A kind of indicating means of control channel transformat and system
Technical field
The present invention relates to a kind of indication technology of transformat, relate in particular to a kind of indicating means and system of control channel transformat.
Background technology
In 2G, 3G wireless communication system, because control channel adopts the constant transmissions form, therefore, for guaranteeing the quality of control channel, wireless communication system can normally be moved, when the design control channel, need to consider multiple composite factor, often to design, cause the waste of channel resource according to worst case.Such as, for cell mobile communication systems, the control channel of design must ensure the coverage rate of base station node B signal, making base station signal decline very big Cell Edge User also can be correctly detected.
In order to guarantee the quality of edge customer received signal, when the design control channel, for default modulation system, coded system, these transmission parameters of transmitting power, must adopt lower modulation system, lower chnnel coding code check or higher transmitting power.If control signaling total amount is less, this channel resource loss is can be uncared-for, and control channel adopts the constant transmissions form can make processing procedure simple, reduces the requirement to the hardware handles ability of equipment in the wireless communication system.
Yet, along with development of Communication Technique, wireless communication system becomes increasingly complex, the quantity of control signaling increases greatly, control channel still adopts constant transmissions form control channel, must cause the channel resource loss serious, and efficiency of transmission is low, need adopts multiple transformat to improve efficiency of transmission control channel.In addition, the design means that is adopted in wireless communication system design also can cause control channel is adopted the demand of multiple transformat.Simultaneously, along with the development of integrated circuit technique, the hardware handles ability of equipment is more and more stronger in the wireless communication system, and it also is trend of the times that control channel is adopted multiple transformat.Wherein, cause adopting the design means of multiple transformat demand mainly to comprise two kinds of situations to control channel:
First kind of situation when the transmission parameter of wireless communication system changes, need be done corresponding adjustment to control channel.Such as, the variation that transmission parameter takes place can for: wireless communication system adopts time division duplex (TDD, when Time Division Duplex) mode is with support asymmetric data business, the variation of type of service in the variation of transmission bandwidth, the wireless communication system in the variation of uplink and downlink timeslot ratio, the wireless communication system.Second kind of situation adopts link adaptation techniques, makes full use of current control channel environment, mates control channel by conditioning signal transmission parameters adaptively, to improve the transmission performance and the efficient of control channel.Such as, the link adaptation techniques of employing is: adaptive coding and modulating (AMC) or through-put power control (TPC).Because both of these case all can make the control channel resource that needs constantly change, and therefore, need adopt multiple transformat to control channel, and the occupation condition of control channel is done corresponding adjustment, otherwise can cause the waste of channel resource.
At present, prior art adopts multiple transformat to be used to mate control channel to control channel, and adopts multiple transformat control channel and above-mentioned control channel to adopt the constant transmissions form to compare to control channel, can reduce taking channel resource.And, indicate the transformat of control channel by adopting control channel transformat indication (CCFI, Control Channel Format Indicator).
Long Term Evolution (LTE, Long Term Evolution) wireless communication system with the 3G wireless interface technology is the control channel that example is described every subframe.Present stage, the LTE wireless communication system can be supported two class frame structures: first kind frame structure as shown in Figure 1, both be applicable to the LTE wireless communication system that adopts Frequency Division Duplexing (FDD) (FDD, FrequencyDivision Duplex) mode, also be applicable to the LTE wireless communication system that adopts the TDD mode; The second class frame structure is only applicable to adopt the LTE wireless communication system of TDD mode as shown in Figure 2.And the system transmissions parameter is by Node B decision, and the business transmission of up-downgoing realizes by the NodeB scheduling.
Wherein, for the LTE wireless communication system that adopts the FDD mode, uplink/downlink control channel separates by frequency, exists simultaneously in time, the design of its every subframe control channel is simple relatively, and for example: the control channel of every subframe only need control this subframe and corresponding upstream or downstream subframe gets final product.FDD is at the frequency spectrum of supporting with voice can make full use of when being the symmetrical service of representative uplink/downlink control channel, but when carrying out being the asymmetrical data service of representative with IP, the utilance of frequency spectrum then greatly reduces, 60% when being about symmetrical service.
