CN101222467B - Leading transmission method of orthogonal frequency division multiplexing system - Google Patents
Leading transmission method of orthogonal frequency division multiplexing system Download PDFInfo
- Publication number
- CN101222467B CN101222467B CN2008100042850A CN200810004285A CN101222467B CN 101222467 B CN101222467 B CN 101222467B CN 2008100042850 A CN2008100042850 A CN 2008100042850A CN 200810004285 A CN200810004285 A CN 200810004285A CN 101222467 B CN101222467 B CN 101222467B
- Authority
- CN
- China
- Prior art keywords
- leading symbol
- leading
- symbol
- information
- lead code
- 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
The invention discloses a preamble sending method for an orthogonal frequency division multiplexing system, which comprises the following steps: Step S102, a message which needs to be sent to a terminal side is confirmed; Step S104, a first preamble symbol is confirmed according to the message; and Step S106, a base station side sends the first preamble symbol and a second preamble symbol to the terminal side. With the method of the invention, the receiving end greatly reduces the times of the search and obtains more information at the same time.
Description
Technical field
The present invention relates to digital communicating field, relate in particular to the leading transmission method of a kind of OFDM (orthogonal frequency division multiplex is called for short OFDM) system.
Background technology
As a kind of multi-carrier transmission pattern, OFDM is converted to one group of low-speed parallel data flow transmitted by the data flow with one group of high speed serial transmission makes system reduce greatly the susceptibility of multidiameter fading channel frequency selectivity.In addition, the introducing of Cyclic Prefix has further strengthened the anti-intersymbol interference of the system ability of (Inter-symbol Interference is called for short ISI) again.In addition bandwidth availability ratio height, realize that characteristics such as simple make OFDM more and more wider in the application of wireless communication field.For example, digital broadcasting (DAB) and Digital Television (DVB) that european telecommunications standards institute ETSI formulates have all adopted the wireless transmission standards of OFDM technology as air interface, and WLAN standard IEEE802.11 and wireless metropolitan area network standard IEEE80.16 have also adopted the OFDM technology in addition.
IEEE802.16e has adopted the OFDM technology.According to the IEEE802.16e standard: leading (preamble) sends on the whole bandwidth of first symbol of down link, and the Segment and the IDCell information of base station only is provided.This agreement has stipulated to identify with preamble the beginning of a frame, preamble accounts for a symbol in time, be made of subcarrier on frequency domain, 114 kinds of specific pseudo random sequences (PN sequence) are modulated on the subcarrier with the BPSK method, and every the PN sequence of a bit of 3 subcarrier-modulated.Particularly each bandwidth all has 114 lead codes, and bandwidth difference, the length of lead code are also different.
Therefore, terminal for bandwidth, the information such as Segment, IDCell that obtain system, needs long search time in the down-going synchronous process, and needs very large amount of calculation.
Summary of the invention
Technical problem to be solved by this invention is exactly to solve existing lead code to design to long problem search time that down-going synchronous is brought, provide a kind of ofdm system new leading method for designing, the leading information that can provide has been provided, has not influenced again simultaneously by the terminal that has the IEEE802.16e standard production now leading reception.
According to embodiments of the invention, a kind of leading transmission method of ofdm system is provided, this method comprises following processing: step S102, determines to send to the information of end side; Step S104 determines first leading symbol according to information; And step S106, base station side sends to end side with first leading symbol and second leading symbol.
Wherein, first leading symbol and second leading symbol account for a symbol in time, be made of subcarrier on frequency domain, second leading symbol existed before definite first leading symbol, and did not change the structure and the position of second leading symbol after determining first leading symbol.
Preferably, before sending first leading symbol and second leading symbol, the lead code of second leading symbol is divided into groups.
The position of first leading symbol is before or after second leading symbol, and the position of first leading symbol and second leading symbol is continuous or discontinuous.
Information is one or more in the grouping information of lead code of system bandwidth, second leading symbol and the number of transmit antennas.
In the frequency domain structure of first leading symbol, its lead code is positioned on the part bandwidth or whole bandwidth of system.
In the frequency domain of first leading symbol structure, its lead code equally spaced be mapped on the subcarrier or Continuous Mappings to subcarrier.
The lead code relevant with first leading symbol has auto-correlation coefficient that is tending towards 1 and the cross-correlation coefficient that is tending towards 0,, has good correlation properties that is.
This method further comprises: the set of prenoticing the end side lead code relevant with first leading symbol.
