capturing of down synchronization in CDMA 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 | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| PP01 | Preservation of patent right |
Effective date of registration: 20191121 Granted publication date: 20080109 |
|
| PP01 | Preservation of patent right | ||
| PD01 | Discharge of preservation of patent |
Date of cancellation: 20200710 Granted publication date: 20080109 |
|
| PD01 | Discharge of preservation of patent | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080109 Termination date: 20200512 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |