HK1136702B - Method and device for transmitting srs signals in lte system - Google Patents

Description

Method and device for transmitting SRS signaling in LTE system

Technical Field

The present invention relates to a communication system, and more particularly, to a method and apparatus for transmitting an SRS in an LTE communication system.

Background

3GPP(The3^rdGenerationPartnerProject) standardization organization is making a new generation of wireless communication standards, which are named lte (longtermev). On the physical layer interface, the new standard adopts an ofdm (orthogonal frequency division multiplexing) technology different from the conventional cdma (code division multiplexing) technology, an OFDMA (orthogonal frequency division multiplexing) mode is adopted on the downlink, and SC-FDMA (single carrier-frequency division multiplexing access) is adopted on the uplink. The new standard technology can effectively resist multipath transmission, reduces the complexity of the traditional time domain equalization by adopting frequency domain equalization operation, and is more suitable for being applied to broadband high-speed data transmission.

The LTE standard technology can be divided into two types, namely tdd (time division duplex) and fdd (frequency division duplex), from an air interface, and an LTE system supports variable bandwidths, where the supported bandwidths include 1.4M, 3M, 5M, 10M, 15M, and 20MHz, and can meet the requirements of different scenarios. The physical layer frame structure of the LTEFDD system is shown as the first figure: the length of a radio frame (101) is 10ms, each radio frame is composed of 10 radio subframes (102), the duration of each radio subframe is 1ms, each radio subframe is composed of 2 slots (103), and the duration of each slot is 0.5 ms. The physical layer frame structure of the LTETDD system is shown in the second figure: the length of a radio frame (201) is 10ms, each radio frame is composed of 10 radio subframes (204), the duration of each radio subframe is 1ms, 5 consecutive radio subframes constitute a half frame (202), and the duration of the half frame is 5 ms. Unlike the lte fdd system, the 2(211) and 7 (212) th radio subframes in the lte tdd radio frame are 2 special subframes. The duration of the special subframe is 1ms, and is composed of 3 special slots, which are defined as DwPTS (205 or 208), GP (206 or 209), and UpPTS (207 or 210), respectively. The length of the DwPTS time slot, the GP time slot and the UpPTS time slot are variable and are configured by the system, and the total time length is equal to 1 ms. The UpPTS may consist of zero or 1 or 2 OFDM symbols. When the UpPTS is composed of 2 OFDM symbols, the UpPTS is used to transmit an uplink short random access channel (ShortRACH) or an SRS signal or to simultaneously transfer the ShortRACH channel and the SRS signal; when the length of the UpPTS is composed of 1 OFDM symbol, the UpPTS is used to transmit an uplink SRS signal. The other 8 subframes except for the 2 special subframes are each composed of 2 slots (203), and the time length of each slot is 0.5 ms.

In the LTE system, according to network scheduling, a UE (user equipment: UE) sends an SRS (sounding reference signal: monitoring reference signal) signal to an eNodeB (evolved node b: base station in the LTE system). The main roles of the SRS signal are: the eNodeB estimates the channel quality from the UE to the eNodeB link on the frequency band for transmitting the SRS by detecting the SRS signal, thereby carrying out frequency selective data scheduling; the eNodeB carries out timing tracking on the UE by receiving the SRS detection signal; and completing the closed loop power control. According to the developments standardized so far, the main conclusions of the lte fdd system regarding SRS transmission include: and broadcasting SRS signaling of a specified cell by the eNodeB according to the requirement, wherein the specified cell transmits the SRS in certain subframes with a certain period, and the period for transmitting the SRS is selected from {2, 5, 10, 20, 40, 80, 160, 320} ms. When the user equipment receives the SRS signaling of the designated cell, the OFDM symbol resources occupied by the SRS are not used when uplink data are transmitted. In order to complete the SRS function transmitted by the ue, the ue further needs to receive an SRS signaling sent by the network and specifying the ue, where the signaling indicates the ue to specifically transmit the SRS through the OFDM symbol resource used by the ue in the SRS transmission resource already dominated by the ue. Currently, in the physical layer design specifications already completed by LTE, no description of SRS signaling specifying a user equipment is transmitted. Currently, the basic understanding in the standard for SRS signaling for a given user is that the signaling includes 3 parts: duration (Duration), Period (Period), and Offset (Offset). Wherein the duration may be represented using 1 bit to indicate that it is only active once (onesinpshot) or that it is an unlimited time active (Infinite). Regarding the period, {2ms, 5ms, 10ms, 20ms, 40ms, 80ms, 160ms, 320ms } is currently selected from the following numbers. For LTEFDD, the offset parameter offset is the time between OFDM symbols of SRS transmission by a user from the beginning of the SRS period, and 1ms is used as the basic time unit; for LTETDD, the definition of the offset is different from LTEFDD, because LTETDD can transmit SRS signals in UpPTS or other conventional uplink subframes, because LTETDD uplink subframes may be discontinuous, and UpPTS also occupies at most 2 OFDM symbols, so in the LTETDD system, the parameter of the offset defines the position interval between a certain OFDM symbol position for transmitting SRS and the OFDM symbol position for transmitting SRS at the beginning of SRS transmission period. For example, if we define the SRS symbol position at the beginning of the period as 0, then a symbol position equal to 3 that can be used for transmitting SRS indicates that the two symbol positions are separated by 3, and there are at most 2 OFDM symbol positions in the middle that can be used for transmitting SRS signals.

The SRS transmission design in the lte tdd system is mainly consistent with the SRS transmission mechanism in the lte fdd system. However, the lte tdd system is different from the lte fdd system in structure, one of the differences is that the lte tdd system has both uplink subframes and downlink subframes in a 5ms half frame, and the number of the uplink subframes and the downlink subframes is configured by the network according to needs, and under some configurations, the minimum number of the uplink subframes in a 5ms half frame is only 1 (not including UpPTS), and according to the principle that one UE is allowed to transmit only once in one uplink subframe, SRS transmission is performed only once in a 5ms time interval, and SRS transmission in a 2ms period cannot be achieved, so that the performance of UE transmitting SRS in a fast time-varying channel is sacrificed.

Based on the difference between lte fdd and lte tdd, we find that the 2ms srs transmission period adopted in lte fdd system cannot be realized in lte tdd system according to the current design.

The patent proposes a new method and apparatus for transmitting SRS signaling in LTE system. By adopting the invention, the LTEFDD and LTETDD systems have SRS signaling with consistent formats, and meanwhile, the invention also solves the problem of how to support 2ms period in the LTETDD system.

Disclosure of Invention

The invention aims to provide a method and a device for transmitting SRS signals in an LTE communication system.

According to one aspect of the invention, a method for sending uplink SRS information by an LTE user terminal comprises the following steps:

a) a user terminal receives information N indicating SRS transmission;

b) the UE generates an SRS sequence;

c) if the information N indicates that the period for transmitting the SRS is two milliseconds, the user terminal transmits the SRS at 2 OFDM symbol positions in a half frame or a frame.

According to another aspect of the invention, an apparatus (406) for transmitting an SRS by an LTEUE comprises:

a module 401 for generating an SRS sequence;

a module 402, configured to receive SRS transmission information of a specified user;

a module 403, configured to receive other SRS transmission scheduling information;

a controller 404 for transmitting an SRS sequence;

a module 405 for adjusting the power factor.

According to another aspect of the present invention, a method for transmitting uplink SRS information by an LTE user terminal includes:

a) a user terminal receives information N indicating SRS transmission;

b) the UE generates an SRS sequence;

c) and according to the information N, one OFDM symbol is occupied in each period to transmit the SRS, or two OFDM symbols are occupied in each period to transmit the SRS.

Drawings

FIG. 1 is a schematic diagram of a frame structure of the LTEFDD;

fig. 2 is a schematic diagram of a frame structure of LTETDD;

FIG. 3 is a process diagram of an LTE system transmitting a user-specified SRS;

fig. 4 is a diagram of a process of transmitting SRS by the lte ue;

fig. 5 shows 7 uplink and downlink configurations of LTETDD;

FIG. 6 is example one;

fig. 7 is example two.

