CN101114877B - Enhanced synchronous channel transmitting method - Google Patents
Enhanced synchronous channel transmitting method Download PDFInfo
- Publication number
- CN101114877B CN101114877B CN2007101302668A CN200710130266A CN101114877B CN 101114877 B CN101114877 B CN 101114877B CN 2007101302668 A CN2007101302668 A CN 2007101302668A CN 200710130266 A CN200710130266 A CN 200710130266A CN 101114877 B CN101114877 B CN 101114877B
- Authority
- CN
- China
- Prior art keywords
- sch
- time
- sch signal
- sends
- signal
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Mobile Radio Communication Systems (AREA)
Abstract
A reinforced synchronous channel sending method is applied to a time-multiplexed duplex system, which is based on the orthogonal frequency division multiplexing technique with a primary synchronous channel P-SCH sent on a downstream time slot DwPTS and an auxiliary synchronous channel S-SCH sent on the last orthogonal frequency division multiplexing OFDM signal of the TS0 time slot. The method is characterized in that an extended cyclic prefix of P-SCH is sent in the part near the P-SCH in the time slot interval between the S-SCH and P-SCH.
Description
Technical field
The present invention relates to digital communicating field, particularly relate to Cell searching technology based on the tdd systems of OFDM (OFDM) technology, specifically, relate to synchronizing channel in the OFDM tdd systems (Synchronization Channel, sending method SCH).
Background technology
When mobile platform started or lose network when service, need come capture systems by initial acquisition process, capture systems means and identifies the sub-district that travelling carriage is wanted standby and demodulated the system information in the broadcast channel.Acquisition procedure is also referred to as cell search process.Cell searching mainly is time and the Frequency Synchronization that obtains with Target cell, also obtains target cell identification number and some essential informations simultaneously.Cell search process mainly is based on synchronizing channel, and (Synchronization Channel SCH) carries out, and travelling carriage has obtained time synchronized with Target cell according to synchronizing channel, and cell identification number or cell identification group number information.In the time can only obtaining cell identification group number information by synchronizing channel, other information that complete cell identification information is relevant with sub-district/system then can pass through broadcast channel (Broadcast Channel, BCH) and pilot tone obtain.
As a rule, cell search process is the process of a classification, therefore corresponding synchronizing channel (SCH) be divided into primary synchronization channel (Primary SCH, P-SCH) and auxiliary synchronization channel (SecondarySCH, S-SCH).P-SCH is used for realizing slot timing and frequency calibration, and S-SCH is mainly used to achieve frame regularly and the detection of cell identification number or cell identification group number and some sub-district/system related informations.
Accompanying drawing 1 is a kind of frame structure schematic diagram of the tdd systems based on orthogonal frequency division multiplexi.In the diagram, the radio frames of 10ms comprises two isometric subframes, and the length of each subframe is 5ms.Each subframe comprises 7 general time slots and 3 special time slots again: DwPTS time slot, GP time slot and UpPTS time slot.Wherein, the DwPTS time slot is a descending time slot, and descending master sync signal P-SCH is fixed on this time slot and sends, and its time length is 75us.The GP time slot is TDD (time division duplex) system up-downgoing protection time slot, and time span also is 75us.The UpPTS time slot is an ascending time slot.Each general time slots length is 0.675ms.
For TS0, it comprises 8 or 9 OFDM symbols and a time interval, and wherein, the common pilot signal that is used for channel estimating is positioned at first and third from the bottom OFDM symbol.When it comprised 8 OFDM (OFDM) symbol, each OFDM symbol was a long loop prefix, and wherein long loop prefix length is 16.67us, and data division length is 66.67us, and slot time length is 8.33us.When it comprised 9 OFDM symbols, each OFDM symbol was short Cyclic Prefix, and its short-and-medium circulating prefix-length is 7.29us, and data division length is 66.67us, and slot time length is 9.38us, usually, does not send any data in the slot time.In addition, represent that to upward arrow this time slot is an ascending time slot, arrow represents that this time slot is a descending time slot downwards.Except TS0 is fixed as descending time slot, TS1 is fixed as outside the ascending time slot, and other time slot can be assigned as up or descending time slot flexibly according to service needed.