Adopted method of the present invention, do not changed original leading (that is, second is leading), so can not influence the terminal of producing, kept best compatibility with original system to original leading reception and detection according to existing standard.In addition, owing to introduced new leading symbol, terminal not only can obtain original leading information of carrying, as Segment information and IDCell information, but also can obtain the information that new leading symbol carries, as grouping information or bandwidth information etc., dwindled leading hunting zone greatly, simplified the initialization access process.
Other features and advantages of the present invention will be set forth in the following description, and, partly from specification, become apparent, perhaps understand by implementing the present invention.Purpose of the present invention and other advantages can realize and obtain by specifically noted structure in the specification of being write, claims and accompanying drawing.
Description of drawings
Accompanying drawing is used to provide further understanding of the present invention, and constitutes the part of specification, is used from explanation the present invention with embodiments of the invention one, is not construed as limiting the invention.In the accompanying drawings:
Fig. 1 is the flow chart that illustrates according to the leading transmission method of ofdm system of the present invention;
Fig. 2 is the schematic diagram that former leading position in frame structure is shown;
Fig. 3 illustrates according to new leading frame structure schematic diagram when sending on the part bandwidth of the present invention; And
Fig. 4 illustrates according to new leading frame structure schematic diagram when sending on whole bandwidth of the present invention.
Embodiment
Below in conjunction with accompanying drawing the preferred embodiments of the present invention are described, should be appreciated that preferred embodiment described herein only is used for description and interpretation the present invention, and be not used in qualification the present invention.
Fig. 1 is the flow chart that illustrates according to the leading transmission method of ofdm system of the present invention.
With reference to Fig. 2, comprise following processing: step S102 according to the leading transmission method of ofdm system of the present invention, determine to send to the information of end side; Step S104 determines first leading symbol (that is new leading symbol) according to information; And step S106, base station side sends to end side with first leading symbol and second leading symbol (that is former leading symbol).
Wherein, first leading symbol and second leading symbol account for a symbol in time, be made of subcarrier on frequency domain, second leading symbol existed before definite first leading symbol, and did not change the structure and the position of second leading symbol after determining first leading symbol.
Preferably, before sending first leading symbol and second leading symbol, the lead code of second leading symbol is divided into groups.
The position of first leading symbol is before or after second leading symbol, and the position of first leading symbol and second leading symbol is continuous or discontinuous.
Information is one or more in the grouping information of lead code of system bandwidth, second leading symbol and the number of transmit antennas.
In the frequency domain structure of first leading symbol, its lead code is positioned on the part bandwidth or whole bandwidth of system.
In the frequency domain of first leading symbol structure, its lead code equally spaced be mapped on the subcarrier or Continuous Mappings to subcarrier.
The lead code relevant with first leading symbol has auto-correlation coefficient that is tending towards 1 and the cross-correlation coefficient that is tending towards 0,, has good correlation properties that is.
This method further comprises: the set of prenoticing the end side lead code relevant with first leading symbol.
Below, with reference to Fig. 2 to Fig. 4 specific embodiments of the invention are described.
Fig. 2 is the schematic diagram that the position of former leading symbol in frame structure is shown; Fig. 3 is the frame structure schematic diagram when new leading symbol according to the present invention being shown sending on the part bandwidth; And Fig. 4 is the frame structure schematic diagram when new leading symbol according to the present invention being shown sending on whole bandwidth.
With the IEEE802.16e system is example, and 16e is leading to have 114 under a bandwidth, and the corresponding different fast Fourier transform (FFT) size of different bandwidth and the length of lead code.
Adopting the leading system definition afterwards of the method for the invention design is new system, and original 16e system is called old system.Notice that " newly " herein and the saying of " old " are just for the facility on illustrating.
Assumed condition is as follows: base station (IDCell=1) bandwidth of new system is 10MHz, and corresponding FFT size is 1024, new leading send on the part bandwidth (for example, being total to about midbandwidth in the scope of 5MHz); Certain terminal A (Segment=0) needs to search for the leading of this base station in the initialization access procedure; Former leading position in frame structure as shown in Figure 2; Suppose the new leading former leading previous symbol that is positioned at, new leadingly on the part bandwidth, send, as shown in Figure 3; And there is not an integer frequency offset.
At first, determine to send to the information (for example, bandwidth information and grouping information) of end side, therefore need be to 114 leading groupings, hypothesis is divided into 8 groups in the present embodiment, and 14～15 every group are not waited.In addition, suppose that the bandwidth information of carrying is 5MHz, 10MHz and 20MHz.Therefore, need 24 new targeting sequencings, each sequence and a bandwidth, a packet number are corresponding.
