WO2011160473A1

WO2011160473A1 - Method and apparatus for transmitting channel measurement pilot

Info

Publication number: WO2011160473A1
Application number: PCT/CN2011/071774
Authority: WO
Inventors: 姜静; 张文峰; 孙云锋; 张晨晨
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-06-21
Filing date: 2011-03-14
Publication date: 2011-12-29
Also published as: CN102291350A

Abstract

A method for transmitting channel measurement pilot is provided in the present invention. The method includes that: M cells constitute a group of channel measurement pilot orthogonal cells, the location of time-frequency resources for transmitting the channel measurement pilot by any cell in the group is orthogonal with the location of time-frequency resources for transmitting the channel measurement pilot by other cells in the group; for any cell in the group, the channel measurement pilot is transmitted by avoiding the time-frequency resources occupied by a downlink specific pilot of the present cell. The corresponding apparatus is also provided in the present invention. The present invention not only ensures the orthogonality of the channel measurement pilot pattern in one group of cells, meets the measurement requirement of coordinated multiple point transmission, but also avoids the downlink specific pilot of antenna port 5.

Description

Channel measurement pilot transmission method and device

Technical field

The present invention relates to the field of communications, and in particular, to a channel measurement pilot transmission method and apparatus ₍ background technology)

In order to improve the throughput of the cell, inter-cell interference coordination, a new generation of wireless communication systems, such as Long-Term Evolution Advance (LTE-Advance), and International Mobile Telecommunication Advance (International Mobile Telecommunication Advance, simple

Transmission and Reception is hereinafter referred to as CoMP).

The LTE/LTE-A system is based on Orthogonal Frequency Division Multiplexing (OFDM) technology. In OFDM systems, communication resources are in the form of time-frequency two-dimensional. For example, in an LTE system, communication resources are divided in units of frames in the time direction. Each radio frame has a length of 10 ms and includes 10 sub-frames of length 1 ms. . Depending on the length of the Cyclic Prefix (CP), each subframe can contain 12 or 14 OFDM symbols. In the frequency direction, resources are divided into sub-carriers. In communication, the smallest unit of resource allocation is Resource Block (RB), and one physical resource block corresponding to physical resources (Physical RB) , referred to as PRB). A PRB contains 12 subcarriers in the frequency domain.

Two pilots of LTE-Advanced are defined in the 56 conferences of LTE: channel measurement pilot (hereinafter referred to as CSI-RS) and Demodulation Reference Signal (DMRS), where the explicit channel measurement pilot is Cell-specific (cell-specific), distributed more sparsely on time-frequency resources than demodulation pilots.

However, an effective solution has not been proposed for the problem of how channel measurement pilots are transmitted in the LTE-A system. Summary of the invention

The technical problem to be solved by the present invention is to provide a channel measurement pilot transmission method and apparatus. To solve the above technical problem, the present invention provides a channel measurement pilot transmission method, including:

The M cells form a set of channel measurement pilot orthogonal cells, and the time-frequency resources of any one of the cells in the group that transmit the channel measurement pilots are orthogonal to the time-frequency resource positions of the other cells in the group that transmit the channel measurement pilots;

For any cell in the group, the channel measurement pilot is transmitted by avoiding the time-frequency resource occupied by the downlink dedicated pilot of the cell.

Preferably, before transmitting the channel measurement pilot of the local cell, determining an index of the channel measurement pilot map according to the cell identifier (Cell ID) of the cell, and then using the time-frequency resource corresponding to the index as the sending the cell The channel measures the time-frequency resources used by the pilot.

Preferably, before transmitting the channel measurement pilot of the local cell, the predetermined time-frequency resource is used as the initial time-frequency resource used by the transmission channel measurement pilot, and then determined according to the cell identifier (Cell ID) of the cell. The bit index, according to the time-frequency shift amount corresponding to the shift index, performs cyclic shift (Vshift) processing on the initial time-frequency resource, and uses the cyclically shifted time-frequency resource as a channel measurement guide for transmitting the cell. Time-frequency resources used by the frequency.

Preferably, before transmitting the channel measurement pilot of the local cell, determining an index of the channel measurement pilot mapping according to the cell identifier (Cell ID) of the cell, and then using the time-frequency resource corresponding to the index as the transmission channel measurement pilot. The initial time-frequency resource used, according to the location of the downlink dedicated pilot (UTS) of the cell, determines whether the initial time-frequency resource of the cell needs to be adjusted, and if adjustment is needed, the initial time-frequency of the cell is used. The resource is cyclically shifted (Vshift) in the frequency domain, and the cyclically shifted time-frequency resource is used as the time-frequency resource for transmitting the channel measurement pilot of the cell. If no adjustment is needed, the cell is The initial time-frequency resource is used as a time-frequency resource for transmitting the channel measurement pilot of the cell.

Preferably, the step of determining an index of the channel measurement pilot mapping according to the cell identifier (Cell ID) of the cell comprises: determining channel measurement of the any cell according to the value of the cell identifier (cell ID) modulo M The index of the pilot map.

Preferably, said M is a multiple of 3. Preferably, the step of determining a shift index according to a cell identifier (Cell ID) of the cell includes: determining a shift index of the any cell according to a value obtained by modulo M of the cell identifier; where the M is 3 multiple.

Preferably, the initial time-frequency resource is: 5th, 6th symbols in the time domain, and 3rd, 4th, 8th, and 9th subcarriers in the frequency domain; the shift index has three, corresponding to three time-frequency shifts respectively. a bit quantity, where the first time shift shift corresponding to the first shift index is: zero; the second time shift shift corresponding to the second shift index is: time domain shifted by 4 symbols, before frequency domain Shifting 3 subcarriers; the third time shift shift corresponding to the third shift index is: 4 symbols are shifted back in the time domain, and 1 subcarrier is forwarded in the frequency domain.

Preferably, the three cells are in a group, the base station sends the time-frequency resource of the channel measurement pilot to one cell in the group, and the time-frequency resource position of the channel measurement pilot transmitted by the base station to the other two cells in the group is positive. The time-frequency resource of the first cell is: the 5th, 6th symbols in the time domain, and the 3rd, 4th, 8th, and 9th subcarriers in the frequency domain; the time-frequency resources of the second cell are: 2nd and 3rd symbols in the time domain, 2nd, 3rd, 10th, and 11th subcarriers in the frequency domain; time-frequency resources of the third cell are: 2nd and 3rd symbols in the time domain, and 0th in the frequency domain 1, 7, 7, 8 subcarriers.

Preferably, the three cells are in a group, the base station sends the time-frequency resource of the channel measurement pilot to one cell in the group, and the time-frequency resource position of the channel measurement pilot transmitted by the base station to the other two cells in the group is positive. And the time-frequency resource of the first cell is: a third symbol in the time domain, and the first, second, third, fifth, sixth, seventh, and ten subcarriers in the frequency domain; The time-frequency resources are: the second symbol in the time domain, and the second, third, fourth, sixth, seventh, eighth, and eleventh subcarriers in the frequency domain; the time-frequency resources of the third cell are: The third symbol, the 0th, 3rd, 4th, 5th, 7th, 8th, 9th, and 11th subcarriers in the frequency domain.

Preferably, the six cells measure pilot orthogonal cells for a group of channels, the base station sends time-frequency resources of channel measurement pilots to one cell, and time-frequency of channel measurement pilots sent by the base station to other cells in the group. The resource location is orthogonal, where: the time-frequency resource of the first cell is: a third symbol in the time domain, and the first, second, third, fifth, sixth, seventh, tenth, and ten subcarriers in the frequency domain; The time-frequency resource of the second cell is: the second symbol in the time domain, and the second, third, fourth, sixth, eighth, eighth, and eleventh subcarriers in the frequency domain; the time-frequency resource of the third cell is: The third symbol in the time domain, the 0th, 3rd, 4th, 5th, 7th, 8th, 9th, and 11th subcarriers in the frequency domain; the time-frequency resource of the fourth cell is: the 5th and 6th symbols in the time domain , the second, third, eighth, and nine subcarriers in the frequency domain; the time-frequency resource of the fifth cell is: the first time in the time domain Symbol, the first, second, third, fifth, sixth, ninth, and tenth subcarriers in the frequency domain; the time-frequency resources of the sixth cell are: the fifth and sixth symbols in the time domain, and the second in the frequency domain , 3, 7, 8 subcarriers.

In order to solve the above technical problem, the present invention further provides a channel measurement pilot transmitting apparatus, including: a grouping unit and a transmitting unit, wherein:

The grouping unit is configured to: group the M cells into a set of channel measurement pilot orthogonal cells, and any cell in the group sends the time-frequency resource of the channel measurement pilot and the time-frequency of the channel measurement pilot of other cells in the group. Resource location is orthogonal;

The sending unit is configured to: send, for any cell in the group, a channel measurement pilot that avoids the time-frequency resource occupied by the downlink dedicated pilot of the local cell.

Preferably, the device further includes a resource allocation unit, where the resource allocation unit is configured to: determine an index of the channel measurement pilot map according to a cell identifier (Cell ID) of any cell in advance, and then use the time-frequency resource corresponding to the index as The time-frequency resource used by the cell to transmit the channel measurement pilot is notified to the transmitting unit.

Preferably, the device further includes a resource allocation unit, where the resource allocation unit is configured to: before the sending unit sends the channel measurement pilot to the any cell, first use the predetermined time-frequency resource as the channel measurement pilot. The initial time-frequency resource is used, and then the shift index is determined according to the cell identifier (Cell ID) of the cell, and the initial time-frequency resource is cyclically shifted according to the time-frequency shift amount corresponding to the shift index ( The Vshift process is to notify the transmitting unit of the cyclically shifted time-frequency resource as a time-frequency resource used for transmitting the channel measurement pilot of the cell.

Preferably, the device further includes a resource allocation unit, where the resource allocation unit is configured to: determine an index of a channel measurement pilot map according to a cell identifier (Cell ID) of the cell, and then send the time-frequency resource corresponding to the index as a sending The initial time-frequency resource used by the channel measurement pilot is determined according to the location of the downlink dedicated pilot (URS) of the cell, and the initial time-frequency resource of the cell needs to be adjusted. If adjustment is needed, the cell is used. The initial time-frequency resource is cyclically shifted (Vshift) in the frequency domain, and the cyclically shifted time-frequency resource is used as the time-frequency resource for transmitting the channel measurement pilot of the cell, and if no adjustment is needed, The initial time-frequency resource of the cell is notified to the sending unit as a time-frequency resource used for transmitting a channel measurement pilot of the cell. The invention not only ensures that the CSI-RS patterns in a group of cells are orthogonal, satisfies the measurement requirements of the CoMP, but also avoids the URS (downlink dedicated pilot) of the antenna port 5, and does not affect the performance of the mobile terminal of the Release 8. BRIEF abstract

The drawings are intended to provide a further understanding of the invention, and are intended to be illustrative of the invention. In the drawing:

Figure 1 is a dedicated downlink pilot pattern for a cell;

2 is a channel measurement pilot pattern according to a first embodiment of the present invention;

3 is a channel measurement pilot pattern according to a second embodiment of the present invention;

4 is a channel measurement pilot pattern according to a third embodiment of the present invention;

FIG. 5 is a channel measurement pilot pattern according to a fourth embodiment of the present invention; FIG.

Figure 6a is a schematic diagram of a channel measurement pilot orthogonal cell 1;

Figure 6b is a schematic diagram 2 of a channel measurement pilot orthogonal cell. Preferred embodiment of the invention

The inventive concept is as follows: M cells are grouped into a set of channel measurement pilot orthogonal cells, and any cell in the group transmits time-frequency resources of channel measurement pilots and other cells in the group transmit channel measurement pilots. The time-frequency resource is orthogonal to the location; for any cell in the group, the channel measurement pilot is transmitted by avoiding the time-frequency resource occupied by the downlink dedicated pilot of the current cell.

Preferably, one of the following methods can be used:

Method 1: Before transmitting the channel measurement pilot of the local cell, determining an index of the channel measurement pilot mapping according to the cell identifier (Cell ID) of the cell, that is, an index of a pattern of the channel measurement pilot mapping, which may be referred to as An index of the channel measurement pilot map, or a pattern index called a channel measurement pilot, and then using the time-frequency resource corresponding to the index as the channel measurement pilot station that sends the cell Time-frequency resources used.

The determining the resource index according to the cell identifier (Cell ID) of the any cell includes: determining a resource index of the any cell according to the value of the cell identifier (cell ID).

Method 2: Before transmitting the channel measurement pilot of the local cell, first use the predetermined time-frequency resource as the initial time-frequency resource used for transmitting the channel measurement pilot, and then determine according to the cell identifier (Cell ID) of the cell. The shift index is subjected to cyclic shift (Vshift) processing on the initial time-frequency resource according to the time-frequency shift amount corresponding to the shift index, and the cyclically shifted time-frequency resource is used as the channel measurement for transmitting the cell. The time-frequency resources used by the pilot.

The determining the shift index according to the cell identifier (Cell ID) of the any cell includes: determining a shift index of the any cell according to the value of the cell identifier modulo M.

Preferably, said M is a multiple of three. The initial time-frequency resources are: 5th and 6th symbols in the time domain, and 3rd, 4th, 8th, and 9th subcarriers in the frequency domain, the shift index has three, corresponding to three time-frequency shift amounts, wherein, The first time-frequency shift amount corresponding to a shift index is: zero; the second time-frequency shift amount corresponding to the second shift index is: 4 symbols are shifted back in the time domain, and 3 subcarriers are forwarded in the frequency domain; The third time-frequency shift amount corresponding to the three-shift index is: 4 symbols are shifted back in the time domain, and 1 sub-carrier is forwarded in the frequency domain.

Method 3: Before transmitting the channel measurement pilot of the local cell, determine an index of the channel measurement pilot map according to the cell identifier (Cell ID) of the cell, and then use the time-frequency resource corresponding to the index as the channel measurement guide. The initial time-frequency resource used by the frequency determines whether the initial time-frequency resource of the cell needs to be adjusted according to the location of the downlink dedicated pilot (UTS) of the cell, and if the adjustment needs to be performed, the initial time of the cell is used. The frequency resource is cyclically shifted (Vshift) in the frequency domain, and the cyclically shifted time-frequency resource is used as the time-frequency resource for transmitting the channel measurement pilot of the cell. If no adjustment is needed, the cell is used. The initial time-frequency resource is used as a time-frequency resource for transmitting the channel measurement pilot of the cell.

When the cyclic shift processing is performed, reference may also be made to method 2, the time-frequency shift amount and the corresponding index are determined in advance, and then the shift index is determined according to the cell identifier (Cell ID) of the any cell, and then corresponding to the shift index according to the shift index. The time-frequency shift amount is cyclically shifted (Vshift) to the initial time-frequency resource.

Corresponding to any of the above methods, the channel measurement pilot of any cell occupies 8 REs in the frequency domain, and each Each RE corresponds to any one of the antenna ports.

Allocating frequency domain resources according to the modulo index can ensure that the channel measurement pilot patterns between a group of cells are orthogonal (that is, occupy different positions on time-frequency resources), so as to ensure that the mobile terminal can measure any one of the groups of cells. The channel information of the cell to support the channel information required by CoMP (Multipoint Cooperative Transmission).

Performing a Vshift process on the initial transmission position ensures that the channel measurement pilot in the cell does not collide with the URS (downlink dedicated pilot) of the same cell, and does not affect the orthogonality of the pattern of the cell and other cells on the other hand. The cell IDs after cell ID modulo M shift are orthogonal.

The apparatus for implementing the above method includes: a grouping unit and a sending unit, wherein:

a grouping unit, configured to group the M cells into a set of channel measurement pilot orthogonal cells, where any cell in the group sends the time-frequency resource of the channel measurement pilot and the time-frequency of the channel measurement pilot of other cells in the group Resource location is orthogonal;

And a sending unit, configured to send a channel measurement pilot to the time-frequency resource occupied by the downlink dedicated pilot of the local cell to any cell in the group.

Corresponding to the foregoing method 1, the apparatus further includes a resource allocation unit, configured to determine an index of a channel measurement pilot map according to a cell identifier (Cell ID) of any cell in advance, and then use the time-frequency resource corresponding to the index as The time-frequency resource used by the cell to transmit the channel measurement pilot is notified to the transmitting unit.

Corresponding to the foregoing method 2, the device further includes a resource allocation unit, configured to send the predetermined time-frequency resource as the channel measurement pilot before sending, by the sending unit, the channel measurement pilot to the any cell. The initial time-frequency resource is used, and then the shift index is determined according to the cell identifier (Cell ID) of the cell, and the initial time-frequency resource is cyclically shifted according to the time-frequency shift amount corresponding to the shift index ( The Vshift process is to notify the transmitting unit of the cyclically shifted time-frequency resource as a time-frequency resource used for transmitting the channel measurement pilot of the cell.

Corresponding to the foregoing method, the device further includes a resource allocation unit, configured to determine an index of a channel measurement pilot map according to a cell identifier (Cell ID) of the cell, and then send the time-frequency resource corresponding to the index as a sending The initial time-frequency resource used by the channel measurement pilot, according to the cell The location of the downlink dedicated pilot (URS) determines whether the initial time-frequency resource of the cell needs to be adjusted. If adjustment is needed, the initial time-frequency resource of the cell is cyclically shifted in the frequency domain (Vshift). Processing, using the cyclically shifted time-frequency resource as a time-frequency resource for transmitting a channel measurement pilot of the cell, and if no adjustment is needed, using the initial time-frequency resource of the cell as a channel measurement for transmitting the cell The time-frequency resource used by the pilot is notified to the transmitting unit.

It should be noted that the features in the embodiments and the embodiments in the present application may be combined with each other without conflict. The invention will be described in detail below with reference to the drawings in conjunction with the embodiments.

Embodiment 1

1 is a transmission position of a downlink dedicated pilot of each cell, whose initial position is a pattern in which the Cell ID is modulo three equal to 0, and the number of subcarriers in the frequency domain shift is determined by Cell ID mod 3 after determining the initial position, for example, Cell. ID mod 3=1 shifts one subcarrier backward from the initial position.

After determining the transmission location of the downlink dedicated pilot of each cell in the group, before transmitting the channel measurement pilot to any cell in the group, first calculate the pattern index of each cell according to the following formula, and the resources corresponding to the three pattern indexes respectively Time-frequency orthogonal:

0

Pattern index = mod ( cellID,3) = 1

2

After the Cell ID is modulo 3, the cell channel measurement pilots with the same residual value are mapped according to the same frequency domain resource. As shown in Figure 2, assuming that the Cell ID of a cell is modulo 3 and then 0, the CSI-RS pattern is mapped according to the pattern 1 in Figure 2, and the 5th and 6th symbols on the real-time domain (1 in the figure) The 3rd, 4th, 8th, and 9th subcarriers in the frequency domain are the channel measurement pilot transmission locations of the cell; 4, the cell ID of one cell is modulo 3 and then 1, then the CSI-RS pattern is according to FIG. In the pattern 2 mapping, the 2nd and 3rd symbols in the real-time domain, the 2nd, 3rd, 10th, and 11th subcarriers in the frequency domain are the pilot measurement pilot positions of the channel of the cell; assuming that the cell ID of a cell is modulo 3 2, the pattern of the CSI-RS is mapped according to the pattern 3 in FIG. 2, the 2nd and 3rd symbols in the real-time domain, and the 0th, 1st, 7th, and 8th subcarriers in the frequency domain are channel measurement pilots of the cell. Launch location. The thus mapped CSI-RS pattern can ensure that the patterns of a group of cells are time-frequency orthogonal. As shown in FIG. 6a, the cells 1, 2, and 3 are a set of channel measurement pilot orthogonal cells. The above arrangement may also be arbitrarily transformed. For example, the Cell ID of the cell is modulo 3 and is 0, and the CSI-RS is mapped according to the pattern 2; the Cell lD of the cell is modulo 3 and the CSI-RS is mapped according to the pattern 3; The Cell ID is modulo 2 after modulo 3, and its CSI-RS is mapped according to pattern 1. There are many ways to change. This article is no longer a description. As long as the Cell ID is modulo 3, the cells with different residual values can use different mapping methods.

After the above arrangement, the CSI-RS pattern of each cell avoids the URS of the antenna port 5 of the local cell, and the channel measurement pilots of the three cells ensure that the time-frequency resources are orthogonal. In this embodiment, it is not necessary to perform Vshift processing on the CSI-RS pattern of each cell.

As shown in FIG. 2, each pattern corresponds to 8 REs, and each RE corresponds to one antenna port, and the resource elements (Resources Elements, RE) corresponding to each antenna port in each pattern can be flexibly adjusted, that is, each The antenna port corresponds to the RE. In this pattern, every two antenna ports are coded Multiplexing (CDM) when the Orthogonal Complementary Code (OCC) = 2, that is, the same on the two adjacent symbols. The subcarrier is a CDM pair.

Embodiment 2

Determining a time-frequency resource after determining the transmission location of the downlink dedicated pilot of each cell in the group

(Figure 1 in Figure 3), before transmitting the channel measurement pilot to any cell in the group, first use the predetermined time-frequency resource as the initial time-frequency resource used for transmitting the channel measurement pilot, and then according to The cell identifier (Cell lD) of the cell determines the shift index, that is, how to shift according to the following formula:

0 if mod ( celllD ,3) = 0

V _shlft = i subacarrier - 3, symbol +4 if mod ( celllD,3) = 1

Subacarrier - 1, symbol + 4 if mod ( celllD , 3) = 2 According to the time-frequency shift amount corresponding to the shift index, the initial time-frequency resource is cyclically shifted (Vshift), and will be cyclically shifted. The time-frequency resource is used as the transmission position of the channel measurement pilot of the any cell. When the Cell ID modulo 3 is equal to 0, the CSI-RS is mapped according to the initial pattern. The 5th, 6th symbols in the real-time domain, the 3rd, 4th, 8th, and 9th subcarriers in the frequency domain are the channel measurement pilot transmission positions of the cell; when the Cell ID modulo 3 is equal to 1, the CSI-RS will be the initial pattern. Four symbols are shifted backward, three subcarriers are forwarded for mapping, the second and third symbols on the real-time domain, and the second, third, tenth, and eleventh subcarriers in the frequency domain are the pilot measurement pilot positions of the channel of the cell; When lD modulo 3 is equal to 2, the CSI-RS shifts the initial pattern by 4 symbols, moves one subcarrier forward to map, the 2nd and 3rd symbols on the real-time domain, and the 0th, 1st, 7th, and 8th sub-bands in the frequency domain. The carrier is the channel measurement pilot transmission location for the cell. The same cell channel measurement pilots of Vshift are mapped according to the same frequency domain resources. The thus mapped CSI-RS pattern can ensure that the patterns of a group of cells are time-frequency orthogonal. As shown in FIG. 6a, the cells 1, 2, and 3 are a set of channel measurement pilot orthogonal cells.

The above arrangement can also be arbitrarily transformed, and will not be described in detail herein.

After the above arrangement, the CSI-RS pattern of each cell avoids the URS of the antenna port 5 of the local cell, and the channel measurement pilots of the three cells ensure that the time-frequency resources are orthogonal.

The RE corresponding to each antenna port in each pattern can be flexibly adjusted. In this pattern, CDM (Code Division Multiplexing) in the time domain is performed every two antenna ports by using OCC=2 (OCC orthogonal spreading code), that is, the same subcarriers on two adjacent symbols are one CDM pair.

In this embodiment, the initial position of the CSI-RS may be any one of the three mapping patterns in FIG. 3. After the initial pattern is determined, the corresponding shift can still be determined according to the Cell ID, but only the position of the shift. Also adjust accordingly.

Embodiment 3

If mod ( celllD ,3) = 0

Pattern index = mod ( celllD , 3) = if mod ( celllD , 3) = 1

If mod ( celllD ,3) = 2

After the Cell ID is modulo 3, the cell channel measurement pilots with the same residual value are mapped according to the same frequency domain resource. As shown in FIG. 4, assuming that the cell ID of a cell is 0 after modulo 3, the pattern of the CSI-RS is mapped according to the pattern 1 in FIG. 4, the third symbol on the real-time domain, and the first and second in the frequency domain. , 3, 5, 6, 7, 9, 10 subcarriers are the channel measurement pilot transmission positions of the cell; 4, if one cell's Cell lD is modulo 3 and then 1, then the CSI-RS pattern is mapped according to the pattern 2 in FIG. The second symbol on the real-time domain, the second, third, fourth, sixth, eighth, tenth, tenth, and eleventh subcarriers in the frequency domain are the pilot transmission locations of the channel of the cell; H is not taken by the cell ID of one cell. After 3 is 2, the pattern of its CSI-RS is mapped according to the pattern 3 in Figure 4, the third symbol on the real-time domain, and the 0, 3, 4, 5, 7, 8, 9, 11 subcarriers in the frequency domain. A pilot transmission location is measured for the channel of the cell. The thus mapped CSI-RS pattern not only ensures that the time-frequency of the patterns between a group of cells is orthogonal, as shown in FIG. 6a, the cells 1, 2, and 3 are a set of channel measurement pilot orthogonal cells. Moreover, the CSI-Rs pattern of each cell can also avoid the URS of the antenna port 5 of the local cell.

The above arrangement can also be arbitrarily changed.

The RE corresponding to each antenna port in each pattern can be flexibly adjusted. In this pattern, the CDM of the frequency domain is performed by means of OCC=2 for every two antenna ports, that is, the RE of two adjacent carriers is a CDM pair.

Embodiment 4

Pattern index = mod ( cell!D,6):

After the Cell ID is modulo 3, the cell channel measurement pilots with the same residual value are mapped according to the same frequency domain resource. As shown in FIG. 5, assuming that the cell ID of a cell is modulo 6 and then 0, the CSI-RS pattern is mapped according to the pattern 1 in FIG. 5, and the third symbol on the real-time domain, the first and second in the frequency domain. 3, 5, 6, 7, 9, 10 subcarriers are the channel measurement pilot transmission locations of the cell; 4, the cell lD of one cell is modulo 6 and then 1, then the CSI-RS pattern is according to Figure 5. The pattern 2 in the map, the second symbol on the real-time domain, the 2nd, 3rd, 4th, 6th, 7th, 8th, 10th, and 11th subcarriers in the frequency domain are the letters of the cell The channel measurement pilot transmission position; H does not have a cell's Cell ID modulo 6 is 2, then its CSI-RS pattern is mapped according to the pattern 3 in Figure 5, the third symbol on the real-time domain, the 0th in the frequency domain 3, 4, 5, 7, 8, 9, 11 subcarriers are the channel measurement pilot transmission locations of the cell; 4, the cell ID of one cell is modulo 6 and then 3, then the CSI-RS pattern is followed. The pattern 4 in Figure 5 is mapped, the 5th and 6th symbols in the real-time domain, and the 2nd, 3rd, 8th, and 9th subcarriers in the frequency domain are the channel measurement pilot transmission positions of the cell; suppose the Cell ID of a cell is modulo 6 is 4, then the CSI-RS pattern is mapped according to the pattern 5 in Figure 5, the first symbol on the real-time domain, and the first, second, third, fifth, sixth, seventh, ninth, and ten subcarriers in the frequency domain. The pilot transmission position is measured for the channel of the cell; 4, the Cell ID of one cell is modulo 6 and then 5, and the pattern of the CSI-RS is mapped according to the pattern 6 in FIG. 5, and the 5th and 6th in the instant domain are Symbol, the 2nd, 3rd, 7th, and 8th subcarriers in the frequency domain are pilot measurement pilot transmission locations of the cell. The thus mapped CSI-RS pattern can not only ensure that the time-frequency of the patterns between a group of cells is orthogonal, as shown in FIG. 6b, the cells 1 , 2, 3 , 14, 17, 18 are a set of channel measurement pilot orthogonal cells. Moreover, the CSI-Rs pattern of each cell can also avoid the URS of the antenna port 5 of the local cell.

The RE corresponding to each antenna port in each pattern can be flexibly adjusted.

In addition, the pattern on the 6th and 7th symbols and the pattern on the 13th and 14th symbols are adjacent to each other.

CDM-T (code division multiplexing + time division multiplexing, that is, code division multiplexing between a group of antenna ports, time division multiplexing between different groups of antenna ports), that is, adjacent two symbols The same subcarrier is a CDM pair. Pattern 1, pattern 2, pattern 4, pattern 6 adjacent RE釆 is multiplexed by CDM-F (code division multiplexing + frequency division multiplexing), that is, the RE of two adjacent carriers is a CDM pair.

In summary, the present invention maintains the URS transmission of the LTE system, has little impact on LTE users, and provides pilot information required for high-order MIMO and COMP, which is beneficial for LTE-Advanced users to improve single-link quality. In addition, the CSI-RS time-frequency orthogonal between a group of cells is guaranteed to facilitate channel measurement of CoMP.

The above three embodiments may implement orthogonality of inter-cell CSI-RS according to one subframe, or implement time-frequency orthogonality of CSI-RS patterns of 3K cells by using K subframes.

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 executed by a computing device The program code is implemented so that they can be stored in the storage device by the computing device, or they can be separately fabricated into individual integrated circuit modules, or a plurality of modules or steps can be made into a single integrated circuit module. . Thus, the invention is not limited to any specific combination of hardware and software.

The above description 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 spirit and scope of the present invention are intended to be included within the scope of the present invention.

Industrial Applicability According to the present invention, the CSI-RS patterns in a group of cells are orthogonalized, the CoMP measurement requirements are met, and the URS (downlink dedicated pilot) of the antenna port 5 can be avoided, and the movement of the Release 8 is not affected. Terminal performance.

Claims

Claim

1. A channel measurement pilot transmission method, comprising:

2. The method of claim 1 wherein

Before transmitting the channel measurement pilot of the local cell, determining an index of the channel measurement pilot map according to the cell identifier of the cell, and then using the time-frequency resource corresponding to the index as a channel measurement pilot for transmitting the cell. Time-frequency resources used.

3. The method of claim 1, wherein

Before transmitting the channel measurement pilot of the local cell, the predetermined time-frequency resource is used as the initial time-frequency resource used by the transmission channel measurement pilot, and then the shift index is determined according to the cell identifier of the cell. According to the time-frequency shift amount corresponding to the shift index, the initial time-frequency resource is cyclically shifted, and the cyclically shifted time-frequency resource is used as the time-frequency resource used for transmitting the channel measurement pilot of the cell. .

4. The method of claim 1, wherein

Before transmitting the channel measurement pilot of the local cell, determining an index of the channel measurement pilot map according to the cell identifier of the cell, and then using the time-frequency resource corresponding to the index as the initial time-frequency used by the transmission channel measurement pilot The resource, according to the location of the downlink dedicated pilot of the cell, determines whether the initial time-frequency resource of the cell needs to be adjusted, and if adjustment is needed, cyclically shifts the initial time-frequency resource of the cell in the frequency domain. The cyclically shifted time-frequency resource is used as the time-frequency resource for transmitting the channel measurement pilot of the cell. If no adjustment is needed, the initial time-frequency resource of the cell is used as the channel measurement guide for transmitting the cell. Time-frequency resources used by the frequency.

5. The method of claim 2 or 3, wherein

The determining, according to the cell identifier of the cell, the index of the channel measurement pilot mapping comprises: determining an index of the channel measurement pilot mapping of the any cell according to the value of the cell identifier modulo M.

6. The method of claim 5, wherein the M is a multiple of three.

7. The method of claim 3, wherein

The step of determining a shift index according to the cell identifier of the cell includes: determining a shift index of the any cell according to the value of the cell identifier modulo M; the M is a multiple of 3.

8. The method of claim 7, wherein

The initial time-frequency resource is: 5th, 6th symbols in the time domain, and 3rd, 4th, 8th, and 9th subcarriers in the frequency domain; the shift index has three, corresponding to three time-frequency shift amounts, The first time shift shift corresponding to the first shift index is: zero; the second time shift shift corresponding to the second shift index is: 4 symbols are shifted in the time domain, and 3 slots are forwarded in the frequency domain. The third time-frequency shift corresponding to the third shift index is: 4 symbols are shifted back in the time domain, and 1 subcarrier is forwarded in the frequency domain.

9. The method of claim 2 or 3 or 4, wherein

The three cells are in a group, and the base station sends the time-frequency resource of the channel measurement pilot to one cell in the group, and the time-frequency resource position of the channel measurement pilot transmitted by the base station to the other two cells in the group is orthogonal, where :

The time-frequency resources of the first cell are: 5th and 6th symbols in the time domain, and 3rd, 4th, and 8th in the frequency domain.

The time-frequency resources of the second cell are: the second and third symbols in the time domain, and the second, third, ten, and eleventh subcarriers in the frequency domain; the time-frequency resources of the third cell are: The 2nd and 3rd symbols in the time domain, the 0th, 1st, 7th, and 8th subcarriers in the frequency domain.

10. The method of claim 2 or 3 or 4, wherein

The time-frequency resource of the first cell is: a third symbol in the time domain, and the first, second, third, fifth, sixth, seventh, and ten subcarriers in the frequency domain; time-frequency resources of the second cell The second symbol in the time domain, the second, third, fourth, sixth, seventh, eighth, and eleventh subcarriers in the frequency domain; the time-frequency resource of the third cell is: the third symbol in the time domain , 0, 3, 4, 5, 7, 8, 9, 11 subcarriers in the frequency domain.

11. The method of claim 2 or 3 or 4, wherein

Six cells measure pilot orthogonal cells for a group of channels, and the base station transmits channels to one cell The time-frequency resource of the measurement pilot is orthogonal to the time-frequency resource location at which the base station sends the channel measurement pilot to other cells in the group, where:

The time-frequency resource of the first cell is: a third symbol in the time domain, and the first, second, third, fifth, sixth, seventh, and ten subcarriers in the frequency domain; time-frequency resources of the second cell The second symbol in the time domain, the second, third, fourth, sixth, seventh, eighth, and eleventh subcarriers in the frequency domain; the time-frequency resource of the third cell is: the third symbol in the time domain The 0th, 3rd, 4th, 5th, 7th, 8th, 9th, and 11th subcarriers in the frequency domain; the time-frequency resources of the fourth cell are: 5th and 6th symbols in the time domain, and 2nd in the frequency domain 3, 8, 9 subcarriers; the time-frequency resource of the fifth cell is: the first symbol in the time domain, and the first, second, third, fifth, sixth, seventh, nine, and ten subcarriers in the frequency domain; The time-frequency resources of the sixth cell are: 5th and 6th symbols in the time domain, and 2nd, 3rd, 7th, and 8th subcarriers in the frequency domain.

12. A channel measurement pilot transmitting apparatus, comprising: a grouping unit and a sending unit, wherein: the grouping unit is configured to: group the M cells into a set of channel measurement pilot orthogonal cells, and send any cell in the group The time-frequency resource of the channel measurement pilot is orthogonal to the time-frequency resource position of the channel measurement pilot transmitted by other cells in the group;

The device according to claim 12, wherein the device further includes a resource allocation unit, where the resource allocation unit is configured to: determine an index of a channel measurement pilot map according to a cell identifier of any cell in advance, and then The time-frequency resource corresponding to the index is notified to the transmitting unit as a time-frequency resource used by the cell to transmit a channel measurement pilot.

The device according to claim 12, wherein the device further includes a resource allocation unit, where the resource allocation unit is configured to: before the sending unit sends a channel measurement pilot to the any cell, Determining the time-frequency resource as the initial time-frequency resource used for transmitting the channel measurement pilot, and then determining the shift index according to the cell identifier of the cell, according to the time-frequency shift amount corresponding to the shift index, the initial time-frequency The resource performs cyclic shift processing, and notifies the transmitting unit of the cyclically shifted time-frequency resource as a time-frequency resource used for transmitting the channel measurement pilot of the cell.

The device of claim 12, wherein the device further comprises a resource allocation unit, wherein the resource allocation unit is configured to: determine a channel measurement pilot map according to a cell identifier of the cell in advance The index of the shot, then the time-frequency resource corresponding to the index is used as the initial time-frequency resource used by the transmission channel measurement pilot, and according to the location of the downlink dedicated pilot of the cell, it is determined whether the initial time-frequency of the cell is needed. The resource is adjusted. If the adjustment is needed, the initial time-frequency resource of the cell is cyclically shifted in the frequency domain, and the cyclically shifted time-frequency resource is used as the channel measurement pilot for transmitting the cell. The frequency resource, if no adjustment is needed, notifies the sending unit of the initial time-frequency resource of the cell as a time-frequency resource used for transmitting a channel measurement pilot of the cell.