Accompanying drawing 2 is the sending method of existing synchronizing signal, and from figure as can be seen, descending master sync signal P-SCH is fixed on the DwPTS time slot and sends, and auxiliary synchronous signal S-SCH sends on last OFDM symbol of TS0.Therefore, between last OFDM symbol of time slot DwPTS and TS0, have a slot time (Timeslot Interval, TI), this slot time will be along with the difference of the circulating prefix-length that the TS0 time slot adopted difference.When TS0 comprised 8 OFDM symbols, each OFDM symbol was a long loop prefix, and wherein long loop prefix length is 16.67us, and data division length is 66.67us, and corresponding slot time length is 8.33us; When TS0 comprised 9 OFDM symbols, each OFMD symbol was short Cyclic Prefix, and its short-and-medium circulating prefix-length is 7.29us, and data division length is 66.67us, and corresponding slot time length is 9.38us.
Therefore, adopt existing synchronization channel transmission method, travelling carriage is being received after the P-SCH signal finishes slot timing and detect, and can not directly obtain the timing information of S-SCH signal, and travelling carriage must carry out blind Detecting to S-SCH.This has increased the time of Cell searching and the implementation complexity of travelling carriage undoubtedly.
On the other hand, from the discussion of front as can be known, because the DwPTS time slot has only 75us, the data division 66.67us of deduction OFDM symbol, the circulating prefix-length of primary synchronization channel P-SCH signal is 8.33us. to the maximum and auxiliary synchronization channel S-SCH signal can adopt long loop prefix (16.67us) or short Cyclic Prefix (7.29us) to send according to channel condition.P-SCH and S-CH signal cycle prefix length do not match, directly cause the detection performance of P-SCH and S-SCH signal not match, this Cell searching for travelling carriage is very unfavorable, for instance: under the bigger environment of channel delay spread, the base station must send the S-SCH signal with long loop prefix OFDM symbol just might be moved the platform detection, but since the P-SCH signal only with utilize short Cyclic Prefix (8.33us＜＜16.67us) send, its consequence is no matter how the base station sends the S-SCH signal, because the P-SCH signal can't correctly detect, the S-SCH signal also can't correctly detect.
Therefore, at above problem, the sending method of improving existing synchronizing channel is very important.
Summary of the invention
Technical problem to be solved by this invention is to provide a kind of sending method based on synchronizing channel in the tdd systems of orthogonal frequency division multiplexi, performance and reduction equipment implementing complexity to improve Cell searching also help P-SCH and the unmatched problem of S-SCH signal detection performance of solving simultaneously.The present invention is applicable to that primary synchronization channel P-SCH is fixed on the DwPTS time slot and sends that the tdd systems that auxiliary synchronization channel S-SCH sends specifically describes as follows on last OFDM symbol of TS0:
A kind of synchronous channel signal sending method of enhancing, be applied to tdd systems based on orthogonal frequency division multiplexi, primary synchronization channel P-SCH signal sends on descending time slot DwPTS, auxiliary synchronization channel S-SCH signal sends in the transmitting time of last orthogonal frequency division multiplex OFDM symbol of TS0 time slot, described TS0 comprises time and time interval that sends 8 or 9 OFDM symbols, wherein, the common pilot signal that is used for channel estimating is positioned at first and third from the bottom OFDM symbol, it is characterized in that: the extended cyclic prefix of the time portion transmission P-SCH signal of the close P-SCH of transmission signal on the slot time that sends between S-SCH signal and the transmission P-SCH signal.
The time span of described extended cyclic prefix is a constant C under the different circulating prefix structure of TS0, is used to send the cyclic suffix of described S-SCH signal on the slot time between described transmission S-SCH signal and the transmission P-SCH signal except that the part of extended cyclic prefix the time that sends the P-SCH signal.
Described transmission S-SCH signal and the slot time that sends between the P-SCH signal are divided into part 1, part 2, part 3, three partial continuous distribute, part 1 is near the time that sends the S-SCH signal, part 2 is between part 1 and the part 3, part 3 is near the time that sends the P-SCH signal, be a constant C wherein in the different circulating prefix structure lower part 2 of TS0 and the length sum of part 3, part 1 sends the cyclic suffix of described S-SCH signal, and part 3 sends the extended cyclic prefix of described P-SCH signal.
When described TS0 comprised 8 OFDM symbols, described transmission S-SCH signal and the slot time that sends between the P-SCH signal were L
LCP, this slot time all is used to send the extended cyclic prefix of P-SCH signal, and when described TS0 comprised 9 OFDM symbols, described transmission S-SCH signal and the slot time that sends between the P-SCH signal were L
SCP, this slot time is L near the length that sends the S-SCH signal time
SCP-L
LCPPart is used for sending the cyclic suffix of S-SCH signal, is L near the length that sends the P-SCH signal time
LCPPart be used to send the extended cyclic prefix of P-SCH signal.
The signaling method that provides of the present invention is provided, and travelling carriage can directly extract the S-SCH signal synchronously, avoid the step of cyclic prefix length detection, both reduce and handled time-delay, reduce implementation complexity again utilizing P-SCH to finish slot timing.On the other hand, the part among the time interval TI is used to send the extended cyclic prefix of P-SCH, this will help improving P-SCH in channel time delay expansion than the performance under the overall situation.
Description of drawings
Accompanying drawing 1 is a structure of time slot schematic diagram in the existing TDD system;
Accompanying drawing 2 is sending method schematic diagrames of existing synchronizing channel;
Accompanying drawing 3 is transmission schematic diagrames of the embodiment of the invention one synchronous channel;
Accompanying drawing 4 is transmission schematic diagrames of the embodiment of the invention two synchronizing channels.
Embodiment
In common TDD system, be separated with two effects between time slots: 1. be used for the up-downgoing switch protecting; 2. avoid the interference between time slot.In the TDD system based on the OFDM technology, the back of TS0 is the DwPTS time slot, and the two all is a descending time slot, and therefore, the slot time of TS0 is not used in the up-downgoing switch protecting and just is used to avoid the interference of the data of TS0 to the data of DwPTS.Therefore, this idle resource of the time interval TI of reasonable use TS0 is feasible with the Cell searching performance of improving synchronizing channel.
Principal character of the present invention is: the time interval between S-SCH and the P-SCH is divided into two parts, and wherein the part near S-SCH is called part 1, and the part of close P-SCH is called part 2.Part 1 is used for sending the cyclic suffix of S-SCH symbol, and part 2 is used for sending the extended cyclic prefix of P-SCH symbol, and the time that requires part 2 to continue is a constant that does not change with the employed circulating prefix-length of TS0.The length of supposing the TS0 time corresponding interval T I of short Cyclic Prefix of employing and long loop prefix is respectively L
SCP, L
LCP(L here,
SCP＞L
LCP), in order to guarantee under two kinds of circulating prefix structure that the time that part 2 continues is a constant that does not rely on the employed circulating prefix-length variation of TS0, the times that part 1 and part 2 continue can be chosen according to following mode so:
(1) when TS0 adopts the weak point Cyclic Prefix, the time that part 1 continues is L
SCP-L
LCP+ C is used to send the cyclic suffix of S-SCH, and the times that part 2 continues are L
LCP-C is used to send the extended cyclic prefix of P-SCH;
(2) when TS0 adopts long loop prefix, the time that part 1 continues is C, is used to send the cyclic suffix of S-SCH, and the time that part 2 continues is L
LCP-C is used to send the extended cyclic prefix of P-SCH;
Wherein, C is a constant, and its span is: 0≤C≤L
LCP
In another embodiment of the present invention, the time interval between S-SCH and the P-SCH is divided into three parts, and wherein the part near S-SCH is called part 1, and the part of close P-SCH is called part 3, is part 2 between part 1 and the part 3.Part 1 is used for sending the cyclic suffix of S-SCH symbol, and part 3 is used for sending the extended cyclic prefix of P-SCH symbol, and to require part 2 and part 3 lasting time of adding up be a constant that does not change with the employed circulating prefix-length of TS0.
In E-UTRA TDD system, the duration of short Cyclic Prefix is 7.29us, and the time interval of corresponding TS0 is 9.38us, and the duration of long loop prefix is 16.67us, and the time interval of corresponding TS0 is 8.33us.As previously mentioned, the duration of DwPTS time slot is 75us, deduction OFDM symbol data division 66.67us, the circulating prefix-length of primary synchronization channel P-SCH signal is 8.33us to the maximum.As a special case of the present invention, when C=0, the time that is used to send the P-SCH extended cyclic prefix is L
LCP, just 8.33us adds original 8.33us, just is equivalent to the length 16.67us of long loop prefix, therefore, C=0 can be used as the best value of C, that is:
(1) when TS0 adopts the weak point Cyclic Prefix, the time that part 1 continues is L
SCP-L
LCP, being used to send the cyclic suffix of S-SCH, the times that part 2 continues are L
LCP, be used to send the extended cyclic prefix of P-SCH;
(2) when TS0 adopts long loop prefix, the time that part 1 continues is 0, and the time that promptly is used to send the cyclic suffix of S-SCH is 0 (not sending the cyclic suffix of S-SCH in other words), and the times that part 2 continues are L
LCP, be used to send the extended cyclic prefix (slot time all be used for sending extended cyclic prefix) of P-SCH.
Accompanying drawing 3 has provided the schematic diagram of the sending method of the embodiment of the invention one synchronous channel.For the TS0 that adopts short Cyclic Prefix, the duration of part 1 is L
SCP-L
LCP+ C is used to send the cyclic suffix of S-SCH signal; The duration of part 2 is L
LCP-C is used to send the extended cyclic prefix of P-SCH; And for the TS0 that adopts long loop prefix, the duration of part 1 is C, is used to send the cyclic suffix of S-SCH signal, and the duration of part 2 is L
LCP-C is used to send the extended cyclic prefix of P-SCH.Utilize the sending method of above-mentioned synchronizing channel, travelling carriage utilizes P-SCH to finish slot timing can directly extract the S-SCH signal synchronously, has avoided the step of cyclic prefix length detection, has both reduced and has handled time-delay, has reduced implementation complexity again.Simultaneously, the S-SCH signal sends the (slot time of P-SCH and S-SCH in the position near the P-SCH signal, maximum is no more than 9.38us), compare with public guide frequency, the P-SCH signal has higher energy and density, thereby can provide better channel estimating, and then guarantee that the S-SCH signal has better demodulation performance for S-SCH.On the other hand, because the L among the time interval TI
LCP-C has been equivalent to increase the Cyclic Prefix of P-SCH partly as the extended cyclic prefix of P-SCH symbol, and this helps improving the detection performance of P-SCH signal under the bigger environment of channel time delay expansion.
Accompanying drawing 4 has provided another and has comprised the transmission schematic diagram of synchronizing channel of the present invention.In this schematic diagram, corresponding to the special case of C=0.For the TS0 that adopts short Cyclic Prefix, the duration of part 1 is L
SCP-L
LCP, being used to send the cyclic suffix of S-SCH signal, the duration of part 2 is L
LCP, be used to send the extended cyclic prefix of P-SCH; For the TS0 that adopts long loop prefix, slot time is used for sending the extended cyclic prefix of P-SCH signal all, and the duration is L
LCPLike this, under two kinds of circulating prefix structure, the time that is used to send the P-SCH extended cyclic prefix all is L
LCPCompare with accompanying drawing 3, in the sending method that accompanying drawing 4 provides, the part of extended cyclic prefix that is used to send P-SCH among the time interval TI is the longest, and 8.33us is arranged, this moment equivalent Cyclic Prefix time of P-SCH is 16.67us, the situation that is equivalent to long loop prefix, at this moment, the ability of P-SCH opposing selectivity of channel frequency decline is the strongest, thereby, the sending method that accompanying drawing 4 provides helps improving P-SCH most and S-SCH detects not matching of performance, thereby improves the overall performance of Cell searching.
