TECHNICAL FIELD

The disclosure relates to the field of communications, and more particularly to a method and device for sending a Sounding Reference Signal (SRS).

BACKGROUND

Radio frames in a Long Term Evolution (LTE) system may have frame structures in a Frequency Division Duplex (FDD) mode or a Time Division Duplex (TDD) mode.FIG. 1is a schematic diagram of a frame structure in an FDD mode according to the related art. As shown inFIG. 1, a 10-millisecond (ms) radio frame is formed by 20 slots numbered from 0 to 19, each having a length of 0.5 ms, and the slots 2i and 2i+1 form a subframe i with a length of 1 ms.FIG. 2is a schematic diagram of a frame structure in a TDD mode according to the related art. As shown inFIG. 2, a 10 ms radio frame is formed by two half frames, each having a length of 5 ms, each half frame includes 5 subframes, each having a length of 1 ms, and the subframe i is defined into two slots 2i and 2i+1, each having a length of 0.5 ms.

In the two frame structures, for normal Cyclic Prefixes (CPs), a slot includes 7 symbols with a length of 66.7 microseconds (us), wherein the CP length of the first symbol is 5.21 us, and the CP length of each of the other 6 symbols is 4.69 us; and for extended CPs, a slot includes 6 symbols, and the CP length of each of the symbols is 16.67 us. A time unit Tsis defined to be Ts=1/(15,000×2,048) seconds, and supported Uplink (UL)/Downlink (DL) configurations are shown in Table 1. For each subframe in a radio frame, “D” represents a subframe dedicated to downlink (DL) transmission, “U” represents a subframe dedicated to uplink (UL) transmission, and “S” represents special subframes for three domains, i.e., a Downlink Pilot Time Slot (DwPTS), a Guard Period (GP) and an Uplink Pilot Time Slot (UpPTS). Lengths of the DwPTS and the UpPTS are shown in Table 2, and a total length of the DwPTS, the GP and the UpPTS is 30,720·Ts=1 ms. Each subframe i is represented by two slots 2i and 2i+1, and a length of each slot is Tslot=15, 360·Ts=0.5 ms.

LTE TDD supports UL/DL switching periods of 5 ms and 10 ms. If a DL-to-UL switching point period is 5 ms, special subframes may exist in two half frames; and if the DL-to-UL switching point period is 10 ms, the special subframes may exist in the first half frame only. Subframe 0, subframe 5 and DwPTS are always configured for DL transmission UpPTS and subframe(s) immediately following the special subframes are dedicated to UL transmission.

Table 1 shows UL/DL configurations, as shown in Table 1; and

Table 2 shows special subframe configurations (DwPTS/GP/UpPTS length), as shown in Table 2.

TABLE 1DL-ULswitchingUL-DLpointSubframe numberconfigurationperiod012345678905msDSUUUDSUUU15msDSUUDDSUUD25msDSUDDDSUDD310msDSUUUDDDDD410msDSUUDDDDDD510msDSUDDDDDDD65msDSUUUDSUUD

TABLE 2Normal CP, DLExtended CP, DLSpecialUpPTSUpPTSsubframeNormalExtendedNormalExtendedconfigurationDwPTSCP, ULCP, ULDwPTSCP, ULCP, UL06,592 · Ts2,192 · Ts2,560 · Ts7,680 · Ts2,192 · Ts2,560 · Ts119,760 · Ts20,480 · Ts221,592 · Ts23,040 · Ts324,144 · Ts25,600 · Ts426,336 · Ts7,680 · Ts4,384 · Ts5,120 · Ts56,592 · Ts4,384 · Ts5,120 · Ts20,480 · Ts619,760 · Ts23,040 · Ts721,592 · Ts———824,144 · Ts———

In an LTE system, a Physical Downlink Control Channel (PDCCH) is used to carry UL and DL scheduling information and UL power control information. Downlink Control Information (DCI) formats are divided into DCI formats 0, 1, 1A, 1B, 1C, 1D, 2, 2A, 3, 3A and the like. An e-Node-B (eNB) may configure User Equipment (UE) through DCI, or the LE accepts configuration of higher layers, that is, the UE is configured through higher layer signaling.

Broadcast information of the LTE system is divided into a Master Information Block (MIB) and a System Information Block(s) (SIB). The MIB is transmitted on a Physical Broadcast Channel (PBCH), and the SIB(s) (also referred to as Scheduled Information (SI)) are transmitted on a Physical Downlink Shared Channel (PDSCH). According to different scheduling requirements (for example, periods), the SIB information is further divided into a plurality of pieces of SI for transmission, and the system supports at least four pieces of SI (i.e., SIB-1, SIB-2, SIB-3 and SIB-4).

An SRS is a signal between UE and an eNB for measuring Channel State Information (CSI). In the LTE system, UE regularly sends a UL SRS on the last data symbol of a sending subframe according to parameters indicated by an eNB, for example, bandwidth, frequency-domain location, sequence cyclic shift, period and subframe offset. The eNB judges UL CSI of the UE according to the received SRS and executes operations of frequency-domain selection scheduling, closed-loop power control and the like according to the obtained CSI.

In the same SRS bandwidth, multiple UEs may use different cyclic shifts on the same frequency comb and then send SRSs in a code division multiplexing manner, or two UEs may send SRSs on different frequency combs in a frequency division multiplexing manner. For example, in the LTE system, UEs sending SRSs in a certain SRS bandwidth (4 Resource Blocks (RBs)) may use 8 cyclic shifts and may use 2 frequency combs, so that there are totally 16 available resources for sending the SRSs for the UEs, that is, at most 16 SRSs may be sent at the same time in the SRS bandwidth. Since UL Single User Multiple Input Multiple Output (SU-MIMO) is not supported in the LTE system, there is only one antenna for a single UE to send SRSs at every time instant, and thus the UE requires only one SRS resource. Therefore, in the SRS bandwidth, the system may multiplex at most 16 UEs at the same time.

An LTE-Advanced (LTE-A) system is a next-generation evolved system of the LTE system, supports UL SU-MIMO and may use at most 4 antennae as UL transmitting antennae. That is, a single UE may send SRSs on multiple antennae at the same time, and an eNB may estimate a state on each channel according to the SRSs received on each antenna.

It is proposed in existing LTE-A researches that, non-precoded (namely antenna-specific) SRSs should be used in UL communication. At this moment, when a UE uses multiple antennae to send non-precoded SRSs, SRS resources required by the UE may be increased, and this inevitably reduces the number of UEs which may be multiplexed at the same time in the system. In addition, not only is periodic SRS sending in the original LTE system reserved, but also aperiodic SRS sending may be configured for the UE through DCI or higher layer signaling.

For example, in a certain SRS bandwidth (4 RBs), if each UE uses 4 antennae to send SRSs, the number of resources required by each UE is 4. According to the total SRS resource number 16 supported in the SRS bandwidth, the number of UEs which may be multiplexed in the SRS bandwidth is reduced to 4. The number of users that may be multiplexed at the same time in the system is ¼ of original LTE system. It is proposed in existing LTE-A release 10 researches that UE may send SRSs in two triggering manners, i.e., higher layer signaling (also referred to as triggering through a trigger type 0) or DCI (also referred to as triggering through a trigger type 1), periodic SRSs are triggered on the basis of the higher layer signaling and aperiodic SRSs are triggered on the basis of the DCI. In LTE-A release 10, an aperiodic SRS sending manner is added to improve an SRS resource utilization rate to a certain extent and improve resource scheduling flexibility.

In future LTE-A release 13 researches, in a scenario of configuring full-dimension-MIMO or massive-MIMO, along with increase of an SRS measurement requirement of TDD channel reciprocity and increase of the number of multiplexed users, it has become very unlikely for an existing SRS multiplexing capacity to meet the requirement.

A manner of adding a time-domain symbol (for example, an UpPTS) for sending an SRS is proposed in the related art. However, for how to send the SRS on the added time-domain symbol, there is yet no effective solution proposed at present.

For the problem in the related art that a technical solution of sending an SRS on a time-domain symbol is imperfect, there is yet no effective solution at present.

SUMMARY

Embodiments of the disclosure provide a method and device for sending an SRS, so as to at least solve the problem in the related art that a technical solution of sending an SRS on a time-domain symbol is imperfect.

According to an embodiment of the disclosure, an Method for sending an SRS is provided, which may include that:

UE sends an SRS to an eNB on a time-domain symbol of a special subframe, wherein the time-domain symbol may include one or more of time-domain symbols occupied by an UpPTS, and a number of the time-domain symbols occupied by the UpPTS may be N, where N may be an integer no less than 3 and no greater than 12.

Furthermore, the operation that the UE sends the SRS to the eNB on the special subframe may include that:

the UE sends the SRS to the eNB according to predefined configuration information, wherein the predefined configuration information may include at least one of the following: determining a time-domain symbol location for sending the SRS according to parity of a sequence number of a subframe n where an SRS triggering request detected by the UE is located; or determining the time-domain symbol location for sending the SRS according to a range of the subframe n where the SRS triggering request detected by the UE is located.

Furthermore, the operation of determining the time-domain symbol location for sending the SRS according to the parity of the sequence number of the subframe n where the SRS triggering request detected by the UE is located may include that:

when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is an odd number, it is predefined that the aperiodic SRS is sent on a newly added UpPTS or a UE-specific UpPTS of standard Release 13 (Rel-13) and later, and when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is an even number, it is predefined that the aperiodic SRS is sent on a conventional UpPTS; or,

when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is an even number, it is predefined that the aperiodic SRS is sent on the newly added UpPTS or the UE-specific UpPTS of standard Rel-13 and later, and when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is an odd number, it is predefined that the aperiodic SRS is sent on the conventional UpPTS,

wherein the conventional UpPTS may be an UpPTS occupying last two or last one time-domain symbol in the special subframe.

Furthermore, the operation of determining the time-domain symbol location for sending the SRS according to the range of the subframe n where the SRS triggering request detected by the UE is located may include that:

when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 0 or 1 or 3 or 4, it is predefined that the aperiodic SRS is sent on the newly added UpPTS or the UE-specific UpPTS of standard Rel-13 and later, and when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 5 or 6 or 8 or 9, it is predefined that the aperiodic SRS is sent on the conventional UpPTS; or,

when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 5 or 6 or 8 or 9, it is predefined that the aperiodic SRS is sent on the newly added UpPTS or the UE-specific UpPTS of standard Rel-13 and later, and when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 0 or 1 or 3 or 4, it is predefined that the aperiodic SRS is sent on the conventional UpPTS; or,

when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 3 or 4 or 8 or 9, it is predefined that the aperiodic SRS is sent on the newly added UpPTS or the UE-specific UpPTS of standard Rel-13 and later, and when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 0 or 1 or 5 or 6, it is predefined that the aperiodic SRS is sent on the conventional UpPTS,

wherein the conventional UpPTS may be the UpPTS occupying the last two or last one time-domain symbol in the special subframe.

Furthermore, the time-domain symbol location in the special subframe for sending the SRS by the UE may be related to at least one of the following parameters: the parity of the sequence number of the subframe n where the SRS triggering request detected by the UE is located, or an SRS sending period and subframe offset configuration of the UE.

Furthermore, before the operation that the UE sends the SRS to the eNB on the time-domain symbol of the special subframe, the method may further include that: the UE receives configuration information sent by the eNB, wherein the configuration information may include at least one of the following: the SRS sending period and subframe offset configuration of the UE, a corresponding relationship among a subframe index, an UpPTS index and a sending subframe index of the SRS, or indication information indicating a time-domain location for sending the SRS; and

the operation that the UE sends the SRS to the eNB on the special subframe may include that: the UE sends the SRS to the eNB according to the configuration information.

Furthermore, the SRS sending period and subframe offset configuration of the UE may include at least one of the following:

an SRS sending period value of the UE is 2 and an SRS subframe offset value is 0 and 1;

the SRS sending period value of the UE is 2 and the SRS subframe offset value is 0 and 2;

the SRS sending period value of the UE is 2 and the SRS subframe offset value is 0 and 3;

the SRS sending period value of the UE is 2 and the SRS subframe offset value is 1 and 2;

the SRS sending period value of the UE is 2 and the SRS subframe offset value is 1 and 3;

the SRS sending period value of the UE is 2 and the SRS subframe offset value is 2 and 3;

the SRS sending period value of the UE is 1 or 2 and the SRS subframe offset value is 0, 1 and 2;

the SRS sending period value of the LE is 1 or 2 and the SRS subframe offset value is 0, 1 and 3;

the SRS sending period value of the UE is 1 or 2 and the SRS subframe offset value is 0, 2 and 3;

the SRS sending period value of the UE is 1 or 2 and the SRS subframe offset value is 1, 2 and 3; or

the SRS sending period value of the UE is 1 or 2 and the SRS subframe offset value is 0, 1, 2 and 3.

Furthermore, the corresponding relationship among the subframe index, the UpPTS index and the sending subframe index of the SRS may include at least one of the following:

when the subframe index is 1 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 0;

when the subframe index is 1 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 1;

when the subframe index is 1 and is the third time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 2;

when the subframe index is 1 and is the fourth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 3;

when the subframe index is 6 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 4;

when the subframe index is 6 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 5;

when the subframe index is 6 and is the third time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 6; or

when the subframe index is 6 and is the fourth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 7.

Furthermore, the corresponding relationship among the subframe index, the UpPTS index and the sending subframe index of the SRS may include at least one of the following:

when the subframe index is 1 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 2;

when the subframe index is 1 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 3;

when the subframe index is 6 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 6; or

when the subframe index is 6 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 7.

Furthermore, the corresponding relationship among the subframe index, the UpPTS index and the sending subframe index of the SRS may include at least one of the following:

when the subframe index is 1 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 0;

when the subframe index is 1 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 1;

when the subframe index is 1 and is the third time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 2;

when the subframe index is 1 and is the fourth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 3;

when the subframe index is 1 and is the fifth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 4:

when the subframe index is 1 and is the sixth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 5;

when the subframe index is 6 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 6;

when the subframe index is 6 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 7;

when the subframe index is 6 and is the third time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 8;

when the subframe index is 6 and is the fourth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 9;

when the subframe index is 6 and is the fifth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 10; or

when the subframe index is 6 and is the sixth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 11.

Furthermore, the corresponding relationship among the subframe index, the UpPTS index and the sending subframe index of the SRS may include at least one of the following:

when the subframe index is 1 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 2;

when the subframe index is 1 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 3;

when the subframe index is 1 and is the third time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 4;

when the subframe index is 1 and is the fourth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 5;

when the subframe index is 6 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 8:

when the subframe index is 6 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 9;

when the subframe index is 6 and is the third time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 10; or

when the subframe index is 6 and is the fourth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 11.

Furthermore, the corresponding relationship among the subframe index, the UpPTS index and the sending subframe index of the SRS may include at least one of the following:

when the subframe index is 1 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 0;

when the subframe index is 1 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 1;

when the subframe index is 1 and is the third time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 2;

when the subframe index is 1 and is the fourth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 3;

when the subframe index is 6 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 5;

when the subframe index is 6 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 6;

when the subframe index is 6 and is the third time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 7; or

when the subframe index is 6 and is the fourth time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 8.

Furthermore, the corresponding relationship among the subframe index, the UpPTS index and the sending subframe index of the SRS may include at least one of the following:

when the subframe index is 1 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 2;

when the subframe index is 1 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 3;

when the subframe index is 6 and is the first time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 7; or

when the subframe index is 6 and is the second time-domain symbol occupied by the UpPTS, the sending subframe index of the SRS is 8.

Furthermore, when the SRS sending period is 1 or 2, the UE may send the SRS to the eNB on a subframe meeting the following relationship:
(A−B)mod4=0,
or, (A−B)mod5=0,
or, (A−B)mod6=0,
where mod may be a modulus operation function, A may represent the sending subframe index of the SRS and B may represent the SRS subframe offset value.

Furthermore, the eNB may indicate the time-domain symbol location for sending the SRS through Radio Resource Control (RRC) signaling, or, may indicate the time-domain symbol location for sending the SRS through DL control signaling.

Furthermore, when the SRS sending period M is shorter than 5 ms, the SRS sending period M may represent that M SRS sending resources are configured in a half radio frame, or may represent that M SRS sending resources are configured in a newly added UpPTS of a special subframe of the half radio frame.

According to another embodiment of the disclosure, an Device for sending an SRS is provided, which may be applied to UE and include:

a sending module, arranged to send an SRS to an eNB on a time-domain symbol of a special subframe, wherein the time-domain symbol may include one or more of time-domain symbols occupied by an UpPTS, and a number of the time-domain symbols occupied by the UpPTS may be N, wherein N may be an integer no less than 3 and no greater than 12.

Furthermore, the device may further include:

a configuration module, arranged to, before the SRS is sent to the eNB on the time-domain symbol of the special subframe, receive configuration information sent by the eNB, wherein the configuration information may include at least one of the following: an SRS sending period and subframe offset configuration of the UE, a corresponding relationship among a subframe index, an UpPTS index and a sending subframe index of the SRS, or indication information indicating a time-domain location for sending the SRS; and

the sending module may be arranged to send the SRS to the eNB according to the configuration information.

Furthermore, the sending module may be arranged to send the SRS to the eNB according to predefined configuration information, wherein the predefined configuration information may include at least one of the following: determining a time-domain symbol location for sending the SRS according to parity of a sequence number of a subframe n where an SRS triggering request detected by the UE is located; and determining the time-domain symbol location for sending the SRS according to a range of the subframe n where the SRS triggering request detected by the UE is located.

Furthermore, the sending module may include one of the following:

a first sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is an odd number, predefine that the aperiodic SRS is sent on a newly added UpPTS or a UE-specific UpPTS of standard Rel-13 and later;

a second sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is an even number, predefine that the aperiodic SRS is sent on a conventional UpPTS;

a third sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is an even number, predefine that the aperiodic SRS is sent on the newly added UpPTS or the UE-specific UpPTS of standard Rel-13 and later; and

a fourth sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is an odd number, predefine that the aperiodic SRS is sent on the conventional UpPTS.

Furthermore, the sending module may further include one of the following:

a fifth sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 0 or 1 or 3 or 4, predefine that the aperiodic SRS is sent on the newly added UpPTS or the UE-specific UpPTS of standard Rel-13 and later;

a sixth sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 5 or 6 or 8 or 9, predefine that the aperiodic SRS is sent on the conventional UpPTS;

a seventh sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 5 or 6 or 8 or 9, predefine that the aperiodic SRS is sent on the newly added UpPTS or the UE-specific UpPTS of standard Rel-13 and later;

an eighth sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 0 or 1 or 3 or 4, predefine that the aperiodic SRS is sent on the conventional UpPTS;

a ninth sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 3 or 4 or 8 or 9, predefine that the aperiodic SRS is sent on the newly added UpPTS or the UE-specific UpPTS of standard Rel-13 and later; and

a tenth sending unit, arranged to, when the sequence number of the subframe n where the SRS triggering request detected by the UE is located is 0 or 1 or 5 or 6, predefine that the aperiodic SRS is sent on the conventional UpPTS.

In the embodiments of the disclosure, a computer storage medium is further provided, which may store executable instructions which, when being executed, implement the Method for sending an SRS in the abovementioned embodiment.

According to the embodiments of the disclosure, the UE sends the SRS to the eNB on the time-domain symbol of the special subframe, wherein the time-domain symbol includes the one or more of the time-domain symbols occupied by the UpPTS, and the number of the time-domain symbols occupied by the UpPTS is N, wherein N is an integer no less than 3 and no greater than 12. The problem that a technical solution of sending an SRS on a time-domain symbol is imperfect is solved, and sending of the SRS on the added time-domain symbol is implemented.

