Background technology
Long Term Evolution project (Long Term Evolution; LTE) system is based on the system of scheduling; The running time-frequency resource that is used to carry data by base station assigns; And running time-frequency resource information is handed down to the terminal through control channel, the terminal is according to the control channel information downlink data receiving of base station or send upstream data.
In the LTE system; Adopt the dynamic dispatching mode for common business; Be that send before downlink data or the reception upstream data each base station, the base station transmits control channel information to the terminal, and upstream data or downlink data receiving are sent in the terminal on the running time-frequency resource of this control channel information appointment.The LTE system be to need taking the fixedly particular traffic data bag of running time-frequency resource for a long time, the professional voice packets of VoIP etc. for example, and it is machine-processed to have introduced continuous dispatching.Continuous dispatching is meant the transformat that the base station fixes for fixing running time-frequency resource of certain professional allocation of packets and appointment, and packet sends with the regulation transformat in the allocated resource position, promptly on the predefine resource, sends with the predefine mode.Continuous dispatching is with respect to dynamic dispatching, and its difference is need not take the control channel resource, and advantage is to practice thrift the control signaling consumption.
The distribution of continuous dispatching cycle and resource need be decided by the business data packet characteristics that are scheduled.The business data packet that can carry out continuous dispatching all has the fixing and relatively-stationary characteristics of packet size of packet arrival cycle.The VoIP voice packets that with speed is 12.2kbit/s is an example, and the packet size behind its coding is 40byte basically, and the packet arrival cycle is fixed as 20ms.Therefore, the every resource that can transmit the 40byte data of distributing at a distance from 20ms so just can be when not taking the dispatch resource to the VoIP voice packets in the cycle in voice packets in the base station, the timely transmission of assurance VoIP voice packets.
The business data packet that need carry out continuous dispatching has different cyclophysises separately, and the arrival cycle that has is the integral multiple of 10ms, and professional like VoIP, the cycle is 20ms.The arrival cycle that has is not the integral multiple of 5ms or 10ms, as 15 frame/seconds, (frames per second, fps) or the video traffic of 30fps, its business data packet arrival cycle was respectively 32ms and 64ms.
In the prior art, in order to guarantee the timely transmission of business datum, the cycle of distributing for persistent scheduling resource equals the arrival cycle of business data packet, and the time point of continuous dispatching cycle appointment is the time location of service data transmission bag.This ascending-descending subframes of LTE FDD (FDD) is existed simultaneously; The system that the up-downgoing transmission is carried out simultaneously, this resource allocation cycle is no problem, but concerning LTE time division duplex (TDD) system; If resource allocation cycle is not the integral multiple in ascending-descending subframes transfer point cycle; Be the integral multiple of 5ms or 10ms, the predefine resource location that distributes by the business arrival cycle possibly be positioned on the subframe of different transmission directions, causes transfer of data normally not carry out.The frame structure of following brief account LTE TDD is so that be illustrated more clearly in this problem.
LTE TDD is a kind of tdd systems, and its frame structure is as shown in Figure 1, and each radio frames is made up of two fields (half-frame), and each field length is 5ms.Each field be divided into the conventional time slot that 8 length are 0.5ms (Time Slot, TS) with 1 special subframe that length is 1ms, per two conventional time slots are composed of a sub-frame, wherein the i sub-frame is made up of with 2i+1 time slot 2i.This special subframe is made up of descending pilot frequency time slot (DwPTS), protection time slot (GP) and uplink pilot time slot (UpPTS), and the length of DwPTS and UpPTS is configurable, and the total length of DwPTS, GP and UpPTS equals 1ms.Subframe 1 comprises DwPTS, GP and UpPTS with subframe 6.Wherein, subframe 0 is reserved as downlink transfer forever with subframe 5 and DwPTS.LTE TDD system supports the switching cycle of 5ms and 10ms.
Under 5ms switching cycle situation, UpPTS, subframe 2 and subframe 7 are reserved as uplink.Under 10ms switching cycle situation, DwPTS exists in two fields, but GP and UpPTS only exist in first field, and the DwPTS length in second field is 1ms.UpPTS and subframe 2 are reserved as uplink.
Difference according to the ascending-descending subframes transfer point; Can realize different ascending-descending subframes configurations, standard confirms that the ascending-descending subframes configuration of supporting is as shown in table 1 at present, wherein disposes 0~2nd, 5ms ascending-descending subframes transfer point; Configuration 3~6th, 10ms subframe transfer point; Letter D representes descending sub frame, and letter U is represented sub-frame of uplink, and alphabetical S representes special subframe.
Table 1
Based on the characteristics of LTE tdd frame structure, if the arrival cycle of business data packet is the integral multiple of radio frames length, the cycle professional like VoIP is 20ms, and its persistent scheduling resource is distributed as shown in Figure 2.Suppose that first packet sends at subframe X; Then the secondth, the 3rd, the 4th packet respectively need be in subframe (X+20) mod10, (X+40) mod10, the last transmission of (X+60) mod10; Promptly all on subframe X, send; Each continuous dispatching packet is the same position of corresponding radio frames all, and these subframes all are a direction certainly, promptly all is up or all is descending.Wherein mod10 representes 10 deliverys.
But arriving the cycle for business data packet be the situation of 10ms integral multiple, if according to business data packet arrival period allocated predefine resource then data direction can occur and the inconsistent situation of resource direction.With 32ms cycle business is example; What suppose the needs scheduling is downlink business; First packet sends at descending sub frame X; Then second, the 3rd, the 4th packet respectively need be in subframe (X+32) mod10, (X+64) mod10, the last transmission of (X+96) mod10, and these subframes are not necessarily descending sub frame.With the 1st kind of configuration mode (UL: DL=2UL: 2DL) shown in the table 1; X=0 (first packet sends in subframe 0) is an example, and second, the 3rd, the 4th subframe that data are responsible for assigning is respectively subframe 2,4,6, the table of comparisons 1; Subframe 2 is sub-frame of uplink; Impossible transmitting downlink data, subframe 6 is special subframes, whether can transmitting downlink data depend on that the length of DwPTS disposes.
This shows; Prior art arrives the period allocated persistent scheduling resource by business data packet; Replace the system that occurs for this ascending-descending subframes of LTE TDD; If it is not the integral multiple of radio frames that business data packet arrives the cycle, the subframe transmission direction of predefine resource location and the situation that the business datum direction is not inconsistent can appear, and finally cause transfer of data normally not carry out.
Embodiment
The direction of persistent scheduling resource is always identical, is up promptly or all, or all is descending.To be configured to equal the arrival cycle of business data packet in the prior art for the cycle that persistent scheduling resource is distributed simply; This arrival cycle is if the integral multiple of radio frames length; The always same subframe of the subframe of continuous dispatching in fact then can satisfy the needs of continuous dispatching; If but should not be the integral multiple of radio frames length in the arrival cycle, then the subframe of continuous dispatching will change, and the direction of continuous dispatching subframe may change in this case.The way that the present invention program takes is: periodically distribute the reference point of predefine resource, select the subframe consistent with professional transmission direction as the continuous dispatching subframe according to this reference point.
For making the object of the invention, technical scheme and advantage clearer, the present invention is done further to set forth in detail below in conjunction with specific embodiment.
The scheme of the embodiment of the invention one is with arrival cycle of business data packet reference point as resource allocation, persistent scheduling resource actual disposition nearest subframe consistent with professional transmission direction after time reference.Confirm to continue the configuration subframe in base station side and end side according to above-mentioned same mode.
As shown in Figure 3; Suppose that the business data packet arrival cycle is 32ms, ascending-descending subframes is configured to configuration 1 in the table 1, and (UL: DL=2UL: 2DL), the business data packet direction is descending; Suppose that in addition DwPTs can the bearing downlink data, promptly subframe 1 can the bearing downlink data with subframe 6.The corresponding subframe 0 of first reference point, this subframe is a descending sub frame, then business data packet 1 is sent at descending sub frame 0 in the base station.Second corresponding subframe 2 of reference point, but can know that according to allocation list this subframe is a sub-frame of uplink, first descending sub frame after the subframe 2 is a subframe 4, then business data packet 2 is sent in subframe 4 in the base station.The 3rd the corresponding subframe 6 of 4, the 4 reference points of the corresponding subframe of reference point, this two sub-frame all is a descending sub frame, so business data packet 3 and business data packet 4 are sent in subframe 4 and subframe 6 respectively in the base station.
Meanwhile, the terminal receives business data packet 1 at the corresponding descending sub frame 0 of first reference point.Second corresponding subframe 2 of reference point, but can know that according to allocation list this subframe is a sub-frame of uplink, first descending sub frame after the subframe 2 is a subframe 4, then the terminal receives business data packet 2 in subframe 4.The 3rd the corresponding subframe 6 of 4, the 4 reference points of the corresponding subframe of reference point, this two sub-frame all is a descending sub frame, so the terminal receives business data packet 3 and business data packet 4 in subframe 4 and subframe 6 respectively.
In said process, the base station is as the professional transmitting terminal of continuous dispatching, and the terminal is as the professional receiving terminal of continuous dispatching.If the continuous dispatching business is a uplink service, then transmitting terminal is the terminal, and receiving terminal is the base station.
Can find out that according to above concrete example of lifting the persistent scheduling resource period allocated flow process of the embodiment of the invention one is as shown in Figure 4, comprises the steps:
Step 401: the base station sends to the terminal with the persistent scheduling resource relevant information.Said persistent scheduling resource relevant information comprises the initial scheduling moment, frequency resource, Modulation and Coding Scheme (the Modulation and Coding Scheme of persistent scheduling resource; MCS), packet arrives cycle, packet sending direction (being up or descending).This persistent scheduling resource relevant information can periodically be sent in the base station.
Step 402: the packet arrival cycle that the transmitting terminal handle will send is point as a reference.
Step 403: the transmitting terminal of persistent scheduling resource judges whether current subframe direction is consistent with the data packet transmission direction, if then execution in step 404; Otherwise execution in step 405.When carrying out first, current subframe is the corresponding subframe of reference point.
Step 404: transmitting terminal sends this packet in current subframe, and goes to step 402.
Step 405: transmitting terminal as current subframe, and returns the next subframe of current subframe to execution in step 403.
For the receiving terminal of persistent scheduling resource, in 405, carry out the step corresponding respectively with step 402 to step 405 in transmitting terminal execution in step 402:
Step 402 ': the packet arrival cycle that the receiving terminal handle will receive is point as a reference.
Step 403 ': the receiving terminal of persistent scheduling resource judges whether current subframe direction is consistent with the data packet transmission direction, if, execution in step 404 ' then, otherwise execution in step 405 '.When carrying out first, current subframe is the corresponding subframe of reference point.
Step 404 ': receiving terminal receives this packet in current subframe, and goes to step 402 '.
Step 405 ': receiving terminal as current subframe, and returns the next subframe of current subframe to execution in step 403 '.
Because introduced the delay of predefine resource time location in the scheme of above-mentioned persistent scheduling resource, the resource conflict problem that possibly cause when need considering to dispose simultaneously a plurality of persistent scheduling resource.As shown in Figure 5, the subframe 0 of business 1 from the radio frames of System Frame Number (SFN)=0 begun to distribute the predefine resource by Fig. 3, frequency resource is f1; Professional 2 subframes 4 from the radio frames of SFN=3 are begun to distribute the persistent scheduling resource of same period, and frequency resource is f2.If f1=f2, the position of oval delineation in Fig. 1, distributing to professional 1 subframe two sub-frame of delaying time backward becomes subframe 4, and this is just identical with the running time-frequency resource of distributing to professional 2, the generation resource contention.
As a kind of preferred implementation, the base station needs to consider existing predefine resource occupation when distributing new predefine resource, guarantees that newly assigned resource does not overlap with occupied resource, so that solve the problem of resource contention.Occupied frequency resource need be got rid of in the base station in the embodiment of the invention when distributing persistent scheduling resource.A kind of simple way is the diverse frequency resource of frequency of choosing Yu having used.For each professional all identical situation of continuous dispatching cycle: can also carry out the operation that is described below:
Step 1: the transmission subframe T0 that confirms first packet of resource to be allocated according to the initial moment of business.First subframe should be consistent with the data packet transmission direction.
Step 2:, confirm to treat that the reference point and the peak excursion Tdelay of skew take place scheduling resource according to the ascending-descending subframes configuration of current use, the subframe numbers and the continuous dispatching cycle at first subframe place.To scheme Fig. 5 is example, and peak excursion is 2 sub-frame.
Step 3: get rid of the frequency resource that T0 has taken on the business data packet direction between the T0+Tdelay; If Tdelay is rightabout subframe, also to get rid of the frequency that the nearest subframe identical with the business data packet direction takies after the Tdelay (this subframe comprised postpone the predefine resource that disposes when resource periodic point and traffic direction are inconsistent).After getting rid of said frequencies, the residual frequency resource can be used as newly assigned predefine frequency resource.
The scheme of embodiment one is to handle to some persistent scheduling resource.When needs are dispatched a plurality of persistent scheduling resource simultaneously, the corresponding a plurality of reverse subframes continuously of continuous a plurality of reference point possibly appear, and persistent scheduling resource is deferred to the situation of the same subframe identical with traffic direction, causes resource allocation inhomogeneous.For example the configuration 1 in the table 1 is adopted in the ascending-descending subframes configuration, has two continuous dispatching business to be downlink business, and professional 1 and professional 2.The corresponding subframe 2 of professional 1 reference point, the corresponding subframe 3 of professional 2 reference points, and according to the ascending-descending subframes allocation list, subframe 2 is sub-frame of uplink with subframe 3, subframe 4 is a descending sub frame, then these two business all are deferred to subframe 4 and dispatch.
To this situation, can make overall arrangements to a plurality of persistent scheduling resource, set up the mapping relations table of reference point and the subframe consistent in advance with professional transmission direction; Find the subframe of reference point mapping according to said mapping relations table, with the subframe that is found as the continuous dispatching subframe.So just can avoid clashing.
The mode of setting up of mapping relations table can have multiple, lists two kinds of possible modes below:
Mode one:, reference point is being mapped to the corresponding subframe of reference point if the subframe of reference point correspondence is identical with professional transmission direction; If the subframe of reference point correspondence is opposite with professional transmission direction, in chronological sequence in proper order unmapped reference point is mapped to the subframe consistent with professional transmission direction in next radio frames.
The embodiment of the invention two has provided the solution of the persistent scheduling resource identical with mode one effect, and is as shown in Figure 6, comprises the steps:
Step 601: the base station sends to the terminal with the persistent scheduling resource relevant information.Said persistent scheduling resource relevant information comprises that the initial scheduling moment, frequency resource, MCS, the packet of persistent scheduling resource arrive cycle, packet sending direction (being up or descending).This persistent scheduling resource relevant information can periodically be sent in the base station.
Step 602: transmitting terminal arrives packet in cycle point as a reference, judges whether the corresponding subframe direction of reference point is consistent with the data packet transmission direction, if, then at this packet of subframe transmission of reference point correspondence; Otherwise, temporary this packet; For with this radio frames on all corresponding reference points of subframe all carry out aforesaid operations;
Step 603: transmitting terminal corresponds to temporary packet sequence on the subframe consistent with the data packet transmission direction on the next radio frames, and on these subframes, sends said packet successively.
For the receiving terminal of persistent scheduling resource, carry out simultaneously and step 602 and 603 corresponding steps:
Step 602 ': receiving terminal arrives packet in cycle point as a reference, and judges whether the corresponding subframe direction of reference point is consistent with the data packet transmission direction, if, then at this packet of subframe reception of reference point correspondence; Otherwise, this packet marking is reception; For with this radio frames on all corresponding reference points of subframe all carry out aforesaid operations;
Step 603 ': receiving terminal will be labeled as the packet sequence that does not receive and correspond on the subframe consistent with the data packet transmission direction on the next radio frames, and on these subframes, receive said packet successively.
Effect according to scheme persistent scheduling resource shown in Figure 6 is as shown in Figure 7.10 reference points are arranged on radio frames 0, and respectively corresponding subframe 0 is to subframe 9.For subframe 0 and subframe 1, its direction is consistent with the data packet transmission direction, so packet 0 sends on subframe 0 and subframe 1 respectively with packet 1; Subframe 2 is in the opposite direction with subframe 3 and data packet transmission, so packet 2 is kept in packet 3; Packet 4-6,9 afterwards sends on subframe 4-6 and subframe 9 respectively, and subframe 7 is also kept in subframe 8.Arrived radio frames 1, the subframe 2 of being kept in, subframe 3, subframe 7, subframe 8 are to send on subframe 0, subframe 1, subframe 4, the subframe 5 according to sequencing at the descending sub frame of radio frames 1.
The mode of setting up two of mapping relations table: reference point is mapped to the subframe identical with professional transmission direction according to the time order and function order.
Fig. 8 shows the solution that realizes the persistent scheduling resource that effect is identical with mode two, comprises the steps:
Step 801: the base station sends to the terminal with the persistent scheduling resource relevant information.Said persistent scheduling resource relevant information comprises that the initial scheduling moment, frequency resource, Modulation and Coding Scheme, the packet of persistent scheduling resource arrive cycle, packet sending direction (being up or descending).This persistent scheduling resource relevant information can periodically be sent in the base station.
Step 802: the data packet arrival cycle that the transmitting terminal handle of persistent scheduling resource will send is point as a reference.Step 802 is that circulation is carried out, and two packets that will send during adjacent twice execution in step 802 are temporal sequencing, and it is professional to belong to different continuous dispatching.
Step 803: the transmitting terminal of persistent scheduling resource judges whether current subframe direction is consistent with the data packet transmission direction, if then execution in step 804; Otherwise execution in step 805.When carrying out first, current subframe is the corresponding subframe of reference point.
Step 804: transmitting terminal sends this packet in current subframe, and goes to step 802.
Step 805: transmitting terminal as current subframe, and returns the next subframe of current subframe to execution in step 803.
Simultaneously, receiving terminal also to carry out with step 802 to 805 corresponding steps, repeat no more.
It is thus clear that flow process shown in Figure 8 and flow process shown in Figure 4 are very similar, particularly when having only a continuous dispatching professional, both are identical.In the flow process of Fig. 4, the packet that will send all be that corresponding same continuous dispatching is professional, if there are a plurality of continuous dispatching business so simultaneously, a plurality of packets then possibly occur and delay time and transmit in the same subframe; And in the flow process of Fig. 8, the packet that will send can to belong to different continuous dispatching professional, the adjacent data bag is temporal sequencing, so just can be so that the different pieces of information bag is distributed to different subframes.
Effect according to scheme persistent scheduling resource shown in Figure 8 is as shown in Figure 9.10 reference points are arranged on radio frames 0, and respectively corresponding subframe 0 is to subframe 9.For subframe 0 and subframe 1, its direction is consistent with the data packet transmission direction, so packet 0 sends on subframe 0 and subframe 1 respectively with packet 1; Subframe 2, subframe 3 is in the opposite direction with packet, so packet 2 is deferred on the subframe 4 and sends, and the reference point of packet 3 is revised as next subframe is subframe 5.After sending subframe 3 on the subframe 5, the reference point of packet 4 is set to subframe 6, and after sending subframe 4 on the subframe 6, the reference point of packet 5 is set to subframe 7.And subframe 7,8 and packet are in the opposite direction, so packet 5 is deferred to transmission on the subframe 9.The rest may be inferred, and the subframe 0 of radio frames 1, subframe 1, subframe 4 and subframe 5 are sent packet 6, packet 7, packet 8 and packet 9 respectively.
The embodiment of the invention also discloses a kind of persistent scheduling resource period allocated device, comprising:
Reference point is provided with module, is used to be provided with the reference point of resource allocation;
Select module, be used for the reference point that module is provided with being set and select the subframe consistent as the continuous dispatching subframe with professional transmission direction according to said reference point.
Preferably, said reference point is provided with module with arrival cycle of business data packet reference point as resource allocation.
Select module that two kinds of implementations specifically can be arranged.First kind of situation, said selection module comprises:
Judging unit is used to judge whether current subframe direction is consistent with the data packet transmission direction, if then send the signal of specifying current subframe to the unit is set; If inconsistent then with the next subframe of current subframe as current subframe and carry out above-mentioned decision operation; When carrying out first with the corresponding subframe of reference point as current subframe;
The unit is set, and the subframe that is used for said judging unit appointment is set to the continuous dispatching subframe.
In this case, newly assigned persistent scheduling resource possibly clash with the resource that existing business takies, and therefore, preferably, this device may further include:
Frequency is selected module, and the frequency resource that is used to select not to be used is carried the continuous dispatching business.
Second kind of situation, said selection module comprises:
Map unit is used to set up the mapping relations table of reference point and the subframe consistent with professional transmission direction;
Query unit is used for inquiring about according to current reference point the mapping relations table of said map unit, obtains corresponding subframe as the continuous dispatching subframe.
The above is merely preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of within spirit of the present invention and principle, being done, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.