CN101374133A - Method and apparatus for distributing multi-district pilots, method and apparatus for transmitting data - Google Patents
Method and apparatus for distributing multi-district pilots, method and apparatus for transmitting data Download PDFInfo
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Abstract
The invention discloses a multi-cell pilot frequency distribution method applied in an orthogonal frequency-division multiplexing system, which comprises the following steps: generating at least two different original frequency hopping sequences according to a predetermined pilot frequency domain; generating a combined frequency hopping sequence (having length greater than that of the original frequency hopping sequences) from at least two different original frequency hopping sequences; generating different pilot frequency structures satisfying collision threshold requirements based on the combined frequency hopping sequence; and distributing the generated pilot frequency structures to each cell. The invention also discloses a pilot frequency distribution device. The invention also discloses a data transmitting method and a device. By adopting the technical proposal provided by the invention, the pilot frequency interference resistance among different cells is improved so as to improve channel estimation precision.
Description
Technical field
The invention belongs to communication technical field, relate in particular to a kind of method of multi-district pilots distribution and the method and the device of device and the transmission of a kind of data.
Background technology
In communication system, usually adopt coherent demodulation to improve the performance of receiving terminal, and realize coherent demodulation need receiving terminal know data in transmission course the channel conditions of process, for this reason, the receiving terminal known pilot signal that need send according to transmitting terminal to data the channel of process estimate.
For example, at OFDM (OFDM, Orthogonal Frequency DivisionMultiplexing) in the system, transmitting terminal need receiving terminal is known pilot signals carry fixedly sent (other position carry on the running time-frequency resource have data) in the time-frequency position on the running time-frequency resource some, and then receiving terminal utilize these pilot signals just can to data the channel conditions of process estimate.
Be under 1 the situation at frequency duplex factor as one, different districts takies identical frequency resource, if pilot signal present position on running time-frequency resource that neighbor cell sends is identical, then the pilot signal that receives of receiving terminal will be subjected to the strong jamming between the neighbor cell, thereby influence the accuracy of channel estimating, and then reduce the receptivity of receiving terminal.In order to reduce the pilot signal phase mutual interference between the neighbor cell, the pilot signal quadrature or the accurate quadrature that need neighbor cell to send, and then just need be adjacent each cell allocation quadrature or quasi-orthogonal pilot configuration.Each sub-district is when the needs pilot signal transmitted, according to the pilot configuration that is assigned with pilot signals carry is sent on the running time-frequency resource of correspondence, owing to distribute to the orthogonal or accurate quadrature of pilot configuration of neighbor cell, so the pilot signal that sends of each neighbor cell also quadrature or accurate quadrature.
So-called pilot signal quadrature is meant pilot signal not collision (promptly overlapping) fully on running time-frequency resource that different districts sends, and different skews is promptly arranged on frequency domain and/or time domain.See also Fig. 1, it is the pilot signal quadrature schematic diagram that different districts sends in the prior art.In Fig. 1, the ater pilot signal that sub-district 1 sends has different skews with the horizontal cross shade pilot signal that sub-district 2 sends on frequency domain, therefore quadrature on frequency domain; The ater pilot signal that sub-district 1 sends has different skews with the vertical shade pilot signal of level that sub-district 3 sends on time domain, therefore quadrature on time domain; The ater pilot signal that sub-district 1 sends all has different skews with the oblique shade pilot signal that sub-district 4 sends on frequency domain and time domain, therefore at time domain and the equal quadrature of frequency domain.
The accurate quadrature of so-called pilot signal is meant the incomplete quadrature of pilot signal that different districts sends, and the pilot signal that carrying is gone up in promptly indivedual time-frequency configurations may bump (promptly overlapping), but the collision threshold requirement that collision is counted and satisfied system.For example, the collision thresholding of system requirements is to collide to count to be lower than 4, then as long as the point that the pilot signal that different districts sends is piled up is lower than 4, the pilot signal that receives of the receiving terminal degree that is subjected to neighbor cell interference just belongs in the acceptable scope so, and then receiving terminal can carry out channel estimating comparatively accurately in view of the above.Be appreciated that the situation at the pilot signal quadrature, can be considered as that collision counts is zero, satisfies the requirement of collision thresholding certainly.
In order to guarantee that receiving terminal carries out the channel estimating of certain order of accuarcy, the pilot signal that needs each adjacent sub-district to send must satisfy the predetermined collision threshold requirement of system, i.e. pilot signal quadrature or accurate quadrature.Owing to be subjected to the pilot configuration limited in number, each sub-district can only be selected in limited pilot configuration, so some non-adjacent sub-district will send identical pilot signal.But, pilot signal interference between the non-adjacent sub-district is not have fully, therefore, anti-Pilot Interference ability in system between different districts is directly related with the number of pilots that can satisfy the collision threshold requirement, so the pilot frequency distribution of how to carry out many sub-districts has become an important research content in frequency division multiplexing field.
The scheme that multi-district pilots distributes in existing a kind of Frequency Division Multiplexing system is: OFDM mark space (the being called for short the pilot tone time domain interval) N on time domain generates a frequency hop sequences of corresponding length at the subcarrier spacing on the frequency domain (being called for short the pilot tone frequency domain interval) M or pilot signal based on pilot signal, utilize multiple quadrature of this frequency hop sequences regeneration or quasi-orthogonal pilot configuration then, and then these pilot configurations are distributed to each sub-district use.And then, when each sub-district needs pilot signal transmitted, on running time-frequency resource, carry pilot signal according to the pilot configuration that is assigned with and sent.