Detailed Description

For the lte fdd system, since the maximum SRS Period value range is {2, 5, 10, 20, 40, 80, 160, 320ms }, for maximum flexibility, the definition of the possible SRS Offset (Offset) for any Period value is to select {0, 1., Period-1} from the following values, and then, for the lte fdd, the SRS signaling for a specific user may consist of 2+5+10+20+40+80+160+320 — 637 indexes. This method provides flexibility to the maximum extent that 10 bits are needed to represent 637 indexes, and since 10 bits can represent 1024 information, 1024-637-387 indexes will be reserved for other purposes.

Since it may not be necessary to provide a maximum of 320 offsets when the period is 320ms, the above 10 bits are not necessarily the most reasonable, in which case the number of indexes can be correspondingly reduced according to the reduction of the offset range, and then the total required number of bits will be correspondingly reduced, and the number of indexes to be reserved will also be reduced.

UE receives index N which is transmitted from base station and indicates SRS period

For the lte tdd system, the SRS period is also selected from {2, 5, 10, 20, 40, 80, 160, 320ms }, wherein the offset parameters are designed the same as for lte fdd except for 2ms and 5ms periods. However, unlike the lte fdd, the uplink subframe of the lte tdd system does not always occur continuously, and thus a complete 2ms period cannot be found, and for this reason, the 2ms period of the lte tdd needs to be specially designed. Currently, there are 7 uplink and downlink configuration ratios supported by LTETDD, and referring to fig. 5(501-507), when defining the meaning of the SRS index of the designated user corresponding to the 2ms period, we define a group of corresponding SRS indexes to represent, for configurations 0(501), 1(502), 2(503), and 6(507), these indexes indicate that, in the 5ms half-frame period or one frame period, 2 consecutive OFDM positions or 2 arbitrary OFDM positions on the logical number are selected from OFDM symbols configured by the system for transmitting SRS, and notify the designated user to transmit SRS using these positions. With configurations 3(504), 4(505), and 5(506), the indexes indicate that 2 or arbitrary 2 OFDM positions in logical number are selected from OFDM symbols configured by the system for transmitting SRS in a 10ms frame period, and a specified user is notified to transmit SRS using these positions. Such a definition informs a designated user how to select the position of the OFDM symbol occupied by SRS transmission at a period of 2 ms. Considering that in the lte tdd system, there are 5 OFDM symbols available for transmitting SRS in a half frame of 5ms at most, the 5 symbols include two symbols of UpPTS and 3 OFDM symbols in normal subframes 2, 3, and 4. Therefore, if the selected symbol is any 2 symbols, there are C (5, 2) ═ 10(C denotes a combining operation) choices, and there are 10 indexes corresponding to the choices. Since 10 indices need to correspond one-to-one to a specific OFDM symbol doublet. The patent does not limit the specific corresponding relationship, and may be a randomly selected corresponding relationship, or may consider placing some indexes with high priority at a position closer to the front or the back of the comparison when selecting the corresponding relationship. One of the priority considerations is the case where 1 or 2 UpPTS symbols are included. If 2 consecutive available OFDM symbols are chosen, 4 cases (when the last OFDM symbol is not supported to be logically consecutive to the first OFDM symbol) or 5 cases (when the last OFDM symbol is supported to be logically consecutive to the first OFDM symbol) are needed for representation with 4 or 5 indices, respectively.

In the case of 5ms period, LTETDD has a special feature in that, for configurations 3(504), 4(505) and 5(506), there is no uplink physical resource in the second half frame of the 10ms frame, and therefore SRS cannot be transmitted in the second half frame, if only the first half frame selects 2 or any 2 OFDM positions in the logical number from the OFDM symbols configured for transmitting SRS in the system, and the specified user is informed to transmit SRS using these positions, this definition is the same as that of LTETDD2ms period, so in view of simplifying the system design, the 5ms period in our design is not applicable to LTETDD configurations 3, 4 and 5.