Claims (4)
1. the synchronous channel signal sending method of an enhancing, be applied to tdd systems based on orthogonal frequency division multiplexi, primary synchronization channel P-SCH signal sends on descending time slot DwPTS, auxiliary synchronization channel S-SCH signal sends in the transmitting time of last orthogonal frequency division multiplex OFDM symbol of TS0 time slot, described TS0 comprises time and time interval that sends 8 or 9 OFDM symbols, wherein, the common pilot signal that is used for channel estimating is positioned at first and third from the bottom OFDM symbol, it is characterized in that: the extended cyclic prefix of the time portion transmission P-SCH signal of the close P-SCH of transmission signal on the slot time that sends between S-SCH signal and the transmission P-SCH signal.
2. the method for claim 1, it is characterized in that: the time span of described extended cyclic prefix is a constant C under the different circulating prefix structure of TS0, is used to send the cyclic suffix of described S-SCH signal on the slot time between described transmission S-SCH signal and the transmission P-SCH signal except that the part of extended cyclic prefix the time that sends the P-SCH signal.
3. the method for claim 1, it is characterized in that: described transmission S-SCH signal and the slot time that sends between the P-SCH signal are divided into part 1, part 2, part 3, three partial continuous distribute, part 1 is near the time that sends the S-SCH signal, part 2 is between part 1 and the part 3, part 3 is near the time that sends the P-SCH signal, be a constant C wherein in the different circulating prefix structure lower part 2 of TS0 and the length sum of part 3, part 1 sends the cyclic suffix of described S-SCH signal, and part 3 sends the extended cyclic prefix of described P-SCH signal.
4. method as claimed in claim 2 is characterized in that: when described TS0 comprised 8 OFDM symbols, described transmission S-SCH signal and the slot time that sends between the P-SCH signal were L
LCP, this slot time all is used to send the extended cyclic prefix of P-SCH signal, and when described TS0 comprised 9 OFDM symbols, described transmission S-SCH signal and the slot time that sends between the P-SCH signal were L
SCP, this slot time is L near the length that sends the S-SCH signal time
SCP-L
LCPPart is used for sending the cyclic suffix of S-SCH signal, is L near the length that sends the P-SCH signal time
LCPPart be used to send the extended cyclic prefix of P-SCH signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007101302668A CN101114877B (en) | 2007-03-12 | 2007-07-17 | Enhanced synchronous channel transmitting method |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200710086819.4 | 2007-03-12 | ||
| CN200710086819 | 2007-03-12 | ||
| CN2007101302668A CN101114877B (en) | 2007-03-12 | 2007-07-17 | Enhanced synchronous channel transmitting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101114877A CN101114877A (en) | 2008-01-30 |
| CN101114877B true CN101114877B (en) | 2010-12-08 |
Family
ID=39023025
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007101302668A Expired - Fee Related CN101114877B (en) | 2007-03-12 | 2007-07-17 | Enhanced synchronous channel transmitting method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101114877B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101499989B (en) * | 2008-02-01 | 2012-04-18 | 电信科学技术研究院 | Method for detecting cyclic prefix length in time division duplex system |
| CN101499963B (en) * | 2008-02-03 | 2011-07-20 | 大唐移动通信设备有限公司 | Method and apparatus for downlink transmission |
| CN101599937B (en) * | 2008-06-02 | 2013-01-09 | 电信科学技术研究院 | Method and device for transmitting physical multicasting channel in special time slot |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1164733A1 (en) * | 2000-01-24 | 2001-12-19 | NTT DoCoMo, Inc. | Channel constructing method and base station using the method |
| CN1464654A (en) * | 2002-06-12 | 2003-12-31 | 电子科技大学 | Method for controlling bit after frame end insertion in OFDM communication system |
| CN1499860A (en) * | 2002-11-02 | 2004-05-26 | Lg������ʽ���� | Initial synchronous search in mobile communication system |
| CN1553586A (en) * | 2003-12-19 | 2004-12-08 | 大唐移动通信设备有限公司 | Descending synchronous calibrating method and apparatus for TD-SCDMA system |
| CN1694380A (en) * | 2005-06-09 | 2005-11-09 | 中兴通讯股份有限公司 | Configuration method of cell code source in time-division synchronous CDMA system group network |
-
2007
- 2007-07-17 CN CN2007101302668A patent/CN101114877B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1164733A1 (en) * | 2000-01-24 | 2001-12-19 | NTT DoCoMo, Inc. | Channel constructing method and base station using the method |
| CN1464654A (en) * | 2002-06-12 | 2003-12-31 | 电子科技大学 | Method for controlling bit after frame end insertion in OFDM communication system |
| CN1499860A (en) * | 2002-11-02 | 2004-05-26 | Lg������ʽ���� | Initial synchronous search in mobile communication system |
| CN1553586A (en) * | 2003-12-19 | 2004-12-08 | 大唐移动通信设备有限公司 | Descending synchronous calibrating method and apparatus for TD-SCDMA system |
| CN1694380A (en) * | 2005-06-09 | 2005-11-09 | 中兴通讯股份有限公司 | Configuration method of cell code source in time-division synchronous CDMA system group network |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101114877A (en) | 2008-01-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100502282C (en) | Transmission method of synchronization signal of time-division duplex system | |
| CN101719890B (en) | District searching method and d device applied to long-period evolution system | |
| CN100556195C (en) | The detection of time division duplexing system circulation prefix types and cell initial search method | |
| CN101292461B (en) | Apparatus, method and computer program product providing initial cell acquisition and pilot sequence detection | |
| CN101473620B (en) | Method and apparatus for using the synchronization channel to obtain measurements of neighboring cells in an OFDM communications system | |
| CN101640661B (en) | Method and system for processing communication signal | |
| CN105828349A (en) | Far-end interference detection method and far-end interference detection device based on TD-LTE system | |
| WO2003034642A2 (en) | Synchronisation in multicarrier cdma systems | |
| BRPI0708790A2 (en) | Methods and Equipment for Generating Sending Frame and Cell Searching in Computer-Station Mobile Communication Station and Media Readable | |
| KR100965663B1 (en) | Method and apparatus for transmitting/receiving downlink synchronization channel in cellular communication systems | |
| CN101527595A (en) | Frame structure of time division duplex system and method for sending synchronous signals | |
| US20100061322A1 (en) | Method for allocating code to cells and planning cells in ofdm cellular system | |
| CN102271384B (en) | Primary cell searching method for long term evolution (LTE) system | |
| CN101114877B (en) | Enhanced synchronous channel transmitting method | |
| CN103369665A (en) | TD-LTE relay system and synchronizing signal extraction method and device thereof | |
| CN101175058B (en) | Synchronous channel transmission method of TDD system | |
| CN102238721A (en) | Terminal synchronous timing control method and device | |
| CN107734633A (en) | A kind of method and device of synchronous signal transmission | |
| CN101499989B (en) | Method for detecting cyclic prefix length in time division duplex system | |
| CN101197804B (en) | Synchronous processing method and system | |
| CN101399587A (en) | Base station transmission method and device in communication system | |
| CN101114874B (en) | Synchronous signal transmitting method of TDD system | |
| CN102547967A (en) | Method, system and user device to realize synchronization through time division duplex long-term evolution system | |
| CN103988475A (en) | Carrier frequency offset estimation method and device | |
| CN101325447B (en) | Method for transmitting synchronous signal |
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 | ||
| 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: 20101208 Termination date: 20190717 |