Then, the new targeting sequencing P of selection and system parameters correspondence
1, be mapped on the OFDM subcarrier of 5MHz bandwidth correspondence.
Then, with new leading symbol P
1With former leading symbol P
0Be inserted in the frame structure shown in Figure 3, and it is sent.
At receiving terminal, terminal A carries out the estimation and the compensation of frame synchronization, fractional part of frequency offset earlier, forwards frequency domain then to.If new leading symbol has time domain repeatability, then can utilize this point to carry out described fractional part of frequency offset and estimate; And if new leading symbol does not have time domain repeatability, then can utilize the Cyclic Prefix of OFDM symbol to carry out described frequency offset estimating.The method of these frequency offset estimating has a lot of algorithms, just repeats no more at this.Then, carry out relevant matches, thereby obtain the parameter information that the base station passes over.
Terminal A need carry out 39 correlations at most to two leading symbols in the down initial access procedure, just can obtain corresponding information: 10MHz bandwidth, these three parameters of IDCell, Segment.Finish synchronously then and read control information.For this situation, 342 correlations need be carried out at most equally, these three parameters of bandwidth, IDCell and Segment could be obtained the former leading coupling of old system.This shows that receiving terminal has significantly reduced the number of times of search, has obtained more information simultaneously.
Situation shown in Figure 4 is similar to situation shown in Figure 3, and just transmission is newly leading on whole bandwidth, just repeats no more herein.
Adopted method of the present invention, do not changed original leading symbol (that is, second leading symbol), so can not influence the terminal of producing, kept best compatibility with original system to original leading reception and detection according to existing standard.In addition, owing to introduced new leading symbol, terminal not only can obtain original leading information of carrying, as Segment information and IDCell information, but also can obtain the information that new leading symbol carries, as grouping information or bandwidth information etc., dwindled leading hunting zone greatly, simplified the initialization access process.
Be the preferred embodiments of the present invention only below, be not limited to the present invention, for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (6)
1. the leading transmission method of an ofdm system is characterized in that, described method comprises following processing:
Step S102, definite information that need send to end side, wherein, described information is grouping information and bandwidth information;
Step S104, before sending first leading symbol and second leading symbol, lead code to described second leading symbol is divided into groups, wherein, described first leading symbol and described second leading symbol account for a symbol in time, on frequency domain, constitute by subcarrier, described second leading symbol is former leading symbol, described second leading symbol existed before definite described first leading symbol, and did not change the structure and the position of described second leading symbol after determining described first leading symbol; And
Step S106, base station side sends to described end side with described first leading symbol and described second leading symbol.
2. method according to claim 1 is characterized in that, the position of described first leading symbol is before or after described second leading symbol, and the position of described first leading symbol and described second leading symbol is continuous or discontinuous.
3. method according to claim 1 and 2 is characterized in that, in the frequency domain structure of described first leading symbol, its lead code is positioned on the part bandwidth or whole bandwidth of system.
4. method according to claim 1 and 2 is characterized in that, in the frequency domain of described first leading symbol structure, its lead code equally spaced be mapped on the subcarrier or Continuous Mappings to subcarrier.
5. method according to claim 1 and 2 is characterized in that, the lead code relevant with described first leading symbol has auto-correlation coefficient that is tending towards 1 and the cross-correlation coefficient that is tending towards 0.
6. method according to claim 1 and 2 is characterized in that, further comprises: the set of prenoticing the described end side lead code relevant with described first leading symbol.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100042850A CN101222467B (en) | 2008-01-29 | 2008-01-29 | Leading transmission method of orthogonal frequency division multiplexing system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100042850A CN101222467B (en) | 2008-01-29 | 2008-01-29 | Leading transmission method of orthogonal frequency division multiplexing system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101222467A CN101222467A (en) | 2008-07-16 |
| CN101222467B true CN101222467B (en) | 2010-12-01 |
Family
ID=39632043
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2008100042850A Expired - Fee Related CN101222467B (en) | 2008-01-29 | 2008-01-29 | Leading transmission method of orthogonal frequency division multiplexing system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101222467B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004049618A1 (en) * | 2002-11-26 | 2004-06-10 | Electronics And Telecommunications Research Institute | Method and apparatus for embodying and synchronizing downlink signal in mobile communication system and method for searching cell using the same |
| CN1996985A (en) * | 2006-06-26 | 2007-07-11 | 浙江大学 | Method and device for downlink frame synchronization |
| CN101282128A (en) * | 2007-04-03 | 2008-10-08 | 中兴通讯股份有限公司 | Method for reinforcing predecessor of broadband radio communication system |
| CN101286753A (en) * | 2007-04-11 | 2008-10-15 | 中兴通讯股份有限公司 | Lead code sending and receiving method for wideband wireless communication system |
| CN101420261A (en) * | 2007-10-26 | 2009-04-29 | 中兴通讯股份有限公司 | Synchronous information sending method of OFDM system and cell searching method |
| CN101420402A (en) * | 2007-10-26 | 2009-04-29 | 中兴通讯股份有限公司 | Lead code sending method and cell searching method for OFDM system |
-
2008
- 2008-01-29 CN CN2008100042850A patent/CN101222467B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004049618A1 (en) * | 2002-11-26 | 2004-06-10 | Electronics And Telecommunications Research Institute | Method and apparatus for embodying and synchronizing downlink signal in mobile communication system and method for searching cell using the same |
| CN1996985A (en) * | 2006-06-26 | 2007-07-11 | 浙江大学 | Method and device for downlink frame synchronization |
| CN101282128A (en) * | 2007-04-03 | 2008-10-08 | 中兴通讯股份有限公司 | Method for reinforcing predecessor of broadband radio communication system |
| CN101286753A (en) * | 2007-04-11 | 2008-10-15 | 中兴通讯股份有限公司 | Lead code sending and receiving method for wideband wireless communication system |
| CN101420261A (en) * | 2007-10-26 | 2009-04-29 | 中兴通讯股份有限公司 | Synchronous information sending method of OFDM system and cell searching method |
| CN101420402A (en) * | 2007-10-26 | 2009-04-29 | 中兴通讯股份有限公司 | Lead code sending method and cell searching method for OFDM system |
Non-Patent Citations (1)
| Title |
|---|
| Sun Changyin等.IEEE C802.16m-08/385:DL Preamble Design for 802.16m.IEEE 802.16 Broadband Wireless Access Working Group.2008,1-8. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101222467A (en) | 2008-07-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7558293B2 (en) | Method for detecting initial operation mode in wireless communication system employing OFDMA scheme | |
| US7859988B2 (en) | System for flexible cyclic prefix length for preamble symbols in an OFDM based communication system | |
| US8873488B2 (en) | Method and apparatus for transmitting synchronization signals in an OFDM based cellular communications system | |
| US20060176966A1 (en) | Variable cyclic prefix in mixed-mode wireless communication systems | |
| US20070258358A1 (en) | Method and apparatus for enhancing the detection of common control channel in orthogonal frequency division multiple access-based cellular communication system | |
| US20090196163A1 (en) | Bandwidth asymmetric communication system based on ofdm and tdma | |
| US8265200B2 (en) | Method and system for receiver synchronization | |
| WO2008008924A2 (en) | Uplink access request in an ofdm communication environment | |
| JP2011524142A (en) | Method and apparatus in a wireless communication system | |
| CN101682416B (en) | Method and apparatus for transmitting and receiving common control channels in a mobile communication system | |
| US8036190B2 (en) | Methods and devices for allocating data in a wireless communication system | |
| CN1909536A (en) | Communication method and device for crossing frequency division multiple address-time division multiple address | |
| CN101286753B (en) | Lead code sending and receiving method for wideband wireless communication system | |
| CN101997803B (en) | Block transmission method and system for digital signal | |
| CN101099361A (en) | Method of obtaining time synchronization in OFDM mobile communication system | |
| CN101282128B (en) | Method for reinforcing predecessor of broadband radio communication system | |
| KR101108781B1 (en) | Method for transmitting data in wireless communication system | |
| US8730998B2 (en) | Method and apparatus for transmitting/receiving control information in broadcast communication system | |
| CN101222467B (en) | Leading transmission method of orthogonal frequency division multiplexing system | |
| KR101792505B1 (en) | The mobile station apparatus and method of receiving signal in wireless communication system supporting a plurality of wireless communication schemes | |
| CN101488932B (en) | Method, device and system for positioning broadcast channel in orthogonal frequency division multiplexing system | |
| WO2019001702A1 (en) | Techniques for processing radio signals comprising code and replica of the code | |
| CN101282318A (en) | Novel method for transmitting prefix of OFDM 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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20101201 Termination date: 20180129 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |