WO2011095009A1

WO2011095009A1 - Method and system for transmitting sounding reference signals

Info

Publication number: WO2011095009A1
Application number: PCT/CN2010/077040
Authority: WO
Inventors: 王瑜新; 戴博; 郝鹏; 梁春丽; 喻斌; 朱鹏; 张禹强
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-02-08
Filing date: 2010-09-17
Publication date: 2011-08-11
Also published as: CN101795145A; CN101795145B

Abstract

Provided in the present invention are a method and a system for transmitting Sounding Reference Signals. The method includes the following steps: a terminal receives indication information sent from a base station; and the terminal transmits a first Sounding Reference Signal (SRS) and a second SRS to the base station at the same time on two Orthogonal Frequency Division Multiplexing (OFDM) symbols in a sub-frame indicated in the indication information respectively. With the invention, the quantity of users that could be contained in an LTE-A system is increased.

Description

The present invention relates to the field of communications, and in particular, to a method and system for transmitting a Sounding Reference Signal (SRS). The uplink physical channel of the Long Term Evolution (LTE) system includes a Physical Random Access Channel (PRACH), and a Physical Uplink Shared Channel (PUSCH). Physical Uplink Control Channel (PUCCH for short). Among them, PUSCH has two different Cyclic Prefix (CP) lengths, which are Normal Cyclic Prefix (Normal CP) and Extended Cyclic Prefix (Extended Cyclic Prefix). Each sub-frame of a PUSCH consists of two slots (Slots). For different cyclic prefix lengths, the position of the Demodulation Reference Signal (DMRS) in the subframe will not be located. Similarly, FIG. 1 is a schematic diagram of a time domain position of a demodulation reference signal according to the prior art. As shown in FIG. 1, each subframe contains two DMRS symbols, where FIG. 1(a) is a schematic diagram of the DMRS time domain position when a normal cyclic prefix is used, and each subframe contains 14 orthogonal frequency division multiplexing ( Orthogonal Frequency Division Multiplexing (OFDM) symbol, including DMRS symbol, OFDM symbol represents the time domain position of one subframe, and Figure 1 (b) is a schematic diagram of i or position of DMRS when using extended cyclic prefix, each subframe Contains 12 or OFDM symbols. In LTE, the physical downlink control channel PDCCH is used for 7-load uplink and downlink scheduling information, and uplink power control information. The Downlink Control Information (DCI) format is divided into DCI formats 0, 1, 1A, 1B, 1C, 1D, 2, 2A, 3, 3A, and so on. The base station (e-Node-B, referred to as eNB for short) may configure a terminal device (User Equipment, UE for short) through downlink control information, or the terminal device accepts a higher layer configuration, which is also configured by high layer signaling. UE.

SRS is a signal used between a terminal device and a base station to measure Channel State Information (CSI). In a long term evolution system, the UE is instructed by the eNB. Parameters such as bandwidth, frequency domain position, sequence cyclic shift, period and subframe offset, and timing send the uplink SRS on the last data symbol of the transmission subframe. The eNB determines the uplink CSI of the UE according to the received SRS, and performs operations such as frequency domain selection scheduling, closed loop power control, and the like according to the obtained CSI. In the LTE system, the SRS sequence transmitted by the UE is obtained by cyclically shifting a root sequence ^v (") in the time domain. By performing different cyclic shifts on the same root sequence, different SRS sequences can be obtained, and the obtained SRS sequences are orthogonal to each other. Therefore, these SRS sequences can be allocated to different UEs to implement the UE. Between the CDMA system, the SRS sequence defines eight cyclic shifts α, given by the following formula (1): = 2π-^-