For FDD, adopt the advantage of the LTE wireless communication system of TDD mode to be: can support asymmetrical data service, uplink/downlink control channel to take identical frequency, take different time slot positions in time.As shown in Figure 2; the long radio frames of 10ms is divided into two fields; each field comprises 7 business time-slots; transmission up-downgoing targeting sequencing between time slot 0 and the time slot 1; and have protection at interval between descending pilot frequency and ascending pilot frequency, time slot 1 to time slot 6 can be by the position configuration up-downgoing transmission ratio transmission of up-downgoing switching point.Switching point position shown in the figure is between time slot 3 and time slot 4, and promptly time slot 1 is a uplink frame to time slot 3, and time slot 4 to time slot 6 passes downlink frame.The TDD communication network can be according to the actual conditions position of conversion up-downgoing switching point neatly, can improve the availability of frequency spectrum of transmission asymmetric data when professional effectively.Yet the difference of switching point position can cause the increase of every subframe control channel design complexities.
For example: for the control channel transmitting downlink control signal, if uplink and downlink timeslot ratio is 3: 4, descending time slot then is described more than ascending time slot, each descending sub frame only needs to transmit the ascending scheduling control signaling and the ACK control signaling of the scheduling control signaling of downlink of this frame, corresponding sub-frame of uplink.If uplink and downlink timeslot ratio is 6: 1, descending time slot then is described far fewer than ascending time slot, each descending sub frame not only needs to transmit the scheduling control signaling of downlink of this frame, also will transmit the ascending scheduling control signaling and the ACK control signaling of 6 sub-frame of uplink.
In sum, LTE wireless communication system in different ways, the design distinguished of every subframe control channel is very big, and is corresponding, and the indicating means of the CCFI that adopts of institute realization control channel transformat is difference also.Therefore, prior art all needs to set in advance and the corresponding CCFI of the control channel of this design at different wireless communication system design control channel.
Wherein, LTE wireless communication system in employing FDD mode is an example, in advance in She Ji the frame format, generally include 14 OFDMs (OFDM) symbol, preceding n OFDM symbol determining every descending sub frame is used to encapsulate descending control signaling and transmission, n=1,2 or 3 wherein, n are that integer means that the control signaling can not use 1 OFDM symbol with data mixing.11 remaining OFDM symbols are used for encapsulation of data, then adopt CCFI to realize that the indicating means of control channel transformat may further comprise the steps:
Step 101, the content that pre-sets CCFI in the sub-frame frame structure are n=1,2 or 3, are used for expression: in the frame format of current subframe, be used to encapsulate the number of the OFDM symbol of control signaling; Node B will control signaling and be encapsulated in the subframe, send to terminal.
Such as, the content of CCFI is n=2, represents in the frame format of current subframe, the number that is used to encapsulate the OFDM symbol of control signaling is 2, takies 2 OFDM character positions encapsulation control signalings that is:.
Step 102, terminal are obtained the content of the CCFI in the sub-frame frame structure, know the shared OFDM character position of current subframe control signaling, extract the control signaling, and carry out transfer of data according to the indicated resource location of control signaling.
The existing in prior technology shortcoming is: can not pre-set its corresponding CCFI at the transmission characteristic of different wireless communication system, especially can not be applicable to complicated wireless communication system.For example: if with the LTE wireless communication system of TDD mode, adopt with the identical CCFI indicating means of the LTE wireless communication system of FDD mode, can not be applicable to the possible uplink and downlink timeslot ratio configuring condition of institute.As shown in Figure 2, when uplink and downlink timeslot ratio configuration near 1 the time, n=1,2,3 can satisfy all application substantially; When uplink and downlink timeslot ratio is configured on 6 on 1 time or 52 times, that is: the uplink and downlink timeslot ratio configuration was much larger than 1 o'clock, even configuration n=3, the control signal resource also is not enough; When uplink and downlink timeslot ratio is configured on 1 on 6 times or 25 times, that is: the uplink and downlink timeslot ratio configuration is much smaller than 1 o'clock, and it is too high that the control signaling takies the ratio of total resources, causes the wasting of resources.
Further, if satisfy the transmission characteristic of different wireless communication system, the bit that then need pre-set CCFI is very long, because CCFI also needs to take the OFDM character position, therefore, the resource that causes taking control channel like this is many, the data of being transmitted are few, and the efficient of wireless communication system operation is low.
Summary of the invention
In view of this, main purpose of the present invention is to provide a kind of indicating means of control channel transformat, be applicable to the various wireless communication systems that adopt multiple transformat control channel, be particularly useful for complicated wireless communication system, can realize the transport format information indication of control channel simply efficiently.
Another object of the present invention is to provide a kind of indication mechanism of control channel transformat, can realize the transport format information indication of control channel simply efficiently.
For achieving the above object, technical scheme of the present invention is achieved in that
A kind of indicating means of control channel transformat pre-sets control channel transformat indication CCFI, and this method also comprises:
A, according to the transmission characteristic of current wireless communication system, extract the transmission parameter of described system, according to described CCFI and described transmission parameter, (CCFI θ) sets up mapping relations and determines the n value to utilize n=ψ;
Wherein, n is the concrete transport format information of the indicated control channel of described CCFI; θ is described transmission parameter;
B, after base station node B and terminal connect, Node B will control signaling according to described n value and be encapsulated into and send to terminal in the subframe, by the CCFI channel n value be sent to terminal simultaneously;
After C, terminal receive described subframe and described n value, know the concrete transport format information of described control signaling in described control channel according to the n value, and from described subframe, extract the control signaling, and carry out data read according to the indicated resource location of control signaling.
Wherein, described n is specially the value of the shared resource location of described control signaling that is used for determining that described subframe encapsulates;
Then among the step C, terminal is specifically known the shared resource location of described control signaling according to the n value.
Wherein, when described wireless communication system was the Long Term Evolution LTE system of 3G wireless interface technology, described n was the number that is used to encapsulate the orthogonal frequency division multiplex OFDM symbol of described control signaling in the described subframe;
Then among the step C, terminal is further known the OFDM character position that described control signaling is shared according to the n value.
Wherein, set up mapping relations described in the steps A and determine that the n value is specially:, the configuration correspondence table is set determines the n value, and described configuration correspondence table is stored in Node B side and end side respectively according to the corresponding relation between described CCFI and the described transmission parameter.
Wherein, described transmission parameter is determined when connecting by Node B and terminal receiving-transmitting sides.
A kind of indication mechanism of control channel transformat comprises: base station side is provided with unit, base station side extraction unit, unit, base station side transmitting element, end side receiving element and end side extraction unit are set up in the base station side mapping; Wherein,
Base station side is provided with the unit, is used to pre-set CCFI, and sends to base station side mapping and set up the unit;
The base station side extraction unit is used for the transmission characteristic according to the current wireless communication system, extracts the transmission parameter of wireless communication system, sends to the base station side mapping and sets up the unit;
The unit is set up in the base station side mapping, be used for basis and from base station side the CCFI that the unit obtains be set, and from the transmission parameter that the base station side extraction unit obtains, (CCFI θ) sets up mapping relations and determines the n value to utilize n=ψ; By the CCFI channel n value is sent to described end side receiving element; Wherein, n is the concrete transport format information of the indicated control channel of CCFI; θ is a transmission parameter;
The base station side transmitting element is used for sending to described end side receiving element with comprising according to the control signaling of n value encapsulation and the subframe of CCFI;
The end side receiving element is used to obtain described subframe and described n value, and sends to described end side extraction unit;
The end side extraction unit is used for knowing the concrete transport format information of described control signaling at described control channel according to the described n value of obtaining, and extracts the control signaling from described subframe.