Comparing the LTETDD with the LTEFDD, the LTETDD cannot support a 2ms period and a 5ms period under some conditions, and further, the 2ms period and the 5ms period are redefined, so that a function similar to the LTEFDD is realized in the LTETDD.

Based on the redefining method, redefining a 2ms period configured with 0-2 and 6, wherein the actual period is 5ms, namely occupying two SRS symbols in every 5 ms; redefining the 2ms period of the configuration 3-5, the actual period is 10ms, that is, two SRS symbols are occupied in every 10 ms. Indeed, in a system configuration, the above-described concept of redefining the 2ms period and the 5ms period of the LTETDD may be applied to facilitate analogy with LTEFDD; it is also possible to directly define that two SRS symbols are configured within 5ms or 10ms without supporting 2ms period and 5ms period in some cases. The two methods are essentially the same. They are essentially the same as the method of periodic redefinition. For the latter method, specifically, the LTETDD system does not support an SRS period of 2ms, and for the configuration of 3-5, the SRS period of 5ms is not supported. However, it is supported that within each half frame, i.e., 5ms period, two SRS symbols are configured, e.g., for configuring 0-2 and 6; and supports configuring two SRS symbols in the first half frame of the radio frame, i.e. in the 10ms period, for example, for configuring 3-5. Here, two SRS symbols can be configured in each field using a similar method as described above when redefining the 2ms and 5ms periods, i.e. a fully flexible configuration method needs to indicate that C (5, 2) ═ 10(C denotes a combining operation) choices; or the configuration method is limited so as to reduce the number of selections, which is not limited by the present invention.

In addition, the redefinition of the 2ms period is to configure two SRS symbols in one half frame (with a length of 5ms), and equivalently, the lte tdd system may be defined to directly support the configuration of two SRS symbols in each half frame (with a length of 5ms) without supporting the 2ms period. Here, for configurations 0-2 and 6, the actual period is 5ms, i.e., two SRS symbols are occupied in every 5 ms; for the configuration 3-5, the actual period is 10ms, i.e. two SRS symbols are occupied in every 10 ms. Here, two SRS symbols can be configured in each field using a similar method as described above when redefining the 2ms and 5ms periods, i.e. a fully flexible configuration method needs to indicate that C (5, 2) ═ 10(C denotes a combining operation) choices; or the configuration method is limited so as to reduce the number of selections, which is not limited by the present invention.

The user equipment receives information N indicating SRS transmission from a network, and when the period value of the user SRS indicated by the N is less than or equal to the number of OFDM symbols which can transmit the SRS and are configured in the period of the whole cell, the offset is calculated by adopting the following method:

if N is in the range of 0 to 320/f-1 and the period indicated by N is 320 milliseconds, then transmitting the SRS with an offset of N f;

if N is between 320/f and 320/f +160/m-1, and the period indicated by N is 160ms, then the SRS is transmitted with an offset of (N-320/f) m;

if N is in the range of 320/f +160/m to 320/f +160/m +80/t-1, and the period indicated by N is 80 milliseconds, then transmitting the SRS with the offset of (N-320/f-160/m) x t;

if N is in the range of 320/f +160/m +80/t to 320/f +160/m +80/t +40/N-1, and the period indicated by N is 40ms, then the SRS is transmitted with an offset of (N-320/f-160/m-80/t) in;

if N is in the range of 320/f +160/m +80/t +40/N to 320/f +160/m +80/t +40/N +20/p-1, and the period indicated by N is 20 milliseconds, transmitting the SRS with the offset of (N-320/f-160/m-80/t-40/N) p;

if N is in the range of 320/f +160/m +80/t +40/N +20/p to 320/f +160/m +80/t +40/N +20/p +10/x-1, and the period indicated by N is 10 milliseconds, then the SRS is transmitted with the offset of (N-320/f-160/m-80/t-40/N-20/p) x;

if N is in the range of 320/f +160/m +80/t +40/N +20/p +10/x to 320/f +160/m +80/t +40/N +20/p +10/x +5-1, and the period indicated by N is 5 milliseconds, transmitting the SRS according to the offset of (N-320/f-160/m-80/t-40/N-20/p-10/x);

wherein f, m, t and n can take the values of 1, 2, 4 and 8; p can take the values of 1, 2, 4, 5 and 10; x can be 1, 2, 5; m represents the number of OFDM symbols which are configured in the period indicated by the information N and can transmit the SRS by the whole cell; f. the values of M, t, n and M need to be statically set in the system specification; "-" is the sign of subtraction.

The user equipment receives information N indicating SRS transmission from a network, and when the period value of the SRS of the designated user indicated by the N is larger than the number of OFDM symbols which can transmit the SRS and are configured in the period of the whole cell, the offset is calculated by adopting the following method:

if N is in the range of 0 to M-1, and the period indicated by N is 320 milliseconds, then the SRS is transmitted with an offset of N;

n is reserved by the system in the range of M to 320/f-1;

if N is from 320/f to 320/f + M-1, and the period indicated by N is 160 milliseconds, then the SRS is transmitted with the offset of N-320/f;

n is reserved by the system in the range of M to 320/f + 160/M-1;

if N is in the range of 320/f +160/M to M-1, and the period indicated by N is 80 milliseconds, then the SRS is transmitted with the offset of N-320/f-160/M;

n is reserved by the system in the range of M to 320/f +160/M + 80/t-1;

if N is in the range of 320/f +160/M +80/t to M-1, and the period indicated by N is 40 milliseconds, transmitting the SRS according to the offset of N-320/f-160/M-80/t;

n is reserved by the system in the range of M to 320/f +160/M +80/t + 40/N-1;

if N is in the range of 320/f +160/M +80/t +40/N to M-1, and the period indicated by N is 20 milliseconds, transmitting the SRS according to the offset of N-320/f-160/M-80/t-40/N;

n is reserved by the system in the range from M to 320/f +160/M +80/t +40/N + 20/p-1;

if N is in the range of 320/f +160/M +80/t +40/N +20/p to M-1, and the period indicated by N is 10 milliseconds, transmitting the SRS according to the offset of N-320/f-160/M-80/t-40/N-20/p;

n is reserved by the system in the range of M to 320/f +160/M +80/t +40/N +20/p + 10/x-1;

if N is in the range of 320/f +160/M +80/t +40/N +20/p +10/x to M-1, and the period indicated by N is 5 milliseconds, transmitting the SRS according to the offset of N-320/f-160/M-80/t-40/N-20/p-10/x;

n is reserved by the system in the range from M to 320/f +160/M +80/t +40/N +20/p +10/x + 5-1;

wherein f, m, t and n can take the values of 1, 2, 4 and 8; p can take the values of 1, 2, 4, 5 and 10; x can be 1, 2, 5; m represents the number of OFDM symbols which are configured in the period indicated by the information N and can transmit the SRS by the whole cell; f. the values of M, t, n and M need to be statically set in the system specification, "-" is the sign of subtraction.

The above design method is the most basic signaling design of the designated user SRS, the invention considers the signaling design method with consistent signaling formats of the lte fdd and the lte tdd, and the specific principle is as follows: first, the number of information bits occupied by SRS signaling transmission for a specific user to indicate lte fdd and lte tdd is the same, for example, both are 10 bits or 9 bits; second, regardless of LTEFDD or LTETDD, the set of index locations that are reserved in all indexes occupy one and only one segment of the contiguous index.

The SRS transmission signaling for a given user designed according to the principle that lte fdd is consistent with lte tdd refers to the following table:

indexing	Period of time	Offset of	Explanation of the invention
				0-4	5	0-4	Configuring 3, 4 and 5 reservations for LTE TDD
5-14	10	0-9
				15-34	20	0-19
35-74	40	0-39
				75-154	80	0-79
155-314	160	0-159
				315-634	320	0-319
635-1023	2	0-1in FDD0-9forTDD	The indices 637-Index of method for selecting two SRS symbols from within a field

TABLE 1SRS Signaling index

With reference to the same design principles, the following table may also be used to describe:

indexing	Period of time	Offset of	Explanation of the invention
				0-319	320	0-319
320-479	160	0-159
				480-559	80	0-79
560-599	40	0-39
				600-619	20	0-19
620-629	10	0-9	6 -->
				630-634	5	0-4	Configuring 3, 4 and 5 reservations for LTE TDD
635-1023	2	0-1in FDD0-9 for TDD	Index 637-

TDD safeguardThe offset value for TDD is the index for 10 methods to select two SRS symbols from within a field

TABLE 2SRS Signaling index

If the period values are considered to be arranged from small to large according to the order of natural numbers, the following table can be generated to describe the SRS signaling indexes of the unified lte tdd and lte fdd specified users:

indexing	Period of time	Offset of	Explanation of the invention
				0-9	2	0-1：LTEFDD0-9：LTEFDD	2-9 the offset value for LTE FDD reserved TDD is an index to 10 methods of selecting two SRS symbols from within a field
10-14	5	0-4	Configuring 3, 4 and 5 reservations for LTE TDD
				15-24	10	0-9
25-44	20	0-19
				45-84	40	0-39
85-164	80	0-79
				165-324	160	0-159
325-1023	320	0-1inFDD0-9forTDD	Index 645 + 1023 reservations

TABLE 3SRS Signaling index

To further ensure the consistent design of LTEFDD and LTETDD, flexibility of some LTETDD signaling may be sacrificed, and the number of indexes that can be selected by the LTETDD system in 2ms period is limited to 2, so that the number of indexes of LTEFDD and LTETDD will be identical, which can be embodied by using the following table 4:

indexing	Period of time	Offset of	Explanation of the invention
				0-1	2	0-1
2-6	5	0-4	Configuring 3, 4 and 5 reservations for LTE TDD
				7-16	10	0-9
17-36	20	0-19	7 -->
				37-76	40	0-39
77-156	80	0-79
				157-316	160	0-159
317-1023	320	0-1in FDD	Index 637-1023 Retention

TABLE 4SRS Signaling index

In the above described method, the configuration methods of the two systems are unified as much as possible for the purpose of making the LTEFDD and LTETDD as consistent as possible. Here, these particular methods are optimized for LTETDD; if the LTEFDD and LTETDD can be allowed to use different tables, tables 1-4 can be used only for the LTETDD system, and the LTEFDD is designed to use different specific methods, which mainly reflects that only two indexes need to be occupied in the 2ms period in the LTEFDD system.

Described above is a configuration method for an SRS based on redefining the 2ms period and the 5ms period of LTETDD. Here, redefining the 2ms period of configurations 0-2 and 6, the actual period is 5 ms; redefining the 2ms period of the configuration 3-5, the actual period is 10 ms. Therefore, in some calculations that need to use SRS period values, 2ms periods configured with 0-2 and 6 need to be calculated according to 5ms periods; and calculating the 2ms period configured with 3-5 according to the 10ms period.

If the concept of redefining the 2ms period and the 5ms period of the LTETDD is not adopted, the 2ms period and the 5ms period are not supported in some cases, and it is directly defined that two SRS symbols are configured within 5ms or 10 ms. Here, in some calculations that require the use of the SRS period value, the period value is directly used for the calculation. Tables 5 and 6 are two possible specific configuration methods. Here, the period values listed in table 5 or table 6 are the actual period values. And assume a method that needs to support all C (5, 2) ═ 10 two SRS symbols selected within a field.

In table 5, when the index value is 0 to 9, 2SRS symbols are configured in a 5ms period, and the corresponding offsets 0 to 9 are actually indexes to 10 methods of selecting two SRS symbols from a field. When the indices are 10-14, 1SRS is configured in a 5ms period, and the offset represents the location of the allocated SRS symbol. When the index is 15-24, 2SRS are configured in a 10ms period, and the corresponding offsets 0-9 are actually indexes of 10 methods for selecting two SRS symbols from a field. When the indices are 25-34, 1SRS is configured in a 10ms period, and the offset represents the location of the allocated SRS symbol.

Indexing	Period of time	Offset of	Explanation of the invention
				0-9	5	0-9	The offset value is an index to 10 methods of selecting two SRS symbols from within a field

10-14	5	0-4
				15～24	10	0～9	The offset value is an index to 10 methods of selecting two SRS symbols from within a field
25-34	10	0-9
				35-54	20	0-19
55-94	40	0-39
				95-174	80	0-79
175-334	160	0-159
				335-654	320	0-319	8 -->
655-1023			Retention

TABLE 5SRS Signaling index

Table 6 is equivalent to table 5, except that the order of a downlink is adjusted, thereby constituting another embodiment, and the present invention does not limit the appearance order of the SRS period values in the table.

In table 6, when the index value is 0 to 9, 2SRS symbols are configured in the 5ms period, and the corresponding offsets 0 to 9 are actually indexes to 10 methods of selecting two SRS symbols from the field. When the index is 10-19, 2SRS are configured in a 10ms period, and the corresponding offsets 0-9 are actually indexes of 10 methods for selecting two SRS symbols from a field. When the indices are 20-24, 1SRS is configured in a 5ms period, and the offset represents the location of the allocated SRS symbol. When the indices are 25-34, 1SRS is configured in a 10ms period, and the offset represents the location of the allocated SRS symbol.

Indexing	Period of time	Offset of	Explanation of the invention
				0-9	5	0-9	The offset value is an index to 10 methods of selecting two SRS symbols from within a field
10-19	10	0-9	The offset value is an index to 10 methods of selecting two SRS symbols from within a field
				20～24	5	0～4
25-34	10	0-9
				35-54	20	0-19
55-94	40	0-39
				95-174	80	0-79
175-334	160	0-159
				335-654	320	0-319
655-1023			Retention

TABLE 6SRS Signaling index

Instead of using the concept of redefining the 2ms period and 5ms period of the LTETDD, the LTETDD system is defined not to support 2ms periods and to support the configuration of two SRS symbols within each half frame (5 ms). In some calculations which need to utilize the SRS period value, the configurations 0-2 and 6 need to be calculated according to the 5ms period; and calculating the configuration 3-5 according to a 10ms period. Table 7 is one possible specific configuration method. Here, a method is assumed that all C (5, 2) ═ 10 two SRS symbols selected in a field need to be supported.

In table 7, when the index value is 0 to 9, 2SRS symbols are configured in the 5ms period, and the corresponding offsets 0 to 9 are actually indexes to 10 methods of selecting two SRS symbols from the field. When the indices are 10-14, 1SRS is configured in a 5ms period, and the offset represents the location of the allocated SRS symbol. When the indices are 15-24, 1SRS is configured in a 10ms period, and the offset represents the location of the allocated SRS symbol.

Indexing	Period of time	Offset of	Explanation of the invention
				0-9	5	0-9	The offset value is an index to 10 methods of selecting two SRS symbols from within a field
10-14	5	0-4	9 -->
				15-24	10	0-9
25-44	20	0-19
				45-84	40	0-39
85-164	80	0-79
				165-324	160	0-159
325-644	320	0-319
				645-1023			Retention

TABLE 7SRS Signaling index

For the above configuration of transmitting two SRS symbols per period, C (5, 2) ═ 10 indexes are adopted to achieve a fully flexible configuration. Here, one mapping method from the index to the selected two SRS symbols is as follows. Defining that when the UpPTS contains 2SRS symbols, the first SRS symbol is represented by SRS subframe offset 0; the second SRS symbol is indicated by SRS subframe offset 1. It is defined that when UpPTS contains 1SRS symbol, this SRS symbol is represented by SRS subframe offset 1. The SRS symbols defining the other subframes are represented by an offset (i.e., 2, 3, or 4) of the subframe in which they are located. Thus, one possible mapping method from C (5, 2) ═ 10 indices to the two selected SRS symbols is as in table 8.

Indexing	Offset of
		0	0，1
1	0，2
		2	1，2
3	0，3
		4	1，3
5	0，4

6	1，4
		7	2，3
8	2，4
		9	3，4

Table 8 mapping method from 10 indexes to two selected SRS symbols

And the system network side adopts RRC signaling to transmit the SRS signaling generated in the step one.

The system side further maps the generated SRS message to a transmission channel and a physical channel, and sends the SRS message to the user equipment through an antenna after corresponding other processing is carried out.

Referring to fig. three, the schematic diagram of the apparatus for transmitting the SRS signaling specified by the user of the present invention mainly includes an SRS information generating module (301) for the specified user, SRS information is mapped to a transmission channel module (302), and the SRS signaling specified by the specified user is transmitted through an antenna module (304) after passing through a physical channel mapping module (303).

Referring to fig. 4, a schematic diagram of an lte ue transmission SRS apparatus (406) of the present invention is mainly configured to generate an SRS sequence by a module (401), receive other SRS transmission information (including information such as a cyclic offset value, a comb value, and a specific bandwidth used for SRS transmission) according to SRS transmission information of a designated user received by a module (402) and SRS transmission information received by a module (403), adjust power at an appropriate timing on allocated physical resources by a module (405), and send SRS signaling of the designated user at an antenna module (407).

This section presents two embodiments of the invention. In the following description, a detailed description of publicly known functions or devices, etc. is omitted in order to avoid making the description of the present patent redundant.

The first embodiment:

this embodiment is applicable to LTETDD configuration 1 (602).

An LTE network side generates a signaling message required by SRS transmission of a designated user, selects an index 635 according to a table 1, and for an LTETDD system, the index indicates a 2ms period and indicates that the designated user transmits the SRS (601 or 604) at the first symbol position and the second symbol position of the UpPTS; for the lte fdd system, the user is designated to transmit SRS at the OFDM symbol position available for SRS transmission in the first subframe of the 2ms period. The system then sends this index information to the designated user via transport channel mapping and transport channel mapping.

Second embodiment:

this embodiment is applicable to LTETDD configuration 3 (704).

An LTE network side generates a signaling message required by SRS transmission of a designated user, selects an index 637 according to table 1, and indicates a 2ms period to an LTETDD system to indicate that the designated user transmits the SRS at a first symbol position (701) of an UpPTS and an available OFDM symbol position of a first normal uplink subframe (subframe 2) (702); for the lte fdd system, the index is reserved, so the system does not use the index to send SRS signaling for a specific user. The system then sends this index information to the designated user via transport channel mapping and transport channel mapping.

Although the present invention has been described in conjunction with the preferred embodiments thereof, it will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention. Accordingly, the present invention should not be limited by the above-described embodiments, but should be defined by the appended claims and their equivalents.

Claims (1)

1. A method for transmitting uplink monitoring reference signal (SRS) information by an LTETDD user terminal (UE) comprises the following steps:

a) the UE receives information N for SRS transmission;

b) the UE generates an SRS sequence;

c) if the information N is in the range of 0-9, the UE determines that the SRS period is two milliseconds, determines a subframe offset used for indicating an SRS transmission position in a half frame based on the information N, and transmits the SRS at a position corresponding to the subframe offset;

for an SRS period of 2 milliseconds, the correspondence between the information N in the range of 0-9 and the subframe offset used for indicating the SRS transmission position in the half frame is as follows:

information N Subframe offset 0 0，1 1 0，2 2 1，2 3 0，3 4 1，3 5 0，4 6 1，4 7 2，3 8 2，4 9 3，4

And when the UpPTS includes 2SRS symbols, the transmission position of the first SRS symbol is indicated by SRS subframe offset 0, and the transmission position of the second SRS symbol is indicated by SRS subframe offset 1; when the UpPTS includes 1SRS symbol, the transmission position of this SRS symbol is indicated by SRS subframe offset 1.