8 Equation (1) where ⁿ Rs is indicated by 3 bit signaling, which are 0, 1, 2, 3, 4, 5, 6, and 7, respectively. That is to say, in the same time-frequency resource, the UE in the cell has 8 available code resources, and the eNB can configure up to 8 UEs to simultaneously send the SRS on the same time-frequency resource. Equation (1) can be considered as dividing the SRS sequence into 8 parts at equal intervals in the time domain, but since the SRS sequence length is a multiple of 12, the minimum length of the SRS sequence is 24. In the LTE system, the frequency domain bandwidth of the SRS is configured in a tree structure. Each SRS bandwidth configuration corresponds to a tree structure. The SRS bandwidth of the highest layer (or the first layer) (SRS-Bandwidth) corresponds to the maximum SRS bandwidth of the SRS bandwidth configuration, or SRS bandwidth. range. After calculating the SRS bandwidth of the base station according to the signaling indication of the base station, the UE determines the initial frequency domain position of the SRS to be sent according to the frequency domain location of the upper layer signaling sent by the eNB. 2 is a schematic diagram of a frequency domain initial position for transmitting a SRS by a UE that allocates different ^Wrrcs according to the prior art. As shown in FIG. 2, UEs allocated with different "e will transmit SRS in different areas of the SRS bandwidth of the cell, where UE1 is based on""^ =0 determines the initial position of the frequency at which the SRS is transmitted, and UE2 determines the initial position of the frequency at which the SRS is transmitted according to "RRc = ₃ ", and UE3 determines the initial position of the frequency at which the SRS is transmitted according to "^ = 4, and UE4 ^{relies on Wrrc.} =6 determines the initial position of the frequency at which the SRS is transmitted. The sequence used by the SRS is selected from the demodulation pilot sequence group, and the SRS bandwidth of the UE is 4 When a resource block (abbreviated as RB), a computer generated (Computer Generated) sequence is used; when the SRS bandwidth of the UE is greater than 4 RBs, a Zadoff-Chu sequence of a corresponding length is used. In addition, in the same SRS bandwidth, the sub-carriers of the SRS are placed at intervals, that is, the SRS is transmitted in a comb structure, and the number of frequency combs in the LTE system is 2 , also corresponds to the time domain repeat coefficient value (Repetition Factor, abbreviated as RPF) is 2. FIG. 3 is a schematic diagram of a comb structure of a prior art SRS. As shown in FIG. 3, when each UE transmits an SRS, only one of the two frequencies is used, and comb=0 or comb=l. In this way, the UE transmits the SRS using only subcarriers whose frequency domain index is even or odd according to the indication of the upper layer signaling of 1 bit. This comb structure allows more UEs to transmit SRS within the same SRS bandwidth. Within the same SRS bandwidth, multiple UEs can use different cyclic shifts on the same frequency, and then send SRS through code division multiplexing, or two UEs can be combed on different frequencies, through frequency division multiplexing. Send SRS. For example, in an LTE system, a UE that transmits an SRS within a certain SRS bandwidth (4 RBs) can use 8 cyclic shifts and 2 frequency combs that can be used, so the UE has a total of 16 A resource that can be used to send SRS, that is, up to 16 SRSs can be sent simultaneously within this SRS bandwidth. Since the Single User Multiple Input Multiple Output (SU-MI MO) is not supported in the LTE system, the UE can only send one SRS at each time, so only one UE needs one. SRS resources, therefore, within the above SRS bandwidth, the system can simultaneously multiplex up to 16 UEs. The LTE-Advanced (LTE-Advanced) system is a next-generation evolution system of the LTE system, supports SU-MIMO in the uplink, and can use up to four antennas as uplink transmitting antennas. That is, the UE can simultaneously transmit SRS on multiple antennas at the same time, and the eNB needs to estimate the state on each channel according to the SRS received on each antenna. In the existing LTE-A study, it is proposed that in uplink communication, non-pre-coded (ie antenna-specific) SRS should be used. At this time, when the UE transmits the non-precoded SRS by using multiple antennas, the SRS resources required by each UE are increased, which causes the number of UEs that can be simultaneously multiplexed in the system to decrease. In addition, in addition to the LTE legacy periodic transmission SRS, the UE may also be configured to transmit the SRS by aperiodic by using downlink control information or higher layer signaling. For example, within a certain SRS bandwidth (4 RBs), if each UE transmits SRS using 4 antennas, then the number of resources required for each UE is 4. According to the above, the total number of SRS resources that can be supported in one SRS bandwidth is 16, so that it can be reused within this SRS bandwidth. The number of UEs is reduced to four. The number of users that can be simultaneously multiplexed in the system will be 1/4 of the original LTE. In addition, due to the demand of LTE-A, the number of users that the LTE-A system can accommodate should be no less than the LTE system, so this requirement is in contradiction with the actual decrease in the number of users when the multi-antenna transmits SRS. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a transmission scheme for measuring a reference signal to at least solve the above problems. According to an aspect of the present invention, a method for transmitting a measurement reference signal is provided, including the steps of: receiving, by a terminal, indication information sent by a base station; and performing, by the terminal, two orthogonal frequency division multiplexing in one subframe indicated by the indication information The first measurement reference signal and the second measurement reference signal are simultaneously transmitted to the base station on the OFDM symbol. Preferably, the two OFDM symbols are two uplink demodulation reference signal symbols of the subframe. Preferably, the method further includes: the terminal transmitting the third measurement reference signal on the last OFDM symbol of the subframe indicated by the indication information while transmitting the first measurement reference signal and the second measurement reference signal. Preferably, the method further includes: when the periodic measurement reference signal and the aperiodic measurement reference signal are configured to be transmitted in the same subframe, the terminal only sends the aperiodic measurement reference signal, or the terminal simultaneously transmits the periodic measurement. Reference signal and aperiodic measurement reference signal. Preferably, the first measurement reference signal and the second measurement reference signal are code-multiplexed with two orthogonal demodulation reference signals of the terminal or other terminal by using an orthogonal mask, or with the terminal or other terminal Subframes Two OFDM symbols in other OFDM symbols are code division multiplexed with an orthogonal mask. Preferably, the orthogonal mask is: [+1, +1] or [+1, -1]. Preferably, the base station indicates, by signaling, an orthogonal mask used by the first measurement reference signal and the second measurement reference signal of the terminal. Preferably, the frequency domain transmission position of the first measurement reference signal and the second measurement reference signal is the same as the reference signal sequence used. Preferably, the transmission bandwidth of the first measurement reference signal and the second measurement reference signal, the cyclic displacement value used, and the frequency are the same.

Preferably, the first measurement reference signal and the second measurement reference signal are capable of using a cyclic shift value of 8, 12 or 16. Preferably, the number of frequency combs that can be used by the first measurement reference signal and the second measurement reference signal is two, three or four. Preferably, before the terminal receives the indication information sent by the base station, the method further includes: the base station configuring the terminal to send the time domain location of the measurement reference signal, and sending the indication information to the terminal, where the time domain location is two orthogonal frequencies of the subframe The last OFDM symbol of the OFDM symbol and/or subframe is divided and multiplexed. Preferably, the indication information is indicated by downlink control information or higher layer signaling. According to another aspect of the present invention, a transmission system for measuring a reference signal is provided, including a base station and a terminal, where the base station includes: a first sending module, configured to send indication information to the terminal, where the indication information is used to indicate that the terminal sends Measure a time domain position of the reference signal; the terminal includes: a receiving module, configured to receive the indication information; and a second sending module, configured to respectively perform two orthogonal frequency division multiplexing OFDM symbols in one subframe indicated by the indication information The base station simultaneously transmits the first measurement reference signal and the second measurement reference signal. Preferably, the base station further includes: a configuration module, configured to configure a time domain location at which the terminal sends the measurement reference signal. Preferably, the configuration module is configured to configure a time domain location where the two uplink demodulation reference signal symbols of the subframe are located, where the terminal sends the time domain location of the first measurement reference signal and the second measurement reference signal, where the indication information is used to indicate Whether to transmit the measurement reference signal in the time domain position where the two uplink demodulation reference signal symbols of the subframe are located, or the indication information is used to indicate the time domain position where the two uplink demodulation reference signal symbols are located. Preferably, the second sending module is further configured to send the third measurement reference signal on the last OFDM symbol of the subframe indicated by the indication information while transmitting the first measurement reference signal and the second measurement reference signal. According to the present invention, the terminal respectively transmits the first measurement reference signal and the second measurement reference signal to the base station simultaneously on the OFDM symbols in the two time domains in one subframe indicated by the indication information sent by the base station, thereby solving the present situation. In the LTE-A system of the prior art, the problem of a decrease in the number of users when multiple antennas transmit SRS increases the number of SRS resources available in the LTE-A system, and increases the number of users that can be accommodated in the LTE-A system. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a schematic diagram of a time domain position of a demodulation reference signal in the prior art; FIG. 2 is a schematic diagram of a frequency domain initial position of a prior art UE transmitting SRSs with different "e"; FIG. 4 is a block diagram showing a structure of a transmitting system of an SRS according to an embodiment of the present invention; FIG. 5 is a block diagram showing a preferred structure of a transmitting system of an SRS according to an embodiment of the present invention; A flowchart of a method for transmitting an SRS according to an embodiment of the present invention; FIG. 7 is a flowchart 1 of a method for transmitting a preferred SRS according to an embodiment of the present invention; FIG. 8 is a preferred embodiment of the present invention. Flowchart 2 of the method for transmitting SRS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings in conjunction with the embodiments. It is to be noted that the embodiments and examples in the present application, without conflict The features in the present invention can be combined with each other. In the embodiment of the present invention, the contradiction between the LTE-A demand for user capacity and the decrease in the number of users when multiple antennas transmit SRS is solved by increasing the SRS resources available in the system. A SRS transmission system is provided, including a base station and a terminal. Figure 4 is a structural block diagram of a SRS transmission system according to an embodiment of the present invention. As shown in Figure 4, the base station includes: a first sending module 44, the terminal includes: receiving Module 46, second transmitting module 48, the system will be described in detail below. The base station includes: a first sending module 44, configured to send the indication information to the terminal, where the indication information is indicated by the downlink control information or the high layer signaling, where the indication information is used to indicate the time domain location of the SRS sent by the terminal. The terminal includes: a receiving module 46, configured to receive the indication information; the second sending module 48 is coupled to the receiving module 46, where the module is configured to respectively perform two orthogonal frequency division multiplexing OFDM symbols in one subframe indicated by the indication information Up, the first SRS (Measurement Reference Signal 1) and the second SRS (Measurement Reference Signal 2) are simultaneously transmitted to the base station. FIG. 5 is a block diagram of a preferred structure of a SRS transmission system according to an embodiment of the present invention. As shown in FIG. 5, the base station further includes a configuration module 42 configured to configure a time domain location in which the terminal transmits the SRS. Preferably, the configuration module 42 can configure whether the matching terminal sends the measurement reference signal in a time domain position where two uplink demodulation reference signal symbols of one subframe are located. At this time, the indication information may directly indicate the time domain position where the two uplink demodulation reference signal symbols are located, or may also indicate whether to transmit the measurement reference signal in the time domain position where the two uplink demodulation reference signal symbols are located. Preferably, the second sending module 48 is further configured to send the third SRS in a time domain location where the last data symbol of the subframe indicated by the indication information is located while transmitting the first SRS and the second SRS. In the embodiment of the present invention, a method for transmitting an SRS is provided corresponding to the foregoing system, and FIG. 6 is a flowchart of a method for transmitting an SRS according to an embodiment of the present invention. As shown in FIG. 6, the process includes The following steps are as follows: Step S602: The terminal receives the indication information sent by the base station. Step S604: The terminal separately sends the first measurement reference signal and the second measurement reference signal to the base station on the two OFDM symbols in one subframe indicated by the indication information. Through the above system and steps S602 to S604, the number of measurement reference signal resources in the LTE-A system is effectively increased. FIG. 7 is a flowchart 1 of a method for transmitting a preferred SRS according to an embodiment of the present invention. As shown in FIG. 7, the method includes the following steps: Step S702: A terminal receives indication information (for example, signaling) sent by a base station. [Instruction); Step S704, the terminal respectively demodulates the two uplink demodulation references in one subframe indicated by the indication information At the time domain location where the signal symbol is located, the first SRS and the second SRS are simultaneously transmitted to the base station. Preferably, in order to make the number of SRS resources in the system more, the flow in FIG. 8 can also be used. FIG. 8 is a flowchart of a preferred SRS sending method according to an embodiment of the present invention, as shown in FIG. The difference from the flowchart of FIG. 7 and FIG. 6 is that, in step S804, the terminal sends the third SRS on the last OFDM symbol of the subframe indicated by the indication information while transmitting the first SRS and the second SRS. . Preferably, before the step S502 and the step S602, the base station may configure the terminal to send the time domain location of the measurement reference signal, where the time domain location may be the last symbol of the subframe and/or two OFDM symbols of the subframe (for example, The time domain location where the two DMRS symbols are located. Preferably, the reference signal 1 and the measurement reference signal 2 are measured with two of the terminal or other terminal

The DMRS symbol is code division multiplexed with an orthogonal mask. Preferably, the orthogonal mask used may be [+1, +1] or [+1, -1]. Preferably, the orthogonal mask used to measure the reference signal 1 and the measurement reference signal 2 is [+1, -1]; or, the orthogonal mask used by the measurement reference signal 1 and the measurement reference signal 2 is indicated by signaling. . Preferably, the frequency domain transmission position of the measurement reference signal 1 and the measurement reference signal 2 is the same as the reference signal sequence used. Preferably, the transmission bandwidth of the measurement reference signal 1 and the measurement reference signal 2, the cyclic shift value used, and the frequency comb are the same. Preferably, the measurement reference signal 1 and the measurement reference signal 2 can be used with 8 cyclic shifts.

12 or 16 and the number of combs that can be used is 2, 3 or 4. Preferably, in a case where the periodic measurement reference signal and the aperiodic measurement reference signal are configured to be transmitted in the same subframe, the terminal may only transmit the aperiodic measurement reference signal, or the terminal may simultaneously transmit the periodic measurement reference. Signal and aperiodic measurement reference signals. The following preferred embodiments incorporate the technical solutions of the above-described embodiments and their respective preferred embodiments. In an embodiment, the base station sends control information to the UE to instruct the UE to send the SRS. The control information may be downlink control information and/or high layer signaling, including: when sending the SRS The field location indication information, the transmission bandwidth, the cyclic shift index value, the value of the RPF, and the frequency used by the UE. The time domain location indication information of the SRS may be 1 bit, 2 bits, or 3 bits, and is used to indicate a time domain location where the UE sends the SRS, where the time domain location is a time domain location where the two uplink DMRS symbols are located; The bit index value is 3 bits or 4 bits, which is used to indicate the cyclic shift used by the UE when sending the SRS, and may be 8, 12 or 16; the RPF value is 1 bit or 2 bits, and the value may be 2 or 3 or 4; The frequency comb position used by the UE uses 1 bit or 2 bits, and the corresponding value ranges from 0 to 1 or 0 to 3, respectively.

The signaling indication of the base station of the UE transmits the measurement reference signal 1 and the measurement reference signal 2 simultaneously in the time domain position of the two uplink DMRS symbols of the transmission subframe, where the transmission bandwidth of the reference signal 1 and the measurement reference signal 2 are measured. The cyclic shift value used, the value of the RPF, and the frequency comb position used by the UE are the same. In another embodiment, the base station sends control information to the UE, where it is used to indicate that the UE sends the SRS, where the control information may be downlink control information and/or high layer signaling, including: sending time domain location indication information of the SRS, sending Bandwidth, cyclic shift index value, value of RPF, frequency υ position used by the UE. The time domain location indication information of the sending SRS may be 1 bit, 2 bits, or 3 bits, and is used to indicate a time domain location where the UE sends the SRS, where the time domain location is the time domain location and the last one where the two uplink DMRS symbols are located. The time domain position where the data symbol is located; the cyclic shift index value is 3 bits or 4 bits, which is used to indicate the cyclic shift used by the UE when transmitting the SRS, and the value may be 8, 12 or 16; the value of the RPF is 1 bit. Or 2 bits, the value may be 2 or 3 or 4; the frequency used by the UE is 1 bit or 2 bits, and the value ranges from 0 to 3.

The signaling of the UE base station indicates that the measurement reference signal 1, the measurement reference signal 2, and the measurement reference signal 3 are simultaneously transmitted in the time domain position of the two uplink DMRS symbols of the transmission subframe and the time domain position where the last data symbol is located. The measurement reference signal 1, the transmission bandwidth of the measurement reference signal 2 and the measurement reference signal 3, the cyclic shift value used, the value of the RPF, and the frequency comb position used by the UE are the same. In summary, the foregoing embodiment of the present invention solves the problem that the number of users decreases when multiple antennas transmit SRS in the LTE-A system in the prior art, and increases the number of SRS resources available in the LTE-A system, thereby improving the number of SRS resources available in the LTE-A system. The number of users that can be accommodated in the LTE-A system. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present invention are intended to be included within the scope of the present invention.

Claims

The method for transmitting a measurement reference signal is characterized in that it comprises the following steps:

Receiving, by the terminal, indication information sent by the base station;

The terminal simultaneously transmits the first measurement reference signal and the second measurement reference signal to the base station on two orthogonal frequency division multiplexing OFDM symbols in one subframe indicated by the indication information. The method according to claim 1, wherein the two OFDM symbols are two uplink demodulation reference signal symbols of the subframe. The method according to claim 1, further comprising: said terminal indicating said indication information while transmitting said first measurement reference signal and said second measurement reference signal A third measurement reference signal is transmitted on the last OFDM symbol of the subframe. The method according to claim 1, further comprising: in a case where the periodic measurement reference signal and the aperiodic measurement reference signal are configured to be transmitted in the same subframe, the terminal only transmits the aperiodic The reference signal is measured, or the terminal simultaneously transmits the measurement reference signal of the period and the aperiodic measurement reference signal. The method according to any one of claims 1 to 4, wherein the first measurement reference signal and the second measurement reference signal and the two uplink demodulation reference signals of the terminal or other terminal码 Orthogonal masking is used for code division multiplexing, or two orthogonal OFDM symbols in other OFDM symbols of the subframe or other terminal of the terminal or other terminal are code-multiplexed. The method according to claim 5, wherein the orthogonal mask is: [+1, +1] or [+1, -1]. The method according to claim 5, wherein the base station indicates, by signaling, an orthogonal mask used by the first measurement reference signal and the second measurement reference signal of the terminal. Method according to any one of claims 1 to 4, characterized in that the frequency domain transmission position of the first measurement reference signal and the second measurement reference signal and the reference signal used ^歹¹ J is the same.

The method according to any one of claims 1 to 4, wherein a transmission bandwidth of the first measurement reference signal and the second measurement reference signal, a cyclic shift value used, and a frequency are used. the same.

10. The method according to claim 9, wherein the first measurement reference signal and the second measurement reference signal are capable of using a cyclic shift value of 8, 12 or 16.

The method according to claim 9, wherein the number of frequency combs that can be used by the first measurement reference signal and the second measurement reference signal is two, three or four.

The method according to any one of claims 1 to 4, wherein before the terminal receives the indication information sent by the base station, the method further includes: configuring, by the base station, a time domain in which the terminal sends the measurement reference signal Positioning, and transmitting the indication information to the terminal, where the time domain location is two orthogonal frequency division multiplexing OFDM symbols of the subframe and/or a last OFDM symbol of the subframe.

The method according to any one of claims 1 to 4, wherein the indication information is indicated by downlink control information or higher layer signaling.

A transmission system for measuring a reference signal, comprising a base station and a terminal, wherein

The base station includes: a first sending module, configured to send indication information to the terminal, where the indication information is used to indicate that the terminal sends a time domain location of the measurement reference signal; the terminal includes: a receiving module, Receiving the indication information; the second sending module, configured to simultaneously send the first measurement reference signal and the first to the base station on two orthogonal frequency division multiplexing OFDM symbols in one subframe indicated by the indication information Two measurement reference signals.

The system according to claim 14, wherein the base station further comprises: a configuration module, configured to configure a time domain location at which the terminal sends the measurement reference signal.

The system according to claim 15, wherein the configuration module is configured to configure a time domain location where two uplink demodulation reference signal symbols of the subframe are located, and send, by the terminal, the first measurement. a time domain position of the reference signal and the second measurement reference signal, where the indication information is used to indicate whether the two uplink demodulation reference signal symbols of the subframe are located The measurement reference signal is sent at the domain location, or the indication information is used to indicate a time domain location where the two uplink demodulation reference signal symbols are located.

The system according to any one of claims 14 to 16, wherein the second sending module is further configured to transmit the first measurement reference signal and the second measurement reference signal while And transmitting, by the indication information, the third measurement reference signal on the last OFDM symbol of the subframe.