See also Fig. 2, it is a kind of pilot configuration schematic diagram of the prior art.In this pilot configuration, M=5 subcarrier of pilot tone frequency domain interval, N=6 OFDM symbol of pilot tone time domain interval.Because the length of frequency hop sequences can be corresponding to M, also can be corresponding to N, this schematic diagram is being that example describes corresponding to M.Because M=5, therefore the length of the frequency hop sequences that generates is at most 5, particular content as for this frequency hop sequences can have various ways according to existing frequency hop sequences generation technique, for example a kind of Costas (Coase tower) sequence is { 1,4,3,5,2}, this Costas sequence is corresponding to ater pilot configuration shown in Figure 2.
To { 1,4,3,5, this Costas sequence of 2}, with a subcarrier is that a frequency displacement unit carries out cyclic shift on frequency domain, can obtain 5 kinds of sequences, and then be that a time shift unit carries out cyclic shift on time domain with 6 OFDM symbols respectively, can obtain M * M=5 * 5=25 kind sequence altogether resulting these 5 kinds of sequences, every kind of sequence is corresponding to a kind of pilot configuration, so just can obtain 25 kinds of different pilot configurations.
Collision relation between resulting these 25 kinds of pilot configurations can reflect by corresponding SDA (Side-lobe Distribution Array, secondary lobe distributes array), as shown in Figure 3.
In Fig. 3, the representative of commensurate's grid present position is not with { 1,4,3,5, this Costas sequence of 2} is carried out different time-frequency displacements, numeral in the unit grid is then represented: the pilot configuration of the sequence correspondence that obtains after the displacement and former sequence ({ 1,4,3,5, the 2}) point of impingement number between the Dui Ying pilot configuration (being ater pilot configuration shown in Figure 2).For example, among Fig. 3 second row secondary series, after subcarrier of frequency domain cocycle displacement, a time domain cocycle time shift unit of displacement (6 OFDM symbols), the pilot configuration that the pilot configuration of the new sequence correspondence that obtains is corresponding with former sequence has two points of impingement with former sequence in expression.Count and be lower than 2 if the collision thresholding of a communication system is collision, then above-mentioned based on 1,4,3,5, just 25 pilot configurations that this Costas sequence of 2} generates satisfy the collision threshold requirement of this system.
The inventor finds in realizing process of the present invention, the pilot configuration that existing multi-district pilots allocative decision is can only be for very limited cell allocation different, in other words, each sub-district can only be selected to use in the limited pilot configuration that is provided, identical pilot signal is had to send in therefore a lot of sub-districts, and then the anti-Pilot Interference ability between different districts is relatively poor, causes the precision of channel estimation of receiving terminal also lower.
Summary of the invention
Method and device that the embodiment of the invention provides a kind of multi-district pilots to distribute, can satisfy the different pilot configurations of collision threshold requirement for more cell allocation, and then make that the ability of anti-Pilot Interference improves between different districts, thereby improve channel estimated accuracy.
The method that the embodiment of the invention provides a kind of multi-district pilots to distribute is used for ofdm system, generates at least two kinds of different original frequency hop sequences according to predetermined pilot interval; At least two kinds of different described original frequency hop sequences are generated the combination frequency hop sequences, and the length of described combination frequency hop sequences is greater than the length of described original frequency hop sequences; Generate the different pilot configurations that satisfy the collision threshold requirement based on described combination frequency hop sequences; The pilot configuration of described generation is distributed to each sub-district.
The embodiment of the invention also provides a kind of realization multi-district pilots assigned unit, is used for ofdm system, comprising: original frequency hop sequences generation unit, in order to generate at least two kinds of different original frequency hop sequences according to predetermined pilot interval; Combination frequency hop sequences generation unit, in order at least two kinds of different described original frequency hop sequences are generated the combination frequency hop sequences, the length of described combination frequency hop sequences is greater than the length of described original frequency hop sequences; Pilot generation unit is in order to generate the different pilot configurations that satisfy the collision threshold requirement based on described combination frequency hop sequences; Each sub-district is distributed in order to the pilot configuration that described pilot generation unit is generated in the pilot frequency distribution unit.
The method that the embodiment of the invention also provides a kind of data to send is used for ofdm system, and data to be sent are carried out chnnel coding; Data to be sent after the described chnnel coding are modulated; Data-carrying to be sent after the described modulation is spaced apart on the running time-frequency resource that 5 subcarriers, pilot tone time domain interval are 6 OFDM symbols at the pilot tone frequency domain sends.
The embodiment of the invention also provides a kind of device of realizing that data send, is used for ofdm system, and comprising: coding unit is used for data to be sent are carried out chnnel coding; Modulating unit is used for the data to be sent that described encoded unit carries out after the chnnel coding are modulated; Transmitting element is used for described Data-carrying to be sent after modulating unit is modulated is spaced apart on the running time-frequency resource that 5 subcarriers, pilot tone time domain interval are 6 OFDM symbols at the pilot tone frequency domain and sends.
By above technical scheme as can be seen, in one embodiment of the invention, because at least two kinds of different original frequency hop sequences are generated the combination frequency hop sequences, and should make up the length of the length of frequency hop sequences greater than described original frequency hop sequences, therefore make up the different pilot configuration numbers of the satisfied collision threshold requirement of frequency hop sequences generation based on this, different pilot configuration numbers than the satisfied collision threshold requirement that generates based on an original frequency hop sequences are many, therefore, can be the more different pilot configuration of cell allocation, make that the ability of anti-Pilot Interference increases between different districts, thereby improved channel estimated accuracy.
Description of drawings
Fig. 1 is the quadrature schematic diagram of the pilot signal that different districts sends in the prior art;
Fig. 2 is a kind of pilot configuration schematic diagram of the prior art;
Fig. 3 is the SDA schematic diagram of a kind of frequency hop sequences in the prior art;
The method first embodiment flow chart that Fig. 4 distributes for multi-district pilots of the present invention;
Fig. 5 is the SDA schematic diagram of a kind of frequency hop sequences among the present invention;
Fig. 6 is a kind of pilot configuration schematic diagram among the present invention;
The method second embodiment flow chart that Fig. 7 distributes for multi-district pilots of the present invention;
Fig. 8 realizes multi-district pilots assigned unit example structure schematic diagram for the present invention;
The method embodiment flow chart that Fig. 9 sends for data of the present invention;
Figure 10 a to Figure 10 e is 5 kinds of specific implementation schematic diagrames of a kind of pilot configuration among the present invention;
Figure 11 realizes the device example structure schematic diagram that data send for the present invention.
Embodiment
Below in conjunction with accompanying drawing various embodiments of the present invention are elaborated.
See also Fig. 4, the method first embodiment flow chart that it distributes for multi-district pilots of the present invention.The described technical scheme of present embodiment is used for ofdm system.
Step 410: generate at least two kinds of different original frequency hop sequences according to predetermined pilot tone frequency domain interval.Described pilot tone frequency domain interval specifically is meant the subcarrier spacing (for subsequent descriptions convenient all with M represent pilot tone frequency domain interval) of pilot signal on frequency domain.Described original frequency hop sequences is the frequency hop sequences that directly generates according to prior art, for the embodiment of the invention in the combination frequency hop sequences distinguish mutually, so be referred to as original frequency hop sequences.Described original frequency hop sequences can be Costas sequence, Latin sequence or linear conguential sequences etc.
The front is mentioned in background technology, if the pilot tone frequency domain interval determines that then the maximum length of the various original frequency hop sequences that generate according to this pilot tone frequency domain interval is determined.For example, if M=5, then the maximum length of the various frequency hop sequences of Chan Shenging also is 5.Need to prove that the original frequency hop sequences length that generates in this step can be the maximum length corresponding with the pilot tone frequency domain interval, also can be less than this maximum length.The original frequency hop sequences that generates in this step can be two kinds, also can be two or more.Though the maximum length of every kind of frequency hop sequences is identical, particular content can be different.With M=5 is example, can generate various frequency hop sequences, as a Costas sequence 2,5,3,4,1} and the 2nd Costas sequence 5,3,2,4,1}.As can be seen, though the length of a Costas sequence and the 2nd Costas sequence all is 5, the particular content difference of sequence.
Step 420: at least two kinds of different described original frequency hop sequences are generated the combination frequency hop sequences that satisfies the collision threshold requirement, and the length of described combination frequency hop sequences is greater than the length of described original frequency hop sequences.
Owing under certain pilot tone frequency domain interval, can generate multiple different original frequency hop sequences.If generated multiple original frequency hop sequences, just can adopt the mode that comprises in being combined in so, generate multiple combination frequency hop sequences, promptly form the set of a combination frequency hop sequences.The front was carried, and for an original frequency hop sequences, can adopt existing SDA technology to investigate based on the collision situation between the various pilot configurations of this sequence generation.Therefore, can adopt the SDA technology, from described combination frequency hop sequences set, search out a combination frequency hop sequences that satisfies this collision threshold requirement according to the collision thresholding of system's regulation.Need to prove, can concentrate earlier to generate several combination frequency hop sequences (i.e. combination frequency hop sequences set), and then adopt the SDA technology to collide Threshold detection successively, a last therefrom selected combination frequency hop sequences that satisfies the collision threshold requirement; Also can be after generating a combination frequency hop sequences, just it is collided Threshold detection, if do not satisfy the requirement of collision gate limit, a kind of combination frequency hop sequences under the regeneration.This shows that first kind of combination frequency hop sequences also not getting rid of generation just satisfies the situation of collision threshold requirement, in this case, just do not need to generate the combination frequency hop sequences and gathered.Need to prove that when detecting a kind of combination frequency hop sequences and whether satisfy collision and require, the technology of employing is including, but not limited to the SDA technology.
The step that at least two kinds of different original frequency hop sequences are generated the combination frequency hop sequences also has multiple specific implementation.For example, at first at least two kinds of different original frequency hop sequences combinations, will resulting new sequence as making up frequency hop sequences.With an aforementioned Costas sequence 2,5,3,4,1} and the 2nd Costas sequence 5,3,2,4,1} is an example, after these two original frequency hop sequences combinations, obtain new sequence 2,5,3,4,1,5,3,2,4,1}, should new sequence as a kind of combination frequency hop sequences.Again for example, at first at least two kinds of different original frequency hop sequences combinations, and then to the deletion of the sequence after combination specific bit, with the sequence after the deletion specific bit as the combination frequency hop sequences.Still with an aforementioned Costas sequence 2,5,3,4,1} and the 2nd Costas sequence { 5,3,2,4,1} is an example, at first with these two original frequency hop sequences combinations, obtains new sequence { 2,5,3,4,1,5,3,2,4,1}, deletion specific bit wherein then, as delete last two, just obtain new sequence { 2,5,3,4,1,5,3,2}, should new sequence as a kind of combination frequency hop sequences.
Step 430: generate the different pilot configurations that satisfy described collision threshold requirement based on described combination frequency hop sequences.
No matter in step 420, adopt which kind of embodiment,, can make up frequency hop sequences based on this and generate the different pilot configurations that satisfy described collision threshold requirement as long as obtain a kind of combination frequency hop sequences of satisfied collision threshold requirement.
For example, suppose between the pilot tone frequency domain it is M subcarrier, the pilot tone time domain interval is a N OFDM symbol, and the length of each original frequency hop sequences is M, and the combination frequency hop sequences is directly to be combined by two original frequency hop sequences, and then the length of this combination frequency hop sequences is 2M.And then, should make up frequency hop sequences is that a frequency displacement unit carries out cyclic shift with a subcarrier on frequency domain, can obtain M kind sequence (corresponding to M kind pilot configuration), and then be that a time shift unit carries out cyclic shift on time domain with N OFDM symbol respectively to this M kind sequence, so can obtain M * 2M=2M altogether
2Plant different sequences, can obtain M * 2M=2M
2Plant different pilot configurations.Because that combination frequency hop sequences that searches out in step 420 before this satisfies the collision threshold requirement, therefore M * 2M kind the pilot configuration that generates based on this combination frequency hop sequences also satisfies the collision threshold requirement.
Step 440: the pilot configuration of described generation is distributed to each sub-district.The described pilot configuration that is assigned to respective cell carries the position foundation of pilot signal on running time-frequency resource as this sub-district.
Owing to generated the multiple pilot configuration of satisfied collision thresholding, therefore, these pilot configurations can have been distributed to each sub-district.Particularly, be each cell allocation a kind of pilot configuration wherein, be the pilot configuration difference of each adjacent cell allocation.
If there are a plurality of antennas certain sub-district, promptly need by many antenna transmission pilot signal, then can give a kind of pilot configuration of each antenna assignment of this sub-district.Because the pilot signal of same each antenna transmission of cell base station can think to arrive synchronously receiving terminal, therefore, for the pilot configuration that step 430 is generated can be distributed to sub-district as much as possible, make number of cells that system can hold as much as possible, then can for each antenna assignment of same sub-district at the pilot configuration that does not have to have on deviation (being that zero carries promptly), the time domain less deviation on the frequency domain in the deviation on the frequency domain.For example, predetermined pilot tone time domain interval is a N OFDM symbol, and then the deviation of pilot configuration on frequency domain for each antenna assignment of same sub-district is the zero subcarrier, and the deviation on time domain is more than or equal to 1 OFDM symbol and less than N OFDM symbol.
Be each cell allocation behind the pilot configuration, each sub-district is just carried pilot signal according to the pilot configuration that is assigned with and is sent when the needs pilot signal transmitted on running time-frequency resource.
The concrete example that provides from above-mentioned steps 410 to step 440 is that M subcarrier, pilot tone time domain interval are under the resources supplIes of N OFDM symbol in the pilot tone frequency domain interval as can be seen, adopts the first embodiment of the present invention can obtain M * 2M=2M altogether
2Plant the pilot configuration that satisfies the collision threshold requirement, and then under single-antenna case, can be 2M at least
2The pilot configuration that individual cell allocation is different.Even under many antennas situation, as each adjacent sub-district T antenna arranged, also can be 2M at least
2The pilot configuration that individual cell allocation is different.In contrast under equal resources supplIes, adopt prior art at most only to obtain M * M=M
2Plant the pilot configuration that satisfies the collision threshold requirement, and then under single-antenna case, only can be M
2The pilot configuration that individual cell allocation is different.Obviously, the technical scheme that adopts first embodiment of the invention to provide can be the different pilot configuration of more cell allocation, and then improve the ability of anti-Pilot Interference between different districts under equal resources supplIes, has also improved channel estimated accuracy.
The technical scheme that provides at first embodiment is below carried out the supplementary notes of some replacement scheme.
The first, an example that time shift unit is a N OFDM symbol that provides in the above-mentioned first embodiment step 430 is to consider that neighbor cell signal postpones to cause the situation of Pilot Interference, and is not limited to this in the practical application.For example, do not postpone the Pilot Interference problem that may cause if do not consider neighbor cell signal, then a time shift unit can be an OFDM symbol.Again for example, the Pilot Interference that neighbor cell signal delay with due regard to may cause, adopting a time shift unit is 3 or 4 OFDM symbols.This shows that when generating the pilot configuration that satisfies the collision threshold requirement based on the combination frequency hop sequences, the time shift unit of employing can be any one in 1-N the OFDM symbol.
The second, among above-mentioned first embodiment, at first generate the combination frequency hop sequences that satisfies the collision threshold requirement, and then generate different pilot configurations based on this combination frequency hop sequences that satisfies the collision threshold requirement.Just because of described combination frequency hop sequences is to satisfy the collision threshold requirement, and therefore the different pilot configurations that generate based on this combination frequency hop sequences must satisfy the collision threshold requirement.But, do not get rid of in the practical application yet and at first generate a combination frequency hop sequences (not knowing promptly whether this combination frequency hop sequences satisfies the collision threshold requirement) that does not pass through collision detection, and then generate various pilot configurations, and then detect each pilot configuration that is generated and whether satisfy the collision threshold requirement based on this combination frequency hop sequences.Threshold requirement satisfies if each pilot configuration that generates satisfies collision, uses just then distribute to each neighbor cell; If do not satisfy, then continue to generate a kind of new combination frequency hop sequences based at least two original frequency hop sequences, and then based on the different pilot configuration of this newly-generated combination frequency hop sequences generation, and then detect each pilot configuration that is generated again and whether satisfy the collision threshold requirement.So repeatedly, till each pilot configuration that finds a combination frequency hop sequences to generate satisfies the collision threshold requirement.
The 3rd, generating in the process of different pilot configurations based on the combination frequency hop sequences, can be described in first embodiment, earlier with the cyclic shift on described combination frequency hop sequences process time domain, the frequency domain, and then obtain multiple sequence, and then go out a kind of pilot configuration based on resulting every kind of sequence correspondence.Also can earlier described composite sequence correspondence be gone out a kind of pilot configuration, carry out cyclic shift on time domain, the frequency domain based on this pilot configuration then, and then obtain various pilot configurations.
Those skilled in the art are clearer to understand the embodiment of the invention in order to make, and with predetermined M=5 subcarrier of pilot tone frequency domain interval, N=6 OFDM symbol of pilot tone time domain interval is example below, provides a kind of embodiment of employing first embodiment of the invention.
At first,, generate two kinds of different original frequency hop sequences according to M=5, as a Costas sequence 2,5,3,4,1} and the 2nd Costas sequence 5,3,2,4,1}.Then, with a Costas sequence and the 2nd Costas combined sequence, generation length is 10 combination frequency hop sequences { 2,5,3,4,1,5,3,2,4,1}, and the SDA of this combination frequency hop sequences investigated, judgement counts whether satisfy the requirement of collision thresholding based on the collision between the multiple pilot configuration of this combination frequency hop sequences generation, and the predetermined collision thresholding of supposing the system is that the collision between the various pilot configurations is counted less than 5.
See also Fig. 5, its for the combination frequency hop sequences 2,5,3,4,1,5,3,2,4, the SDA schematic diagram of 1}.As can be seen from Figure 5, the pilot configuration that can generate based on this combination frequency hop sequences has 50, and the collision between most pilot configurations is counted and is no more than 3, and having only 3 collisions between the pilot configuration to count is 4.If these 50 pilot configurations are distributed to different sub-districts, then in 5 * 60 time, it is at most 4 that the collision of the pilot signal of any two sub-districts is counted, and therefore satisfies the predetermined collision threshold requirement of system.Optionally, in order better to avoid the Pilot Interference between the neighbor cell, can be when arranging net the collision more pilot configuration of counting be distributed to the non-conterminous sub-district of trying one's best by the network planning.
According to the combination frequency hop sequences 2,5,3,4,1,5,3,2,4, and the SDA of 1} as can be known, this combination frequency hop sequences satisfies the collision threshold requirement, generates and satisfies the pilot configuration that collides threshold requirement in being based on this combination frequency hop sequences.Particularly, with { 2,5,3,4,1,5,3,2,4,1} is that a frequency displacement unit carries out cyclic shift on frequency domain with a subcarrier, can obtain 5 kinds of sequences, and then be that a time shift unit carries out cyclic shift on time domain with 6 OFDM symbols respectively to resulting these 5 kinds of sequences, can obtain 5 * 10=50 kind sequence altogether, every kind of sequence is corresponding to a kind of pilot configuration, so just can obtain 50 kinds of different pilot configurations, owing to know combination frequency hop sequences { 2 before this from SDA shown in Figure 5,5,3,4,1,5,3,2,4,1} satisfies the collision threshold requirement, and therefore, 50 kinds of frequency hop sequences that generate based on this combination frequency hop sequences also satisfy the collision threshold requirement.
{ 2,5,3,4,1,5,3,2,4, the pilot configuration of this sequence correspondence of 1} as shown in Figure 6.5 * 60 the time that heavy black line is surrounded is made up of the 1st to the 5th subcarrier, the 1st to the 60th OFDM symbol.Pilot signal placement location in this Resource Block is with { 2,5,3,4,1,5,3,2,4, this sequence of 1} is corresponding, and promptly in the 1st OFDM symbol of this time, pilot signal is placed on the 2nd subcarrier; In the 7th OFDM symbol of this time, pilot signal is placed on the 5th subcarrier; In the 13rd OFDM symbol of this time, pilot signal is placed on the 3rd subcarrier; Follow-up and the like, repeat no more.As can be seen from Figure 6, this pilot configuration comprises the time-frequency piece that some time of surrounding with heavy black line have identical patterns, therefore, all the other time is repeated no more.
Except this pilot configuration shown in Figure 6, remaining 49 kinds of pilot configuration all is by { 2,5,3,4,1,5,3,2,4,1} carries out that cyclic shift on time domain, the frequency domain obtains, so detailed description no longer one by one with sequence.
See also Fig. 7, the method second embodiment flow chart that it distributes for multi-district pilots of the present invention.The described technical scheme of present embodiment is used for ofdm system.Present embodiment and the first embodiment main distinction part shown in Figure 4: be to generate original frequency hop sequences in the present embodiment, and be to generate original frequency hop sequences among first embodiment according to predetermined pilot tone frequency domain interval according to predetermined pilot tone time domain interval.
Step 710: generate at least two kinds of different original frequency hop sequences according to predetermined pilot tone time domain interval.If predetermined pilot tone time domain interval is a N OFDM symbol, then the original frequency hop sequences maximum length of Sheng Chenging is N.
Step 720: at least two kinds of different described original frequency hop sequences are generated the combination frequency hop sequences, and the length of described combination frequency hop sequences is greater than the length of described original frequency hop sequences.This step is identical with step 420 among first embodiment, so repeat no more.
Step 730: generate the different pilot configurations that satisfy described collision threshold requirement based on described combination frequency hop sequences.Because original frequency hop sequences obtains according to the pilot tone time domain interval, therefore, satisfying in the process of each pilot configuration based on making up the frequency hop sequences generation, can be on frequency domain be that a frequency displacement unit carries out cyclic shift with 1 subcarrier, on time domain, be that a time shift unit carries out cyclic shift with 1 OFDM symbol.Certainly, in actual applications, the situation that also not get rid of a time shift unit be 2 above OFDM symbols.
Step 740: the pilot configuration of described generation is distributed to each sub-district.The described pilot configuration that is assigned to respective cell carries the position foundation of pilot signal on running time-frequency resource as this sub-district.After this, described each sub-district is carried pilot signal according to the pilot configuration that is assigned with and is sent when the needs pilot signal transmitted on running time-frequency resource.This step is identical with step 440 among first embodiment, so repeat no more.