Wherein, the mapping of described base station side is set up and is comprised in the unit module is set, and is used for the mapping relations of setting up are arranged to dispose correspondence table, determines the n value by the corresponding relation between described CCFI and the described transmission parameter;
Accordingly, the mapping of described base station side is set up the unit and also is used for described configuration correspondence table is sent to described end side receiving element.
Wherein, this system also comprises: base station side memory cell, end side memory cell;
And described base station side mapping is set up the unit and also is used for described configuration correspondence table is sent to described base station side memory cell; Accordingly, the base station side memory cell is used for receiving and storing described configuration correspondence table;
Described end side receiving element also is used for described configuration correspondence table is sent to described end side memory cell, and is corresponding, and the end side memory cell is used for receiving and storing described configuration correspondence table, and sends to described end side extraction unit; Then described end side extraction unit is further used for knowing the shared resource location of described control signaling, and extract the control signaling from described subframe according to described n value and the described configuration correspondence table obtained.
Prior art only relies on the CCFI that pre-sets, at the different CCFI of different wireless communication system design; Further, if satisfy the transmission characteristic of different wireless communication system, need pre-set the CCFI of very long bit.The present invention is different from prior art, in order to be applicable to the different wireless communication system that adopts multiple transformat control channel, adopts general CCFI mapping mode.Be specially: extract the transmission parameter of wireless communication system, and transmission parameter is combined with CCFI, set up the concrete transport format information that mapping relations are determined the indicated control channel of CCFI jointly.Thereby, take all factors into consideration performance and efficient that control channel is carried out, carrying out efficient and handling and obtain best balance between the complexity.Further, reduced the bit that pre-sets CCFI, thereby, the resource occupation of minimizing control channel, the data of being transmitted are many, the efficient height of wireless communication system operation.
Description of drawings
Fig. 1 is the structural representation of the first kind frame structure of LTE wireless communication system support;
Fig. 2 is the structural representation of the second class frame structure of LTE wireless communication system support;
Fig. 3 is the realization flow schematic diagram of the indicating means of prior art control channel transformat;
Fig. 4 is the realization flow schematic diagram of the inventive method principle;
Fig. 5 is the composition structural representation of system principle of the present invention.
Embodiment
Core concept of the present invention is: after extracting the transmission parameter of current wireless communication system, simplify the subclass of control channel transformat.In conjunction with the CCFI of current wireless communication system and the transmission parameter that extracts, set up mapping relations, determine the concrete transport format information of the indicated control channel of CCFI jointly.Adopt this general CCFI mapping mode to indicate the concrete transformat of control channel, be applicable to the various wireless communication systems that adopt multiple transformat control channel.
For making the purpose, technical solutions and advantages of the present invention clearer, by the following examples and with reference to accompanying drawing, the present invention is described in more detail.
For having multiple transmission parameter in the future broadband wireless communication systems, taking for the control channel of different channels resource, in theory, can know the transformat of control channel by the mode that the transformat indication combines with blind Detecting.So-called blind Detecting is meant does not carry out the transport format information indication, receiver is distinguished according to some inherent feature of control channel, and blind Detecting does not need extra indication information, but the processing procedure operand is big, higher to hardware requirement, generally be only applicable to the less occasion of control channel transformat.So-called form indication is meant the transformat of the transformat indication information indication control channel that definition is extra, and it handles simple, does not need blind Detecting, but needs extra resource.
The present invention takes all factors into consideration the pluses and minuses of blind Detecting and transformat indication, with less bit indicating section transport format information, by the definite transport format information of the concrete judgement of blind Detecting, can increase channel resource and reduce and do best balance between the operand.Transformat indicating means of the present invention based on principle be: 1. determine the set of total control channel transformat; 2. divide the subclass of control channel transformat according to some relevant system parameters; 3. utilize CCFI to indicate the content of each subclass.Wherein, described relevant system parameters can be for influencing the transmission parameter of system transmissions characteristic, and transmission parameter is not packaged in the frame structure of subframe, but inform the receiving-transmitting sides of communication by other modes.
