The sending method of measuring reference signals and system
Technical field
The present invention relates to the communications field, especially relate to the sending method and the system of a kind of measuring reference signals (SoundingReference Signal abbreviates SRS as).
Background technology
Long Term Evolution (Long Term Evolution, abbreviating LTE as) uplink physical channel of system comprises Physical Random Access Channel (Physical Random Access Channel, abbreviate PRACH as), Physical Uplink Shared Channel (Physical uplink shared channel, abbreviate PUSCH as), Physical Uplink Control Channel (Physical uplink controlchannel abbreviates PUCCH as).Wherein, PUSCH has two kinds of different Cyclic Prefix (Cyclic Prefix abbreviates CP as) length, is respectively general cyclic prefix (NormalCyclic Prefix, abbreviate Normal CP as) and extended cyclic prefix (Extended CyclicPrefix abbreviates Extended CP as).Each of PUSCH sends subframe (Subframe) and is made up of two time slots (Slot), for different circulating prefix-lengths, demodulated reference signal (Demodulation Reference Signal, abbreviating DMRS as) residing position can be different in subframe, and Fig. 1 is the time-domain position schematic diagram according to the demodulated reference signal of prior art.As shown in Figure 1, each subframe contains two DMRS symbols, wherein, Fig. 1 (a) is when adopting general cyclic prefix, the schematic diagram of DMRS time-domain position, each subframe contains 14 OFDMs (Orthogonal Frequency DivisionMultiplexing, abbreviate OFDM as) symbol, comprise the DMRS symbol, the time-domain position of a subframe of OFDM symbology, Fig. 1 (b) is when adopting extended cyclic prefix, the schematic diagram of DMRS time-domain position, and each subframe contains the OFDM symbol of 12 time domains.
In LTE, physical downlink control channel PDCCH is used to carry the uplink and downlink schedule information, and uplink power control information.Downlink Control Information (Downlink ControlInformation abbreviates DCI as) form (format) is divided into DCI format 0,1,1A, 1B, 1C, 1D, 2,2A, 3,3A etc.Downlink Control Information configurating terminal device (User Equipment abbreviates UE as) can be passed through in base station (e-Node-B abbreviates eNB as), and perhaps terminal equipment is accepted the configuration of high-rise (higher layers), is also referred to as by high-level signaling and comes configuration UE.
SRS is the signal that is used for measuring radio channel information (ChannelState Information abbreviates CSI as) between a kind of terminal equipment and base station.In long evolving system, UE regularly sends uplink SRS according to the parameters such as bandwidth, frequency domain position, sequence cyclic shift, cycle and sub-frame offset of eNB indication on last data symbol that sends subframe.ENB judges the up CSI of UE according to the SRS that receives, and carries out operations such as frequency domain selection scheduling, closed power control according to the CSI that obtains.In the LTE system, the SRS sequence that UE sends is by to the YITIAOGEN sequence
Carry out in time domain that cyclic shift α obtains.To carrying out different cyclic shift α with the YITIAOGEN sequence, just can access different SRS sequences, and mutually orthogonal between these SRS sequences that obtain, therefore, can use to different UE these SRS sequence allocation, to realize the code division multiple access between UE.In the LTE system, the SRS sequence definition 8 cyclic shift α, provide by following formula (1):
... formula (1)
Wherein, n
SRS CsSignaling by 3bit is indicated, and is respectively 0,1,2,3,4,5,6 and 7.That is to say that under same running time-frequency resource, the UE in the sub-district has 8 available sign indicating number resources, eNB can dispose 8 UE at most and send SRS simultaneously on identical running time-frequency resource.Formula (1) can be regarded as the SRS sequence uniformly-spaced is divided into 8 parts in time domain, but because the SRS sequence length is 12 multiple, so the minimum length of SRS sequence is 24.
In the LTE system, the frequency domain bandwidth of SRS adopts tree to be configured.The corresponding tree structure of each SRS band width configuration (SRS bandwidth configuration), the SRS bandwidth (SRS-Bandwidth) of top (or being called ground floor) is to maximum SRS bandwidth that should the SRS band width configuration, or is called the SRS bandwidth range.UE is according to the indication of the signaling of base station, calculate the SRS bandwidth of self after, the top signaling frequency domain position n that sends according to eNB again
RRCDetermine that self sends the frequency domain initial position of SRS.Fig. 2 is the different n of the distribution of prior art
RRCUE send the frequency domain initial position schematic diagram of SRS, as shown in Figure 2, distributed different n
RRCUE will send SRS in the zones of different of sub-district SRS bandwidth, wherein, UE1 is according to n
RRC=0 determines to send the frequency initial position of SRS, and UE2 is according to n
RRC=3 determine to send the frequency initial position of SRS, and UE3 is according to n
RRC=4 determine to send the frequency initial position of SRS, and UE4 is according to n
RRC=6 determine to send the frequency initial position of SRS.
The employed sequence of SRS is selected from the demodulation pilot frequency sequence group, and when the SRS of UE bandwidth was 4 Resource Block (Resource Block abbreviates RB as), using length was the sequence of the computer generation (Computer Generated abbreviates CG as) of 2 RB; When the SRS of UE bandwidth during, use the Zadoff-Chu sequence of corresponding length greater than 4 RB.
In addition, in same SRS bandwidth, the subcarrier of SRS (sub-carrier) is to place at interval, that is to say, pectinate texture is adopted in the transmission of SRS, the quantity of the frequency comb in the LTE system (frequency comb) is 2, and also the repeat factor value (RePetition Factor abbreviates RPF as) corresponding to time domain is 2.Fig. 3 is the pectinate texture schematic diagram of the SRS of prior art, as shown in Figure 3, when each UE sends SRS, only uses in two frequency comb, comb=0 or comb=1.Like this, UE only uses the frequency domain index to send SRS as the subcarrier of even number or odd number according to the indication of the top signaling of 1 bit.This pectinate texture allows more UE to send SRS in same SRS bandwidth.
In same SRS bandwidth, a plurality of UE can use different cyclic shifts on same frequency comb, send SRS by code division multiplexing then, also can two UE on different frequency comb, send SRS by frequency division multiplexing.For instance, in the LTE system, in certain SRS bandwidth (4 RB), send the UE of SRS, operable cyclic shift has 8, operable frequency comb is 2, and UE always has 16 resources that can be used to send SRS thus, that is to say, in this SRS bandwidth, can send 16 SRS simultaneously at most.Owing in the LTE system, do not support uplink single user multiple-input and multiple-output (Single User Multiple Input Multiple Output, abbreviate SU-MIMO as), UE constantly can only have an antenna transmission SRS at each, so a UE only needs a SRS resource, therefore, in above-mentioned SRS bandwidth, system is multiplexing 16 UE at most simultaneously.
Senior LTE (LTE-Advanced abbreviates LTE-A as) system is the evolution system of future generation of LTE system, at up support SU-MIMO, and can use 4 antennas as up transmitting antenna at most.That is to say that UE can send SRS simultaneously at synchronization on many antennas, and eNB need estimate state on every channel according to the SRS that receives on the every antenna.
In the research of existing LTE-A, propose: in uplink communication, should use the SRS of non-precoding (being that antenna is proprietary).At this moment, when UE used the SRS of the non-precoding of many antenna transmission, the needed SRS resource of each UE all can increase, and had also just caused in the system simultaneously multiplexing UE quantity to descend.In addition, send SRS, can also send SRS by Downlink Control Information or high-level signaling configuration UE aperiodic (aperiodic) except keeping LTE original cycle (periodic).
For example, in certain SRS bandwidth (4 RB), if each UE uses 4 antenna transmission SRS, each UE resource needed number is exactly 4 so.Be total up to 16 according to the SRS number of resources that can support in the above-mentioned SRS bandwidth, in this SRS bandwidth, UE number that can be multiplexing just is reduced to 4 so.Number of users that can be simultaneously multiplexing in the system will be 1/4 of original LTE.
Owing to propose in the demand of LTE-A, the number of users that the LTE-A system can hold should be no less than the LTE system again, so this demand just and the actual contradiction that caused that number of users descends during above-mentioned many antenna transmission SRS.
Summary of the invention
Main purpose of the present invention is to provide a kind of delivery plan of measuring reference signals, to address the above problem at least.
According to an aspect of the present invention, provide a kind of sending method of measuring reference signals, may further comprise the steps: terminal receives the indication information that the base station sends; And terminal sends first measuring reference signals and second measuring reference signals to the base station on two orthogonal frequency division multiplex OFDM symbols respectively simultaneously in a subframe of indication information indication.
Preferably, two two uplink demodulation reference signal symbols that the OFDM symbol is a subframe.
Preferably, said method also comprises: terminal sends the 3rd measuring reference signals on last OFDM symbol of the subframe that indication information is indicated when sending first measuring reference signals and second measuring reference signals.
Preferably, said method also comprises: measuring reference signals and aperiodic measuring reference signals in the cycle are configured under the situation of same subframe transmission, terminal only sends aperiodic measuring reference signals, perhaps, terminal sends the measuring reference signals and the aperiodic measuring reference signals in cycle simultaneously.
Preferably, two OFDM symbols in first measuring reference signals and second measuring reference signals and two uplink demodulation reference signals or other OFDM symbols of subframe adopt the quadrature masks to carry out code division multiplexing.
Preferably, the quadrature mask is: [+1 ,+1] or [+1 ,-1].
Preferably, the base station is by signaling indicating terminal first measuring reference signals and the employed quadrature mask of second measuring reference signals.
Preferably, the frequency domain of first measuring reference signals and second measuring reference signals sends the position, employed reference signal sequence is identical.
Preferably, the transmission bandwidth of first measuring reference signals and second measuring reference signals, employed cyclic shift value are identical with frequency comb.
Preferably, the cyclic shift value that can use of first measuring reference signals and second measuring reference signals has 8,12 or 16.
Preferably, the quantity of the frequency comb that can use of first measuring reference signals and second measuring reference signals is 2,3 or 4.
Preferably, receive in terminal before the indication information of base station transmission, above-mentionedly also comprise: the base station configuration terminal sends the time-domain position of measuring reference signals, and to terminal transmission indication information, wherein, time-domain position is two orthogonal frequency division multiplex OFDM symbols of subframe and/or last OFDM symbol of subframe.
Preferably, indication information is indicated by Downlink Control Information or high-level signaling.
According to a further aspect in the invention, provide a kind of transmitting system of measuring reference signals, comprised base station and terminal, this base station comprises: first sending module, be used for sending indication information to terminal, wherein, indication information is used for the time-domain position that indicating terminal sends measuring reference signals; This terminal comprises: receiver module is used to receive indication information; Second sending module is used for sending first measuring reference signals and second measuring reference signals simultaneously to the base station respectively on two orthogonal frequency division multiplex OFDM symbols of a subframe of indication information indication.
Preferably, the base station also comprises: configuration module is used for the time-domain position that configurating terminal sends measuring reference signals.
Preferably, the time-domain position that configuration module is used to dispose two uplink demodulation reference signal symbol places of subframe is the time-domain position that terminal sends first measuring reference signals and second measuring reference signals, wherein, indication information is used to indicate whether send measuring reference signals on the time-domain position at two uplink demodulation reference signal symbol places of subframe, and perhaps indication information is used to indicate the time-domain position at two uplink demodulation reference signal symbol places.
Preferably, second sending module also is used for sending the 3rd measuring reference signals on last OFDM symbol of the subframe that indication information is indicated when sending first measuring reference signals and second measuring reference signals.
By the present invention, on the OFDM symbol of two time domains in the subframe that the indication information that adopts terminal to send in the base station is respectively indicated, send first measuring reference signals and second measuring reference signals simultaneously to this base station, the problem that number of users descends when having solved many antenna transmission SRS in the LTE-A system of prior art, increase the quantity of SRS resource available in the LTE-A system, improved the number of users that can hold in the LTE-A system.
Description of drawings
Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:
Fig. 1 is the time-domain position schematic diagram of the demodulated reference signal of prior art;
Fig. 2 is the different n of the distribution of prior art
RRCUE send the frequency domain initial position schematic diagram of SRS;
Fig. 3 is the pectinate texture schematic diagram of the SRS of prior art;
Fig. 4 is the structured flowchart according to the transmitting system of the SRS of the embodiment of the invention;
Fig. 5 is the preferred structure block diagram according to the transmitting system of the SRS of the embodiment of the invention;
Fig. 6 is the flow chart according to the sending method of the SRS of the embodiment of the invention;
Fig. 7 is the flow chart one according to the sending method of the preferred SRS of the embodiment of the invention;
Fig. 8 is the flowchart 2 according to the sending method of the preferred SRS of the embodiment of the invention.
Embodiment
Hereinafter will describe the present invention with reference to the accompanying drawings and in conjunction with the embodiments in detail.Need to prove that under the situation of not conflicting, embodiment and the feature among the embodiment among the application can make up mutually.
Contradiction between number of users descends when in embodiments of the present invention, solving LTE-A for the demand of user capacity and many antenna transmission SRS by SRS resource available in the increase system.Based on this, the transmitting system of a kind of SRS is provided, comprise base station and terminal.Fig. 4 is the structured flowchart according to the transmitting system of the SRS of the embodiment of the invention, and as shown in Figure 4, the base station comprises: first sending module 44, terminal comprises: receiver module 46, second sending module 48 are described in detail this system below.
The base station comprises: first sending module 44, this module are used for sending indication information to terminal, and wherein, indication information can be indicated by Downlink Control Information or high-level signaling, and indication information is used for the time-domain position that indicating terminal sends SRS.
Terminal comprises: receiver module 46, and this module is used to receive indication information; Second sending module 48 is connected to receiver module 46, this module is used for respectively two the orthogonal frequency division multiplex OFDM symbols of a subframe in the indication information indication, sends a SRS (measuring reference signals 1) and the 2nd SRS (measuring reference signals 2) simultaneously to the base station.
Fig. 5 is the preferred structure block diagram according to the transmitting system of the SRS of the embodiment of the invention, and as shown in Figure 5, the base station also comprises configuration module 42, and this module is used for the time-domain position that configurating terminal sends SRS.
Preferably, this configuration module 42 can dispose terminal and whether send measuring reference signals on the time-domain position at two uplink demodulation reference signal symbol places of a subframe.At this moment, indication information can directly be indicated the time-domain position at two uplink demodulation reference signal symbol places, perhaps, also can indicate whether to send measuring reference signals on the time-domain position at these two uplink demodulation reference signal symbol places.
Preferably, second sending module 48 also is used for when sending a SRS and the 2nd SRS sending Three S's RS on the time-domain position at last data symbol place of the subframe of indication information indication.
In embodiments of the present invention, corresponding to above-mentioned system, provide the sending method of a kind of SRS, Fig. 6 is the flow chart according to the sending method of the SRS of the embodiment of the invention, and as shown in Figure 6, this flow process comprises the steps:
Step S602, terminal receives the indication information that the base station sends;
Step S604, terminal sends first measuring reference signals and second measuring reference signals to the base station on two OFDM symbols respectively simultaneously in a subframe of indication information indication.
To step S604, increased the quantity of measuring reference signals resource in the LTE-A system by said system and step S602 effectively.
Fig. 7 is the flow chart one according to the sending method of the preferred SRS of the embodiment of the invention, and as shown in Figure 7, this method comprises the steps:
Step S702, terminal receives the indication information (for example, signaling indication) that the base station sends;
Step S704, terminal on the time-domain position at two uplink demodulation reference signal symbol places of a subframe of this indication information indication, sends a SRS and the 2nd SRS to the base station respectively simultaneously.
Preferably, in order to make the more of SRS resource in the system, can also adopt the flow process among Fig. 8, Fig. 8 is the flow chart according to the sending method of the preferred SRS of the embodiment of the invention, as shown in Figure 8, this flow process and Fig. 7 and Fig. 6 difference are, in step S804, terminal sends Three S's RS on last OFDM symbol of the subframe that this indication information is indicated when sending a SRS and the 2nd SRS.
Preferably, before above-mentioned steps S502 and step S602, the base station can configurating terminal sends the time-domain position of measuring reference signals, and this time-domain position can be the time-domain position at last symbol of subframe and/or two OFDM symbols of subframe (for example, two DMRS symbols) place.
Preferably, measuring reference signals 1 and measuring reference signals 2 and two DMRS symbols adopt quadrature mask (Orthogonal Cover Code abbreviates OCC as) to carry out code division multiplexing.
Preferably, employed quadrature mask can be [+1 ,+1] or [+1 ,-1].
Preferably, measuring reference signals 1 and measuring reference signals 2 employed quadrature masks are [+1 ,-1]; Perhaps, by signaling indication measurement reference signal 1 and measuring reference signals 2 employed quadrature masks.
Preferably, the measuring reference signals 1 and the transmission bandwidth of measuring reference signals 2, employed cyclic shift value, frequency comb are identical.
Preferably, measuring reference signals 1 and measuring reference signals 2 spendable cyclic shifts have 8,12 or 16, and spendable frequency comb quantity is 2,3 or 4.
Below in conjunction with preferred embodiment present embodiment is described in detail.
Preferred embodiment one
The base station sends control information to UE, is used to indicate UE to send SRS.Wherein, control information can be Downlink Control Information and/or high-level signaling, comprising: the time-domain position indication information, transmission bandwidth, cyclic shift index value, the value of RPF, the employed frequency comb of the UE position that send SRS.
Wherein, the time-domain position indication information that sends SRS can be 1 bit, 2 bits or 3 bits, is used to indicate UE to send the time-domain position of SRS, and this time-domain position is the time-domain position at two up DMRS symbol places; The cyclic shift index value is 3 bits or 4 bits, employed cyclic shift when being used to indicate UE to send SRS, and value can be 8,12 or 16; The value of RPF is 1 bit or 2 bits, and value can be 2 or 3 or 4; 1 bit or 2 bits are adopted in the employed frequency comb of UE position, and Dui Ying span is 0 to 1 or 0 to 3 respectively.
UE is according to the signaling indication of base station, on two up DMRS symbol time-domain positions that send subframe, send measuring reference signals 1 and measuring reference signals 2 simultaneously, wherein, the measuring reference signals 1 and the transmission bandwidth of measuring reference signals 2, employed cyclic shift value, the value of RPF, the employed frequency comb of UE position are identical.
Preferred embodiment two
The base station sends control information to UE, be used to indicate UE to send SRS, wherein, this control information can for Downlink Control Information and or high-level signaling, comprising: send SRS the time-domain position indication information, send bandwidth, cyclic shift index value, the value of RPF, the employed frequency comb of UE position.
Wherein, the time-domain position indication information that sends SRS can be 1 bit, 2 bits or 3 bits, be used to indicate UE to send the time-domain position of SRS, this time-domain position is the time-domain position at two up DMRS symbol places and the time-domain position at last data symbol place; The cyclic shift index value is 3 bits or 4 bits, employed cyclic shift when being used to indicate UE to send SRS, and value can be 8,12 or 16; The value of RPF is 1 bit or 2 bits, and value can be 2 or 3 or 4; 1 bit or 2 bits are adopted in the employed frequency comb of UE position, and span is 0 to 3.
UE sends measuring reference signals 1, measuring reference signals 2 and measuring reference signals 3 according to the signaling indication of base station simultaneously on the time-domain position at two up DMRS symbol time-domain positions that send subframe and last data symbol place.Wherein, the transmission bandwidth of measuring reference signals 1, measuring reference signals 2 and measuring reference signals 3, employed cyclic shift value, the value of RPF, the employed frequency comb of UE position are identical.
In sum, pass through the above embodiment of the present invention, the problem that number of users descends when having solved many antenna transmission SRS in the LTE-A system of prior art has increased the quantity of SRS resource available in the LTE-A system, has improved the number of users that can hold in the LTE-A system.
Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with the general calculation device, they can concentrate on the single calculation element, perhaps be distributed on the network that a plurality of calculation element forms, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in the storage device and carry out by calculation element, and in some cases, can carry out step shown or that describe with the order that is different from herein, perhaps they are made into each integrated circuit modules respectively, perhaps a plurality of modules in them or step are made into the single integrated circuit module and realize.Like this, the present invention is not restricted to any specific hardware and software combination.
The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.