Method first embodiment that comprehensive aforementioned multi-district pilots distributes and second embodiment as can be seen, when generating original frequency hop sequences, can be according to predetermined pilot tone frequency domain interval, also can be according to predetermined pilot tone time domain interval.Therefore, above-mentioned two kinds of situations can be summarised as: generate at least two kinds of different original frequency hop sequences according to predetermined pilot interval.Described pilot interval can be the pilot tone frequency domain interval, also can be the pilot tone time domain interval.
See also Fig. 8, it is a multi-district pilots assigned unit example structure schematic diagram of the present invention.The described device of present embodiment is used for ofdm system.Device in the present embodiment comprises original frequency hop sequences generation unit 810, combination frequency hop sequences generation unit 820, pilot generation unit 830 and pilot frequency distribution unit 840.Operation principle below in conjunction with this device is further introduced its internal structure and annexation.
At first, original frequency hop sequences generation unit 810 generates at least two kinds of different original frequency hop sequences according to predetermined pilot tone frequency domain interval.And then combination frequency hop sequences generation unit 820 generates the combination frequency hop sequences with at least two kinds of different described original frequency hop sequences, and the length of described combination frequency hop sequences is greater than the length of described original frequency hop sequences.The mode of described generation combination frequency hop sequences can have multiple specific implementation, and for example the scheme that directly makes up for example earlier makes up the scheme of afterwards deleting again, and particular content can repeat no more with reference to the relevant art feature among the preceding method embodiment herein.
The specific implementation of combination frequency hop sequences generation unit 820 has multiple.For example, combination frequency hop sequences generation unit 820 comprises combined treatment unit and search unit, and wherein, the combined treatment unit is used at least two kinds of different described original frequency hop sequences are generated the set of combination frequency hop sequences; And then search unit searches out a combination frequency hop sequences that satisfies the collision threshold requirement described closing in the frequency hop sequences set.Again for example, combination frequency hop sequences generation unit 820 can only be based on original frequency hop sequences and generate the combination frequency hop sequences, whether do not satisfy the requirement of colliding thresholding and do not remove to detect this combination frequency hop sequences, after each pilot configuration that generates etc. follow-up pilot generation unit 830 does not satisfy the collision gate limit and requires, generate new combination frequency hop sequences by combination frequency hop sequences generation unit 820 again.
After this, pilot generation unit 830 generates the different pilot configurations that satisfy the collision threshold requirement based on the combination frequency hop sequences that combination frequency hop sequences generation unit 820 provides.At last, the pilot configuration that pilot frequency distribution unit 840 generates pilot generation unit 830 is distributed to each sub-district and is used, and the described pilot configuration that is assigned to respective cell carries the position foundation of pilot signal on running time-frequency resource as this sub-district.Situation for many antennas, for the system that makes can hold sub-district as much as possible, pilot frequency distribution unit 840 is the zero subcarrier for the deviation of pilot configuration on frequency domain of each antenna assignment of same sub-district, and the deviation on time domain is less than N OFDM symbol (supposing that predetermined pilot tone time domain interval is a N OFDM symbol).
Embodiment is similar with preceding method, the length of original frequency hop sequences can be corresponding with the pilot tone frequency domain interval, also can be corresponding with the pilot tone time domain interval, therefore, original frequency hop sequences generation unit 810 can generate at least two kinds of different original frequency hop sequences according to predetermined pilot tone frequency domain interval, also can generate at least two kinds of different original frequency hop sequences according to predetermined pilot tone time domain interval.And then original frequency hop sequences generation unit may be summarized to be, and is used for generating at least two kinds of different original frequency hop sequences according to predetermined pilot interval.Described pilot interval can be the pilot tone frequency domain interval, also can be the pilot tone time domain interval.
See also Fig. 9, it is for the sending method embodiment flow chart of data of the present invention.The described technical scheme of present embodiment is used for ofdm system.
Step 910: data to be sent are carried out chnnel coding.This step can adopt the correlation technique of existing channel coding to be achieved, so no longer describe in detail.
Step 920: the data to be sent after the described chnnel coding are modulated.This step can adopt the correlation technique of existing channel coding to be achieved, so no longer describe in detail.
Step 930: the Data-carrying to be sent after the described modulation is spaced apart on the running time-frequency resource that 5 subcarriers, pilot tone time domain interval are 6 OFDM symbols at the pilot tone frequency domain sends.It is that the running time-frequency resource of 6 OFDM symbols shows that what transmitting terminal adopted is that the pilot tone frequency domain is spaced apart 5 subcarriers, the pilot tone time domain interval is the pilot configuration of 6 OFDM symbols that described pilot tone frequency domain is spaced apart 5 subcarriers, pilot tone time domain interval.
In IMT (International mobile telecommunication, international mobile telecommunication)-Advanced system (being the later third generation mobile communication system of 3G), the design of pilot configuration need be considered following parameter: subcarrier spacing 20kHz; CP length 6.25 μ s; Working frequency points 2.5GHz; Resource block size is: 10 subcarrier * 6 OFDM symbols.In addition, according to the demand of IMT-Advanced, when travelling carriage moved with the speed of 350km/h, system should keep preferably that network connects.Therefore the distribution of pilot tone must be able to guarantee under this environment the accuracy to channel estimating.And when short CP (Cyclic Prefix, Cyclic Prefix), a timeslot (time slot) comprises 6 OFDM symbols.
And then in order to satisfy above-mentioned requirements, the pilot configuration that transmitting terminal adopts can be: on frequency domain, 0 pilot tone be spaced apart 5 subcarriers; On time domain, pilot tone be spaced apart 6 OFDM symbols.For the IMT-Advanced system, under single-antenna case, adopt the expense of pilot tone of said structure less-to be about 3.3%, and can guarantee that each Resource Block contains the pilot tone of similar number, help BR (blockrepeat, piece repeats)-realization of OFDMA (Orthogonal Frequency Division Multiplexing, OFDM) technology.
Have the pilot tone frequency domain and be spaced apart 5 subcarriers, pilot tone time domain interval to be that the specific implementation of the pilot configuration of 6 OFDM symbols has multiple, 5 kinds of specific implementations of the above-mentioned pilot configuration shown in Figure 10 a to Figure 10 e.Below 10a to Figure 10 e is introduced respectively in detail.
In Figure 10 a, the pilot tone carrying position that carries in two adjacent OFDM symbol of pilot signal is identical.In Figure 10 b, carry the pilot tone carrying position in two adjacent OFDM symbol of pilot signal, be offset 1 subcarrier mutually.In Figure 10 c, carry the pilot tone carrying position in two adjacent OFDM symbol of pilot signal, be offset 2 subcarriers mutually.In Figure 10 d, carry the pilot tone carrying position in two adjacent OFDM symbol of pilot signal, be offset 3 subcarriers mutually.In Figure 10 e, carry the pilot tone carrying position in two adjacent OFDM symbol of pilot signal, be offset 4 subcarriers mutually.
See also Figure 11, it realizes the device example structure schematic diagram that data send for the present invention.The described device of present embodiment is used for ofdm system.Device described in the present embodiment comprises coding unit 111, modulating unit 112 and transmitting element 113.At first, carry out chnnel coding by 111 pairs of data to be sent of coding unit, its specific implementation can be with reference to existing correlation technique.And then the data to be sent of being undertaken after the chnnel coding by 112 pairs of encoded unit 111 of modulating unit are modulated again, and its specific implementation can be with reference to existing correlation technique.At last, by transmitting element 113 will be after modulating unit 112 be modulated data to be sent, be carried on the pilot tone frequency domain and be spaced apart on the running time-frequency resource that 5 subcarriers, pilot tone time domain interval are 6 OFDM symbols and send.Have the pilot tone frequency domain and be spaced apart 5 subcarriers, pilot tone time domain interval to be that the specific implementation of the pilot configuration of 6 OFDM symbols has multiple, can be referring to 5 kinds of pilot configuration specific implementations shown in Figure 10.
Above-described embodiment of the present invention does not constitute the qualification to protection range of the present invention.Any modification of being done within the spirit and principles in the present invention, be equal to and replace and improvement etc., all should be included within the claim protection range of the present invention.
Claims (13)
1. the method that multi-district pilots distributes is used for ofdm system, it is characterized in that:
Generate at least two kinds of different original frequency hop sequences according to predetermined pilot interval;
At least two kinds of different described original frequency hop sequences are generated the combination frequency hop sequences, and the length of described combination frequency hop sequences is greater than the length of described original frequency hop sequences;
Generate the different pilot configurations that satisfy the collision threshold requirement based on described combination frequency hop sequences;
Described pilot configuration is distributed to each sub-district.
2. method according to claim 1 is characterized in that, at least two kinds of different original frequency hop sequences of described general generate the combination frequency hop sequences and specifically comprise:
With at least two kinds of different described original frequency hop sequences combinations, generate the combination frequency hop sequences;
Perhaps
With at least two kinds of different described original frequency hop sequences combinations; To the deletion of the sequence after described combination specific bit, generate the combination frequency hop sequences.
3. method according to claim 1 is characterized in that, at least two kinds of different original frequency hop sequences of described general generate the combination frequency hop sequences and specifically comprise:
At least two kinds of different described original frequency hop sequences are generated the set of combination frequency hop sequences;
From described combination frequency hop sequences set, search out a kind of combination frequency hop sequences that satisfies the collision threshold requirement.
4. method according to claim 1, it is characterized in that, if there are a plurality of antennas certain sub-district, predetermined pilot tone time domain interval is a N OFDM symbol, then the deviation of pilot configuration on frequency domain for this each antenna assignment of sub-district is the zero subcarrier, and the deviation on time domain is more than or equal to 1 OFDM symbol and less than N OFDM symbol.
5. according to any described method in the claim 1 to 4, it is characterized in that, also comprise:
Described each sub-district is carried pilot signal according to the pilot configuration that is assigned with and is sent when the needs pilot signal transmitted on running time-frequency resource.
6. according to any described method in the claim 1 to 4, it is characterized in that in the pilot configuration of described generation, the pilot tone frequency domain is spaced apart 5 subcarriers, the pilot tone time domain interval is 6 OFDM symbols.
7. according to any described method in the claim 1 to 4, it is characterized in that, describedly generate at least two kinds of different original frequency hop sequences according to predetermined pilot interval and specifically comprise:
Generate at least two kinds of different original frequency hop sequences according to predetermined pilot tone frequency domain interval;
Perhaps
Generate at least two kinds of different original frequency hop sequences according to predetermined pilot tone time domain interval.
8. realize the multi-district pilots assigned unit for one kind, be used for ofdm system, it is characterized in that, comprising:
Original frequency hop sequences generation unit is in order to generate at least two kinds of different original frequency hop sequences according to predetermined pilot interval;
Combination frequency hop sequences generation unit, in order at least two kinds of different described original frequency hop sequences are generated the combination frequency hop sequences, the length of described combination frequency hop sequences is greater than the length of described original frequency hop sequences;
Pilot generation unit is in order to generate the different pilot configurations that satisfy the collision threshold requirement based on described combination frequency hop sequences;
Each sub-district is distributed in order to the pilot configuration that described pilot generation unit is generated in the pilot frequency distribution unit.
9. device according to claim 8 is characterized in that, described combination frequency hop sequences generation unit comprises:
The combined treatment unit is used at least two kinds of different described original frequency hop sequences are generated the set of combination frequency hop sequences;
Search unit is used for searching out a kind of combination frequency hop sequences that satisfies the collision threshold requirement in described combination frequency hop sequences set.
10. according to Claim 8 or 9 described devices, it is characterized in that, if there are a plurality of antennas certain sub-district, predetermined pilot tone time domain interval is a N OFDM symbol, then described pilot frequency distribution unit is the zero subcarrier for the deviation of pilot configuration on frequency domain of this each antenna assignment of sub-district, and the deviation on time domain is more than or equal to 1 OFDM symbol and less than N OFDM symbol.
11. according to Claim 8 or 9 described devices, it is characterized in that described original frequency hop sequences generation unit specifically comprises:
The first original frequency hop sequences generation unit is in order to generate at least two kinds of different original frequency hop sequences according to predetermined pilot tone frequency domain interval;
Perhaps
The second original frequency hop sequences generation unit is in order to generate at least two kinds of different original frequency hop sequences according to predetermined pilot tone time domain interval.
12. the method that data send is used for ofdm system, it is characterized in that:
Data to be sent are carried out chnnel coding;
Data to be sent after the described chnnel coding are modulated;
Data-carrying to be sent after the described modulation is spaced apart on the running time-frequency resource that 5 subcarriers, pilot tone time domain interval are 6 OFDM symbols at the pilot tone frequency domain sends.
13. a device of realizing that data send is used for ofdm system, it is characterized in that, comprising:
Coding unit is used for data to be sent are carried out chnnel coding;
Modulating unit is used for the data to be sent that described encoded unit carries out after the chnnel coding are modulated;
Transmitting element is used for described Data-carrying to be sent after modulating unit is modulated is spaced apart on the running time-frequency resource that 5 subcarriers, pilot tone time domain interval are 6 OFDM symbols at the pilot tone frequency domain and sends.
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| CNA2007101461170A CN101374133A (en) | 2007-08-23 | 2007-08-23 | Method and apparatus for distributing multi-district pilots, method and apparatus for transmitting data |
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| CNA2007101461170A CN101374133A (en) | 2007-08-23 | 2007-08-23 | Method and apparatus for distributing multi-district pilots, method and apparatus for transmitting data |
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| WO2010115300A1 (en) * | 2009-04-07 | 2010-10-14 | 深圳华为通信技术有限公司 | Method and apparatus for transmitting the location pilot signal |
| US8112105B2 (en) | 2008-11-12 | 2012-02-07 | Huawei Technologies Co., Ltd. | Method, apparatus and system for estimating channels |
| CN102769479A (en) * | 2011-05-06 | 2012-11-07 | 北京泰美世纪科技有限公司 | Frequency hopping based digital multi-media broadcast transmitting method and receiving method and systems thereof |
| GB2491836A (en) * | 2011-06-13 | 2012-12-19 | Neul Ltd | Frequency planning |
| WO2015085820A1 (en) * | 2013-12-12 | 2015-06-18 | 华为技术有限公司 | Pilot frequency arrangement determination method and base station |
| US10582434B2 (en) | 2011-06-13 | 2020-03-03 | Huawei Technologies Co., Ltd. | Device and method for deriving alignment information |
| CN110875757A (en) * | 2020-01-19 | 2020-03-10 | 四川大学 | Construction method of low collision region frequency hopping sequence set with wide interval characteristic |
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| US9125199B2 (en) | 2008-11-12 | 2015-09-01 | Huawei Technologies Co., Ltd. | Method and apparatus for channel estimation |
| US8112105B2 (en) | 2008-11-12 | 2012-02-07 | Huawei Technologies Co., Ltd. | Method, apparatus and system for estimating channels |
| US8260211B2 (en) | 2008-11-12 | 2012-09-04 | Huawei Technologies Co., Ltd. | Method, apparatus and system for estimating channels |
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| US8483619B2 (en) | 2008-11-12 | 2013-07-09 | Huawei Technologies Co., Ltd. | Method, apparatus and system for estimating channels |
| US9807761B2 (en) | 2008-11-12 | 2017-10-31 | Huawei Technologies Co., Ltd. | Method and apparatus for channel estimation |
| WO2010115300A1 (en) * | 2009-04-07 | 2010-10-14 | 深圳华为通信技术有限公司 | Method and apparatus for transmitting the location pilot signal |
| CN102204202B (en) * | 2009-04-07 | 2014-10-08 | 华为技术有限公司 | Method and apparatus for transmitting the location pilot signal |
| CN102769479A (en) * | 2011-05-06 | 2012-11-07 | 北京泰美世纪科技有限公司 | Frequency hopping based digital multi-media broadcast transmitting method and receiving method and systems thereof |
| GB2491836B (en) * | 2011-06-13 | 2018-08-22 | Huawei Tech Co Ltd | Frequency planning |
| US10582434B2 (en) | 2011-06-13 | 2020-03-03 | Huawei Technologies Co., Ltd. | Device and method for deriving alignment information |
| GB2491836A (en) * | 2011-06-13 | 2012-12-19 | Neul Ltd | Frequency planning |
| US9794041B2 (en) | 2013-12-12 | 2017-10-17 | Huawei Technologies Co., Ltd | Method for determining pilot arrangement and base station |
| WO2015085820A1 (en) * | 2013-12-12 | 2015-06-18 | 华为技术有限公司 | Pilot frequency arrangement determination method and base station |
| CN110875757A (en) * | 2020-01-19 | 2020-03-10 | 四川大学 | Construction method of low collision region frequency hopping sequence set with wide interval characteristic |
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