Here,, should satisfy three conditions according to the subset division of system parameters: the 1. element number approximately equal of each subclass, preferably the same, CCFI can adopt identical bit number to indicate like this; 2. the extraction system parameter will be considered the element sum of each subclass and the complexity of blind Detecting, has both guaranteed that CCFI can indicate with less bit, and the complexity that also will control blind Detecting is in receivable scope; 3. the system parameters of Xuan Zeing is preferably that receiving-transmitting sides known, so need not extra message transmission.
The bit number of CCFI is determined to take all factors into consideration the sum of control channel transformat and the complexity of blind Detecting, does best choice between efficient and performance.Specifically, as shown in Figure 4, the indicating means of control channel transformat of the present invention comprises: pre-set CCFI, establish CCFI and be made up of the L bit, then CCFI can the configuration of corresponding indication N=2L kind control channel.
As shown in Figure 4, this method is further comprising the steps of:
Step 201, according to the transmission characteristic of current wireless communication system, extract the transmission parameter of system, according to CCFI and transmission parameter, (CCFI θ) sets up mapping relations and determines the n value to utilize n=ψ.Wherein, n is the concrete transport format information of the indicated control channel of CCFI; θ is a transmission parameter.
Wherein, transmission parameter is determined when connecting by Node B and terminal receiving-transmitting sides.
Here, the extraction of transmission parameter should be satisfied two basic principles: first basic principle according to the limited subset division of carrying out the control channel transformat of this transmission parameter energy, makes subclass satisfy three conditions of above-mentioned subset division; The second, it is in common knowledge that the transmission parameter of extraction is preferably receiving-transmitting sides, like this, need not to send this transmission parameter before sending CCFI.
For example, for for adopting TDD mode LTE wireless communication system, transmission parameter can be for the type of service of uplink and downlink timeslot ratio, transmission bandwidth or transmission etc.These transmission parameters are just determined when Node B and terminal receiving-transmitting sides connect, and do not need mutual this information again, and only certain subclass by CCFI indication control channel transformat gets final product.
Step 202, after base station node B and terminal connect, Node B will control signaling according to the n value and be encapsulated into and send to terminal in the subframe, by the CCFI channel n value be sent to terminal simultaneously.
After step 203, terminal receive subframe and n value, know the concrete transport format information of control signaling in control channel, from subframe, extract the control signaling, and carry out data read according to the indicated resource location of control signaling according to the n value.
Wherein, set up mapping relations in the step 201 and determine that the n value is specially:, a configuration correspondence table can be set determine the n value, and will dispose correspondence table and be stored in Node B side and end side respectively according to the corresponding relation between CCFI and the transmission parameter.
Here, when system design, just determined these mapping relations, and these mapping relations have been presented as a configuration correspondence table; And these mapping relations are known altogether for receiving-transmitting sides in communication, that is to say, such configuration correspondence table respectively is set in the receiving-transmitting sides both sides.Then in the concrete communication process of receiving-transmitting sides, after Node B and terminal connected, Node B just can determine the n value according to information such as transmission parameter and control signalling coding modulation systems by known configuration correspondence table.
At the configuration correspondence table, for instance, according to the second class frame structure as shown in Figure 2, for adopting TDD mode LTE wireless communication system, determine that control signaling transformat is the quaternary PSK modulation, encoder bit rate can select { 1/12 according to the control channel condition, 1/6,1/3,2/3}, totally four kinds of modulation coding modes.
Because uplink and downlink timeslot ratio is to influence the more factor of control channel transformat, therefore extract uplink and downlink timeslot ratio as transmission parameter, and this transmission parameter is when the LTE wireless communication system inserts, receiving-transmitting sides is just arranged when link establishment, in other words, be that both sides are in common knowledge, do not need the extraneous information notice.If CCFI length is 2 bits, under the different uplink and downlink timeslot ratio configuring conditions,, configuration correspondence table as shown in table 1 is set determines n according to the corresponding relation between CCFI and the uplink and downlink timeslot ratio.
