Background technology
In wireless communication base station, need processing and a plurality of users' communication.The base station need search out a plurality of multipath signals from the subscriber signal of receiving.In the multipath signal that these search, need to remove the too little multipath of mutual spacing, filter out effective multipath, export to the Rake receiver, be used for the energy of these multipath signals is merged enhancing, reach improve wireless telecommunications anti-interference/decline, support the purpose of remote-wireless communication.
The requirement of multipath screening is: the multipath that on antenna 0/1, searches out, and according to energy sequence arrangement from high to low.Then, according to energy order from high to low, it is too little and be in multipath on the same antenna to remove mutual spacing.At last, obtain effective multipath.
General processing method is: from multipath set to be selected, select the highest multipath of energy, check the distance with other multipaths one by one.If less than preset value, then abandon this multipath; If more than or equal to preset value, then this multipath is put into effective multipath collection.Remaining multipath constitutes new multipath set to be selected, and repetition is above to be handled, and is sky up to multipath set to be selected.
The amount of calculation of this processing method is:
(1) supposes that the multipath number is n in the multipath set to be selected.
(2) the highest multipath of energy in the multipath set to be selected is one by one handled with all remaining multipaths.Therefore need double circular treatment, the outer loop number of times is n, inner loop number of times x-1 (supposing that current outer loop counting is x).
(3) total circulation number of comparisons is:
Total circulation number of comparisons=(n-1)+(n-2)+(n-3)+...+3+2+1=n
2/ 2.
Another similar processing method is: from multipath set to be selected, select the highest multipath of energy, one by one the distance of all multipaths in inspection and the effective multipath set.If less than preset value, then abandon this multipath; If more than or equal to preset value, then this multipath is put into effective multipath collection.Remaining multipath constitutes new multipath set to be selected, and repetition is above to be handled, and is sky up to multipath set to be selected.The needed total circulation number of comparisons of this method is: (n-1)+(n-2)+(n-3)+...+3+2+1=n
2/ 2.If in choosing footpath process kind, the part multipath is dropped, then total circulation number of comparisons can compare n
2/ 2 is few.
The subject matter of above-mentioned two kinds of methods is, in multipath to be selected set, select energy during high multipath at every turn, too near for fear of current multipath with the multipath distance of selecting subsequently, or it is too near with the multipath distance of having selected, all need to travel through the distance of checking with all remaining multipaths, perhaps traversal is checked and the distance of selecting multipath, causes operand to reach n
2Rank.And in the wireless base station, need to handle the multipath information of a large number of users, and user's multipath information is the cycle with 10ms, up to a hundred ground of per second periodic refresh.If adopt the method for such screening multipath, will greatly waste the processing resource, cause the cost of base band veneer to increase or the minimizing of support number of users.
Summary of the invention
Technical problem solved by the invention provides a kind of device that screens the Radio Link multipath, can greatly reduce computational complexity.
Technical scheme is as follows:
A kind of device that screens the Radio Link multipath comprises:
The multipath collection modules is used to store multipath, and described multipath is marked with day wire size and skew;
Flag register is provided with module, be used for corresponding flag register to antenna being set, and set for the first time is 0 or 1 to described flag register; After elected delivery piece is selected effective multipath, described flag register is provided with module handle in the flag register of described effective multipath correspondence position corresponding with the skew of described effective multipath, reaches the set for the second time of d-1 position, the left and right sides, set for the second time is opposite with set for the first time, promptly when set for the first time is 0, set for the second time is 1, when the set first time was 1, set for the second time was 0;
Choose module, be used for extracting the highest multipath of energy from described multipath collection modules, check position corresponding with described skew in the described flag register, reach d-1 position, the left and right sides according to the sky wire size and the skew of described multipath, d represents the minimum spacing of effective multipath; If the position of being checked is identical with the described set first time, show current multipath and the multipath selected between spacing meet the demands, described current multipath is effective multipath; If the position of being checked is inequality with the described set first time, show that current multipath and the multipath spacing of having selected do not meet the demands, and abandon described current multipath.
Preferably, described multipath collection modules is used for sorting according to the height of described multipath energy.
Preferably, described choose module and from described multipath collection modules, take out the highest multipath of energy after, the multipath of the described taking-up of deletion from described multipath collection modules.
Another technical problem solved by the invention provides a kind of method of screening Radio Link multipath of low operand, can greatly reduce computational complexity.
Technical scheme is as follows:
A kind of method of screening Radio Link multipath of low operand, step comprises:
(1) for antenna is provided with flag register, and set for the first time is 0 or 1;
(2) take out the highest multipath of energy from multipath to be selected set, check in the described flag register corresponding with this skew, reach d-1 position, the left and right sides according to sky wire size of the multipath of described taking-up and skew, d represents the minimum spacing of effective multipath; If the position of being checked is identical with the described set first time, show current multipath and the multipath selected between spacing meet the demands, described current multipath is effective multipath; If the position of being checked is inequality with the described set first time, show that current multipath and the multipath spacing of having selected do not meet the demands, and abandon described current multipath;
(3) select effective multipath after, in the flag register of described effective multipath correspondence, corresponding with the skew of described effective multipath position, and d-1 position, left and right sides set for the second time, set for the second time is opposite with set for the first time, promptly when set for the first time is 0, set for the second time is 1, and when the set first time was 1, set for the second time was 0.
Further, in the step (1), in multipath set to be selected, all multipaths are arranged according to energy order from high to low.
Further, in the step (2), determine the flag register of antenna according to the sky wire size of the multipath of described taking-up, according to the skew of the multipath of described taking-up, effectively the minimum spacing d of multipath takes out the corresponding position of this skew, reaches the pairing mask value in d-1 position, the left and right sides from described flag register; When the value of carrying out set for the first time for the flag register of antenna in the step (1) is 0, if the pairing mask value in position of described taking-up is not complete 0, then the spacing between the multipath of described taking-up and the effective multipath selected is less than minimum spacing d, abandon the multipath of this taking-up, from described multipath set to be selected, extract next multipath and continue to handle; If the pairing mask value in position of described taking-up is complete 0, then the spacing between the multipath of described taking-up and the effective multipath selected satisfies the requirement of minimum spacing d, and the multipath of this taking-up is effective multipath.
Further, in the step (2), after from described multipath set to be selected, taking out the highest multipath of energy, the multipath of the described taking-up of deletion from described multipath set to be selected.
Further, in the step (3), judge further whether described multipath set to be selected is empty, if described multipath set to be selected is sky, then screening operation is finished; Otherwise, in multipath set to be selected, extract the highest multipath of next energy, up to filtering out whole effective multipaths.
The cycle-index n total with conventional method
2/ 2 compare, and the inventive method has greatly reduced computational complexity, and especially when the multipath number was big, advantage was more obvious.The spent processor clock base of every multipath of the inventive method processing is originally stablized, and the increase with screened multipath number is not exponential variation, and needed clock number is few, has embodied the characteristics of low operand.
Embodiment
The inventive method is to guarantee that by inspection the spacing of multipath screens multipath, during more than or equal to 6, adopts method provided by the present invention to screen in multipath number to be screened, and can reduce operand greatly.
With reference to the accompanying drawings, the preferred embodiments of the present invention are done detailed description.
With reference to shown in Figure 1, the device of screening Radio Link multipath comprises that multipath collection modules, flag register are provided with module, flag register, choose module.
The multipath collection modules is used to store multipath, and multipath is marked with day wire size and skew, and multipath just sorts according to energy in the multipath collection modules.If desired, the multipath collection modules sorts according to the height of described multipath energy.
Flag register is provided with module and is used for corresponding flag register to antenna being set, and gives flag register set.After elected delivery piece was selected effective multipath, flag register was provided with the module position that handle is corresponding with skew in the flag register of multipath correspondence, reaches position, d-1 position, the left and right sides.
Choose module and be used for extracting the highest multipath of energy from the multipath collection modules, according in sky wire size of multipath and the skew checkmark register corresponding with skew, reach d-1 position, the left and right sides, d represents the minimum spacing of effective multipath; If selected bits is identical with set, show that the spacing between current multipath that extracts and the multipath of having selected meets the demands, current multipath is effective multipath; If selected bits and set are inequality, show that current multipath and the multipath spacing of having selected do not meet the demands, and abandon the current multipath that extracts.After choosing module and from the multipath collection modules, taking out the highest multipath of energy, from the multipath collection modules, delete the multipath that taken out and the parameter of mark thereof.
For convenience, suppose that the multipath number is n in the multipath set to be selected, spacing is more than or equal to d between the effective multipath on the same antenna in requirement, and symbol Fo (i) represents the skew of i multipath, and the skew valid value range is 0~m-1; The sky wire size of i multipath of symbol Fa (i) expression; The energy of i multipath of symbol Fe (i) expression; D represents the minimum spacing of effective multipath.
With reference to shown in Figure 2, for antenna 0,1 is provided with the flag register of a m position respectively, and clear 0.
From multipath to be selected set, take out the highest multipath of energy, in the flag register of correspondence, check, judge corresponding with skew, reach whether d-1 position, the left and right sides is 1 according to its day wire size, skew.
With reference to shown in Figure 3, if all positions are 0, show current multipath and all multipaths of having selected between spacing meet the demands, current multipath is effective multipath.
With reference to shown in Figure 4,, show that current multipath and the multipath spacing of having selected do not meet the demands, and abandon current multipath if any position is 1.
Certainly, also can when beginning, be set to complete 1 by the register of Fig. 2.With all be 1 show current multipath and all multipaths of having selected between spacing meet the demands; With any position is 0 to show that current multipath and the multipath spacing of having selected do not meet the demands.
With reference to shown in Figure 5, select effective multipath at every turn after, in the flag register of correspondence, position that need be corresponding, reach d-1 position, the left and right sides and be set to 1 with skew.
If when beginning Fig. 2 register be set to complete 1, then need be after selecting effective multipath at every turn, the corresponding position of skew, reach d-1 position, the left and right sides and be set to 0.
By above method, all multipaths in the reprocessing multipath set to be selected filter out whole effective multipaths.
Said method, total cycle-index are n, the number of multipath in the multipath set promptly to be selected, and the number of computational complexity and multipath is linear.
With reference to shown in Figure 6, the processing procedure of multipath screening is described further.
In the present embodiment, the flag register of the m position of antenna 0/1 is designated as gadwMaskAnt0[respectively], gadwMaskAnt1[], and before beginning to screen multipath, all clear 0.
All multipaths in the multipath set to be selected are according to energy sequence arrangement from high to low.Every multipath in the pair set, treatment step is as follows:
Step S601: clear 0 antenna, 0/1 pairing flag register.
At this, with register gadwMaskAnt0[] and gadwMaskAnt1[] clear 0.
Step S602: from multipath set to be selected, take out the highest multipath F (i) of energy, and from this multipath set to be selected, delete F (i).The energy of multipath to be selected is Fe (i), and a day wire size is Fa (i), and valid value range is antenna 0 or 1; Skew is Fo (i), and valid value range is 0~m-1.
Step S603: the flag register gadwMaskAnt0[that determines antenna 0/1 according to Fa (i)]/gadwMaskAnt1[].
According to the minimum spacing d of Fo (i) and effective multipath, from flag register, take out the pairing mask value in [Fo (i)-(d-1), Fo (i)+(d-1)] position.
Step S604: judge whether corresponding mask all is 0.
If all be 0, execution in step S605; Otherwise, execution in step S602.
If the pairing mask value of multipath F (i) is not complete 0, then the spacing between F (i) and the effective multipath selected abandons F (i) less than minimum spacing d, gets back to step S602 and continues to handle.
Step S605: if the pairing mask value of multipath F (i) is complete 0, then the spacing between F (i) and the effective multipath selected satisfies the requirement of minimum spacing d, and output F (i) is effective multipath.
Step S606: flag register gadwMaskAnt0[is set]/gadwMaskAnt1[] [Fo (i)-(d-1), Fo (i)+(d-1)] position be complete 1.
In the process of follow-up choosing footpath,, whether check promising 1 position by reading the mask of multipath to be selected in flag register, judge multipath to be selected and the multipath selected between spacing too little.
Step S607: judge whether multipath set to be selected is empty.
If multipath set to be selected is for empty, then screening operation is finished; Otherwise, get back to step S602 and continue to handle.
Below, choosing the operation dominant frequency is 32 bit processors of 100MHz, adopts conventional method and patented method to realize the screening of Radio Link multipath thereon respectively.
The multipath energy scope is 1~65536, and a day wire size is 0,1, and requiring the minimum spacing between the multipath is d=8, and the valid value range of multipath skew is 0~255 (m=256).Test from 1 to 64 of multipath number, and finish the needed processor clock number of multipath screening by two kinds of methods, test result is as shown in table 1.
Amount of calculation that table 1 patented method and conventional method need and optimization ratio
Test result can prove that this method has following advantage:
(1) amount of calculation linear increase with the increase of screened multipath number has overcome in the conventional method amount of calculation shortcoming that index increases with the increase of screened multipath number.
(2) the inventive method is handled every processor clock number that multipath is spent, and basicly stable about 75 clock, the increase with screened multipath number does not change, and needed clock number is few, has embodied the characteristics of low operand.
(3) during practical engineering application, the multipath number of multipath collection to be selected is generally between 16-32.
With reference to shown in Figure 7, the curve representation of top adopts the operand of conventional method and the corresponding relation of finger number, following curve representation adopts the operand of the inventive method and the corresponding relation of finger number, adopts the inventive method to be reduced to original 20%~40% to the amount of calculation of needs.
(4) at the multipath number when less (being less than 6), the inventive method is more than the processor clock number that conventional method needs.
Reason is that the inventive method needs to remove antenna 0,1 pairing flag register before beginning processing, its needed processor clock number is fixed, the variation with the multipath number does not change, and therefore needs in actual applications, treats with a certain discrimination at screened multipath number.During for multipath number less (less than 6), the conventional method of can sampling; When multipath number more (more than or equal to 6), adopt technical solution of the present invention to have remarkable advantages.