The different CCFI that the representative of in the table 1 first row pre-sets indicate different control channels to take resource situation, the different uplink and downlink timeslot ratio configurations that the first row representative is extracted, i.e. n=ψ (CCFI, θ) the θ variable in, the two pairing n value that is.
The numeral of table 1 is different for the value that n under the different time-gap configuring condition is described only, and concrete numerical value should obtain according to optimizing application.
|
CCFI={00} |
CCFI={01} |
CCFI={10} |
CCFI={11} |
UL/DL=6/1 |
2 |
4 |
6 |
9 |
UL/DL=5/2 |
1 |
2 |
4 |
6 |
UL/DL=4/3 |
1 |
2 |
3 |
4 |
UL/DL=3/4 |
1 |
2 |
3 |
- |
UL/DL=2/5 |
0 |
1 |
2 |
- |
UL/DL=1/6 |
0 |
1 |
2 |
- |
Table 1
Wherein, when n is specially the value of the shared resource location of control signaling that is used for determining that subframe encapsulates, then in the step 203, terminal is specifically known according to n value and is controlled the shared resource location of signaling, extracts the control signaling from subframe.
When wireless communication system is the Long Term Evolution LTE system of 3G wireless interface technology, then n is further for being used to encapsulate the number of the orthogonal frequency division multiplex OFDM symbol of controlling signaling in the subframe, then in the step 203, terminal is further known the shared OFDM character position of control signaling according to the n value, extracts the control signaling from subframe.
As shown in Figure 5, a kind of indication mechanism of control channel transformat comprises: base station side is provided with unit 11, base station side extraction unit 12, unit 13, base station side transmitting element 14, end side receiving element 21 and end side extraction unit 22 are set up in the base station side mapping.And the empty frame among Fig. 5 is represented base station equipment and terminal side equipment respectively, constitutes system of the present invention by base station equipment and terminal side equipment.
Wherein, base station side is provided with unit 11, is used to pre-set CCFI, and sends to base station side mapping and set up unit 13; Base station side extraction unit 12 is used for the transmission characteristic according to the current wireless communication system, extracts the transmission parameter of wireless communication system, sends to the base station side mapping and sets up unit 13.Unit 13 is set up in the base station side mapping, be used for basis and from base station side the CCFI that unit 11 obtains be set, and from the transmission parameter that base station side extraction unit 12 obtains, (CCFI θ) sets up mapping relations and determines the n value to utilize n=ψ; By the CCFI channel n value is sent to end side receiving element 21; Wherein, n is the concrete transport format information of the indicated control channel of CCFI; θ is a transmission parameter.
Base station side transmitting element 14 is used for sending to end side receiving element 21 with comprising according to the control signaling of n value encapsulation and the subframe of CCFI.
End side receiving element 21 is used to obtain described subframe and described n value, and sends to end side extraction unit 22; End side extraction unit 22 is used for knowing the concrete transport format information of described control signaling at described control channel according to the described n value of obtaining, and extracts the control signaling from described subframe.
Base station side mapping is set up and is comprised in the unit 13 module is set: be used for the mapping relations of setting up are arranged to dispose correspondence table, determine the n value by the corresponding relation between described CCFI and the described transmission parameter; Accordingly, base station side mapping is set up unit 13 and also is used for described configuration correspondence table is sent to end side receiving element 21.
This system also comprises: base station side memory cell, end side memory cell; And the base station side mapping is set up unit 13 and also is used for described configuration correspondence table is sent to described base station side memory cell; Accordingly, the base station side memory cell is used for receiving and storing described configuration correspondence table.
End side receiving element 21 also is used for described configuration correspondence table is sent to described end side memory cell, and is corresponding, and the end side memory cell is used for receiving and storing described configuration correspondence table, and sends to end side extraction unit 22; Then the end side extraction unit 22, are further used for knowing the shared resource location of described control signaling, and extract the control signaling from described subframe according to described n value and the described configuration correspondence table obtained.
The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention.