WO2013139011A1

WO2013139011A1 - Method and device for mapping search space of downlink control channel

Info

Publication number: WO2013139011A1
Application number: PCT/CN2012/072727
Authority: WO
Inventors: 王轶; 张元涛; 周华
Original assignee: 富士通株式会社
Priority date: 2012-03-21
Filing date: 2012-03-21
Publication date: 2013-09-26
Also published as: CN103988563A; CN103988563B

Abstract

Embodiments of the present invention provide a method and device for mapping a search space of a downlink control channel (PDCCH). The method comprises: determining, according to a resource allocation manner, a search space allocated to a PDCCH; and spaced by a resource block (RB), mapping each candidate position (candidate) of the PDCCH to a time-frequency resource corresponding to the search space. According to the method and device in the embodiments of the present invention, different candidates of the PDCCH are mapped to different RBs, so as to obtain a frequency selectivity scheduling gain, thereby improving the performance of the PDCCH.

Description

Method and device for mapping search space of downlink control channel

The present invention relates to a wireless communication technology, and more particularly to a mapping method and apparatus for a search space of a downlink control channel in an LTE (Long Term Evolution) / LTE-A (LTE-Advanced) system. Background technique

With the evolution of the EUTRA (Evolved Universal Terrestrial Radio Access) network, many new scenarios have emerged, such as heterogeneous networks with the same or different cell IDs. New features of the data channel and control channel should be introduced. For the Enhanced PDCCH (Physical Downlink Control Channel), consider the following:

Ability to support increased control channel capacity;

Can support frequency domain ICIC (Inter-Cell Interference Coordination); can improve space reuse of control channel resources;

Ability to support beamforming and/or diversity;

Ability to operate on new carrier types and MBSFN (Multicast Broadcast Single Frequency Network) sub-frames;

It can coexist on the same carrier as the legacy UE (User Equipment).

Desired features include the ability to schedule frequency selection and the ability to mitigate inter-cell interference. Based on the above requirements, the E-PDCCH (Enhanced-PDCCH, Enhanced PDCCH) can be located in a traditional PDSCH (Physical Downlink Shared Channel) area. A major problem with E-PDCCHs in the traditional PDSCH region is the design of the search space. The UE blindly detects its E-PDCCH in the area allocated by the network side. This area can be semi-statically configured through high-level signaling or dynamically configured through Layer 1 signaling. For E-PDCCH, there are mainly two mapping schemes, namely, local mapping and distributed mapping. For local mapping, it is desirable to obtain a frequency selective scheduling gain and a frequency selective beamforming gain, that is, an eNB (base station) can transmit an E-PDCCH on a subcarrier having a better channel response.

In existing systems, the search space includes a plurality of candidate locations with different Aggregation Levels, as shown in Table 1, for each of the aggregation levels, multiple candidate locations are configured. Such as How to map multiple candidate locations onto the search space to obtain frequency selective scheduling gain or frequency diversity gain is very important for E-PDCCH.

In Rel-8 of the LTE system, the function of the search space is defined as follows:

L{(Y _k + m') mod[N _{CCE Ic} /∑} + i

Where Y _k is a UE-specific parameter related to the C-RNTI (Cell Radio Network Temporary Identifier), i=0, "·Λ-1, N _{cc3⁄4 (t} is the control area of the subframe k) The total number of CCEs (Control Channel Elements).

With this function, the starting point of the search space of each UE can be determined using the UE-specific parameters. However, considering that the parameter Y _{k is} only related to the number of subframes and the C-RNTI, there is no guarantee that the search space includes subcarriers having good channel quality. Therefore, the frequency scheduling gain cannot be obtained.

In order for the UE to obtain the frequency scheduling gain, the E-PDCCH resource should be configured or dynamically configured through UE-specific high layer signaling. If the E-PDCCH resources are configured by higher layer signaling, it is important to design the search space to support at least one candidate location on the carrier with better channel quality. If the existing search space function is reused, multiple candidate locations are mapped onto adjacent subcarriers, for example, 4 candidate locations are mapped onto the same resource block, which may limit all candidate locations of the E-PDCCH to experience The same channel fading, therefore, the frequency scheduling gain cannot be obtained.

It should be noted that the above description of the technical background is only for the purpose of facilitating the clear and complete description of the technical solutions of the present invention, and is convenient for understanding by those skilled in the art. The above technical solutions are not considered to be well known to those skilled in the art simply because these solutions are set forth in the background section of the present invention. Summary of the invention

An object of the embodiments of the present invention is to provide a mapping method and apparatus for searching a downlink control channel to obtain a frequency selective scheduling gain.

According to an aspect of the embodiments of the present invention, a mapping plane of a search space of a downlink control channel is provided. The method includes:

Determining a search space allocated for a downlink control channel (PDCCH) according to a resource allocation manner;

Each candidate location of the PDCCH is mapped to a time-frequency resource corresponding to the search space by using a resource block (RB) as an interval.

According to an aspect of the present invention, a base station is provided for performing mapping of a search space of a downlink control channel, where the base station includes:

a determining unit that determines a search space allocated for a downlink control channel (PDCCH) according to a resource allocation manner; and a mapping unit that maps each candidate location (candidate) of the PDCCH to the search space by using a resource block RB as an interval On the time-frequency resources.

According to an aspect of an embodiment of the present invention, a computer readable program is provided, wherein, when the program is executed in a base station, the program causes a computer to perform a mapping method of a search space of a downlink control channel described above in the base station .

According to an aspect of an embodiment of the present invention, a storage medium storing a computer readable program, wherein the computer readable program causes a computer to perform a mapping method of a search space of a downlink control channel described above in a base station.

The beneficial effects of the embodiments of the present invention are as follows: The frequency selective scheduling gain is obtained by mapping different candidates of the PDCCH into different RBs, thereby improving the performance of the PDCCH.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and the accompanying drawings, which illustrate the manner in which the principles of the invention can be employed. It should be understood that the embodiments of the invention are not limited in scope. The embodiments of the present invention include many variations, modifications, and equivalents within the spirit and scope of the appended claims.

Features described and/or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, in combination with, or in place of, features in other embodiments. .

It should be emphasized that the term "comprising" or "comprising" is used to mean the presence of a feature, component, step or component, but does not exclude the presence or addition of one or more other features, components, steps or components. DRAWINGS

Many aspects of the invention can be better understood with reference to the following drawings. The components in the figures are not drawn to scale, but only to illustrate the principles of the invention. In order to facilitate the illustration and description of some parts of the invention, the figures The corresponding part may be enlarged or reduced. Elements and features described in one of the figures or one embodiment of the invention may be combined with elements and features illustrated in one or more other figures or embodiments. In the accompanying drawings, like reference numerals refer to the In the drawing:

1 is a flowchart of a method for mapping a search space of a downlink control channel according to an embodiment of the present invention;

2 is a schematic diagram of an embodiment of mapping using equation (1) or equation (2);

Figure 3 is a schematic diagram of another embodiment of mapping using equation (1) or equation (2); Figure 4 is a schematic diagram of one embodiment of mapping using equation (3);

Figure 5 is a schematic diagram of one embodiment of mapping using equation (4);

Figure 6 is a schematic diagram of one embodiment of mapping using equation (5);

FIG. 7 is a schematic diagram of the composition of a base station according to an embodiment of the present invention. detailed description

The foregoing and other features of the embodiments of the invention will be apparent from the These embodiments are merely exemplary and are not limiting of the invention. In order to enable the person skilled in the art to easily understand the principles and embodiments of the present invention, the embodiments of the present invention are PDCCH (hereinafter referred to as PDCCH or new PDCCH or E-PDCCH) transmitted in the PDSCH region in the LTE-A system. The mapping of the search space is described as an example, but it can be understood that the embodiment of the present invention is not limited to the above system, and is applicable to other systems or scenarios involving mapping of the search space of the PDCCH.

Example 1

The embodiment of the invention provides a mapping method for a search space of a downlink control channel. Figure 1 is a flow chart of the method. Referring to Figure 1, the method includes:

Step 101: Determine a search space allocated for a downlink control channel (PDCCH) according to a resource allocation manner. Step 102: Map, by using resource blocks (RBs), candidate locations of the PDCCH to the search space. On the time-frequency resources.

In this embodiment, the PDCCH is used to carry downlink control information (DCI, Downlink Control Information), and the control channel element (CCE, Control Channel Element) is configured as a minimum unit. As shown in Table 1, one PDCCH may be L. The CCE is composed of L. The value ranges from 1, 2, 4, and 8. It indicates the different aggregation levels of the PDCCH. The L CCEs may be in the M ^w positions. Send on.

In this embodiment, the resource allocation manner is, for example, typeO, typel, type2, etc., and according to different resource allocation manners, the search space allocated for the PDCCH may be determined. For example, based on the resource allocation method of type O, six RBGs (Resource Block Groups) are allocated to the PDCCH. The length of the RBG is different according to different system bandwidths, for example, the system bandwidth is 10 MHz, and the RBG size is 3. The RBs are equivalent to allocating 18 RBs to the PDCCH. For example, based on the resource allocation method of typeO, three RBGs are allocated to the PDCCH. If the system bandwidth is 10 MHz and the RGB size is 3 RBs, it is equivalent to assigning 9 RBs to the PDCCH. For another example, based on the resource allocation method of type 2, 12 RBs are allocated to the PDCCH. The resource allocation mode is configured by the system and can be reported to the user through high-level signaling. Each RB may include multiple CCEs. In this embodiment, each RB includes four CCEs as an example.

The above-mentioned types of resource allocation modes are only examples, and the embodiments of the present invention are not limited thereto. As the technology develops, new resource allocation modes, such as the RB-level bitmap mode, may occur. The method of the embodiment of the present invention can also be used in this resource allocation mode.

In this embodiment, according to different aggregation levels, each candidate position of the E-PDCCH is mapped to the allocated E-PDCCH resource by using the step size of the newly defined unit (for example, in steps of RB) to obtain frequency selection. Schedule the gain. That is, different candidate locations of the PDCCH are allocated to different time-frequency resources as much as possible, and different parts of one candidate location are allocated to adjacent time-frequency resources.

In an embodiment, if the number M ^(RB) of RBs of the search space allocated for the PDCCH is not smaller than the number M ^w of candidate positions of the PDCCH, that is, Μ ^(ΚΒ) Μ ⁽ then each candidate location of the PDCCH ⁾ Mapping to different RBs of time-frequency resources corresponding to the search space.

For example, if the number of RBs ^(RB) of the search space allocated for the PDCCH is 8, then when L=l or 2, the number of candidate locations of the PDCCH ^Mw is 6, satisfying Μ ^(ΚΒ) Μ ^(Ι , ie, The number of RBs allocated for the PDCCH is sufficient to drop all candidate locations of the PDCCH, and each candidate location of the PDCCH is directly mapped into a different RB.

In one embodiment, if the number of RB's PDCCH search space is allocated to M ^(RB) is smaller than the number of candidate positions M ^w, i.e. M ^(RB) <M ^W, the first PDCCH in the M ^{( RB)} candidate locations are mapped to different RBs of the time-frequency resource corresponding to the search space, and the remaining candidate locations are mapped to different RBs of the time-frequency resource corresponding to the search space according to the cyclic shift.

For example, the number of RBs ^(RB) of the search space allocated for the PDCCH is 4, then when L=l or 2, The number of candidate positions M ^(L·) of the PDCCH is 6, and M ^(RB) < M ^{(L) is} satisfied, that is, the number of RBs allocated for the PDCCH is insufficient to drop all candidate positions of the PDCCH, and then 4 candidates are received first. The locations are mapped into the four RBs, and the remaining two candidate locations are mapped into the first RB and the second RB according to the cyclic shift.

In the embodiment of the present invention, in the foregoing two embodiments, for different aggregation levels, the starting point of the candidate position of the PDCCH may be located in the same RB, or may be located in different RBs.

For example, if the starting point of the candidate position of the PDCCH is located in the first RB when L=1, the starting point of the candidate position of the PDCCH may be located in the first RB or in the second RB when L=2; The starting point of the candidate position of the PDCCH when L=4 may be located in the first RB, or may be located in the third RB or the fourth RB. And so on.

In the embodiment of the present invention, in the foregoing two embodiments, for different RBs, the candidate locations of the PDCCH may be mapped to different CCE sequence numbers in different RBs, or may be mapped to the same CCE sequence number location in different RBs. That is, each candidate location of the PDCCH mapped to a different RB is the same or different in position of the CCEs on the different RBs.

For example, if the first candidate location of the PDCCH is mapped to the fourth CCE of the first RB, the second candidate location of the PDCCH may be mapped to the fourth CCE of the second RB, or may be mapped to On the other CCEs of the second RB, for example, on the first CCE; for the same reason, the third candidate location of the PDCCH may be mapped to the fourth CCE of the third RB, or may be mapped to the third RB. On other CCEs, for example, on the second CCE; for the same reason, the fourth candidate location of the PDCCH may be mapped to the fourth CCE of the fourth RB, or may be mapped to other CCEs of the fourth RB, for example On the third CCE. And so on.

Wherein, if M ^(RB) <M ^(L) , the case of the above "same" may be that the M ^(RB) candidate positions of the PDCCH have the same CCE position on each RB, and the remaining candidate positions are in the respective RBs. The location of the CCE is the same. The case of the above "different" may be that the M ^(RB) candidate positions of the PDCCH have different CCE positions on the respective RBs, and the remaining candidate positions have different CCE positions on the respective RBs.

Wherein, if M ^(RB) M ^(L) , the case of the above "same" may be that the positions of the CCEs on the respective RBs of the candidate positions of the PDCCH are the same. For the above-mentioned "different" case, the candidate positions of the number of CCEs included in one RB may be a group, and the candidate locations in the group have different CCE positions on the respective RBs, and may not be grouped. Candidate location, its location on the CCE on each RB is not Same. Taking the foregoing as an example, M ^(RB) is 8, M ^w is 6, and one RB includes 4 CCEs, and the positions of the first 4 candidate positions on 4 RBs are different, and the last 2 candidate positions cannot be divided into one group. Then the positions of the two candidate locations are different on the other two RBs.

In this embodiment, if the aggregation level is not greater than the number of Control Channel Elements (CCEs) within each RB, all CCEs of one candidate location of the PDCCH are mapped into the same RB. For example, if the aggregation level is L=1 or 2 and one RB contains 4 CCEs, the above relationship is satisfied, and one or two CCEs included in one candidate position of the PDCCH are mapped into the same RB. For example, if the aggregation level is L=4 and one RB includes 4 CCEs, the above relationship is satisfied, and the four CCEs included in one candidate location of the PDCCH are mapped into the same RB.

In one embodiment, when the candidate locations of the PDCCH are located in different RBs for different aggregation levels, and for different RBs, the candidate locations of the PDCCH are mapped to the same CCE sequence location in different RBs:

The CCE of the mth candidate location of the PDCCH on the time-frequency resource corresponding to the search space may be determined according to the following formula:

Mod(N _{CC£ m} x mod(m, Μ ^(ΛΒ) ) + L(X _k + [m I Μ ^(ΛΒ) J) + ί, N _CCE ) ( 1 ) The PDCCH can also be determined according to the following formula The CCE of the mth candidate location on the time-frequency resource corresponding to the search space:

L {mod(((N _CC£)

/L])}+ i (2) where N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured by the upper layer, which is used to distinguish the starting position of different users in the E-PDCCH resource. One parameter. For L = 1, it represents the relative offset from the starting CCE of the E-PDCCH resource. For example, the E-PDCCH resource is 4 RBs, that is, 16 CCEs, and X _k = l means starting from the 2nd CCE of the 1st RB. X _k = 10 means starting from the 3rd CCE of the 3rd RB. For L=2, according to the method provided by the embodiment of the present invention, the corresponding starting point is different; i=0, 〜, L-1, L is an aggregation level, and N _CCE is a CCE configured for the E-PDCCH. The total number.

In order to make the method of the embodiment more clear and understandable, the mapping method of the embodiment will be described below by way of specific examples with reference to the accompanying drawings.

2 is a schematic diagram of mapping of a search space of a PDCCH according to an embodiment of the present invention. In this embodiment, M ^(RB) = 4 and X _k = 2 are taken as an example. According to formula (1) or formula (2), the mapping result shown in Fig. 2 can be realized. Referring to FIG. 2, since one RB includes four CCEs, when M ^(RB) =4, N _CCE =16, that is, four RBs are allocated for the PDCCH, and a total of 16 CCEs are numbered from 0 to 15.

When L=l, the PDCCH is composed of 1 CCE. Referring to Table 1, the PDCCH has 6 candidate positions, that is, M ^w = 6, that is, the CCE of the PDCCH may be sent at 6 candidate locations. , then each candidate location corresponds to 1 CCE. Since X _k = 2, after shifting two CCEs, the six CCEs (logical time-frequency resources) starting from the third CCE (numbered 2) correspond to the six candidate locations of the PDCCH. With the method of this embodiment, the six candidate positions are mapped in the RB step to the four RBs corresponding to the physical time-frequency resource, and the number on the 10 MHz (50 RB) bandwidth shown in FIG. 2 is 0, 3. , 6, RB within RB. Since M ^(RB) <M ^(L) is satisfied, the CCEs (candidate positions) numbered 2, 3, 4, and 5 are first mapped into different RBs, and then, according to the cyclic displacement, the numbers are 6, 7 The CCE (candidate location) is mapped to the corresponding RB, where the RB refers to the RB corresponding to the physical resource. As shown in Figure 2, the CCE numbered 2 is mapped to the RB of the physical time-frequency resource numbered 0, and the CCE numbered 3 is mapped to the RB of the physical time-frequency resource number 3. The CCE is mapped to the RB of the physical time-frequency resource number 6. The CCE numbered 5 is mapped to the RB of the physical time-frequency resource number 48, and the number is 6 CCEs mapped to the physical time-frequency resource number. Within the RB of 0, the CCE numbered 7 is mapped into the RB of the physical time-frequency resource number 3. In this embodiment, each candidate location has the same location on the CCE in each RB. As shown in FIG. 2, the CCEs numbered 2, 3, 4, and 5 are mapped to the third CCE of each RB. The CCEs numbered 6,7 are mapped to the 4th CCE of each RB.

Similarly, when L=2, the PDCCH is composed of 2 CCEs. Referring to Table 1, the PDCCH has 6 candidate positions, that is, M ^w = 6, that is, the two CCEs of the PDCCH may be 6 When the candidate position is transmitted, each candidate location corresponds to 2 CCEs. Since X _k = 2, in this embodiment, after shifting 4 CCEs, 12 CCEs (logical time-frequency resources) starting from the fifth CCE (numbered 4) correspond to 6 candidate locations of the PDCCH. According to the method of the embodiment, the six candidate locations are mapped into the four RBs corresponding to the physical time-frequency resources by using the RB step size, and the physical time-frequency resources corresponding to the number shown in FIG. 2 are 0, 3, 6, Within 48 RB. Since the starting point of the candidate location is located in different RBs for different Ls in this embodiment, the first candidate location of the PDCCH (CCE numbered 4, 5) is mapped to the second RB when L=2 (corresponding to physical time) The frequency resource is numbered 3 in RB), and since M ^(RB) <M ^(L) is satisfied, the numbers are (4, 5), (6, 7), (8, 9), (10, 11) The CCE (candidate position) is mapped into different RBs, and the CCEs (candidate positions) numbered (12, 13) and (14, 15) are mapped into the corresponding RBs according to the cyclic displacement. In this embodiment, with the aforementioned L=l Similarly, the position of the CCEs in each RB is the same for each candidate location, as shown in FIG. 2, the candidate locations are numbered (4, 5), (6, 7), (8, 9), (10, 11). Both the first and second CCEs occupying each RB, and the candidate positions numbered (12, 13) and (14, 15) are the 3rd and 4th CCEs occupying each RB.

Similarly, when L=4, the PDCCH is composed of 4 CCEs. Referring to Table 1, the PDCCH has 2 candidate positions, that is, M ^w = 2, that is, the four CCEs of the PDCCH may be 2 When the candidate position is transmitted, each candidate location corresponds to 4 CCEs. Since X _k = 2, in this embodiment, after offsetting 8 CCEs, 8 CCEs starting from the ninth CCE (numbered 8) correspond to 2 candidate locations of the PDCCH. With the method of this embodiment, the two candidate locations are mapped into two RBs of the physical time-frequency resource in steps of RB. Similarly, since the starting point of the candidate location is located in different RBs for different Ls in this embodiment, the starting point (8, 9, 10, 11) of the candidate position of the PDCCH is mapped to the third RB when L=4 ( In the RB of the number 6 corresponding to the physical time-frequency resource, since each candidate location corresponds to 4 CCEs, one candidate location fills the entire RB.

In the above description, the RBs (numbers 0, 3, 6, 48) corresponding to the physical time-frequency resources to which the candidate locations of the PDCCH are mapped are also exemplified, and the embodiment is not limited thereto.

The mapping of candidate positions of the PDCCH shown in Fig. 2 can be realized by the above formula (1) or formula (2), that is, the CCE to which each candidate position of the PDCCH is mapped can be determined. In addition, as can be seen from Fig. 2, by the mapping of the formula (1) or the formula (2), at least one candidate position is allocated in each RB, and at most two candidate positions are allocated.

FIG. 3 is a schematic diagram of mapping of a search space of a PDCCH according to another embodiment of the present invention. In this embodiment, M ^(RB) = 8 and X _k = 3 are taken as an example. According to formula (1) or formula (2), the mapping result shown in Fig. 3 can be realized.

Referring to FIG. 3, since one RB includes four CCEs, when M ^(RB) =8, N _CCE =32, that is, eight RBs are allocated for the PDCCH, and a total of 32 CCEs are numbered from 0 to 31.

When L=l, the PDCCH is composed of one CCE. Referring to Table 1, the PDCCH has six candidate positions, that is, ^Mw =6. Since X _k =3, each candidate location corresponds to 1 CCE, after offsetting 3 CCEs, 6 CCEs starting from the fourth CCE (numbered 3) correspond to 6 candidate locations of the PDCCH. With the method of this embodiment, the six candidate locations are mapped into 8 RBs corresponding to the physical time-frequency resources in RB steps. Since M ^(RB) M ^W is satisfied, the numbers are directly 3, 4, and 5. The 6 CCEs (candidate locations) of 6, 7, and 8 are mapped to the 6 RBs corresponding to the physical time-frequency resources, and the starting point of the candidate location (that is, the CCE of the number 3) is located in the first corresponding to the physical time-frequency resource. Within RB (#1). Similarly, when L=2, the PDCCH is composed of two CCEs. Referring to Table 1, the PDCCH has six candidate positions, that is, M ^w = 6, and each candidate position corresponds to two CCEs. After shifting 6 CCEs, the 12 CCEs starting from the seventh CCE (numbered 6) correspond to the 6 candidate locations of the PDCCH. According to the method of the embodiment, the six candidate positions are mapped in the RB step to the eight RBs corresponding to the physical time-frequency resources. Since the starting points of the candidate positions are located in different RBs for different 1^, the loop is followed. The method of shifting, the first candidate location (CCE numbered 6,7) is mapped to the second RB (#2) corresponding to the physical time-frequency resource, and so on, numbered (8, 9), The CCEs (candidate positions) of (10,11), (12,13), (14,15), and (16,17) are respectively mapped to the numbers corresponding to the physical time-frequency resources: #3, #4, #5, #6, #7 in the RB (CCE positions are the same, are the 3rd, 4th CCE).

Similarly, when L=4, the PDCCH is composed of 4 CCEs. Referring to Table 1, the PDCCH has 2 candidate positions, that is, M ^w = 2, and each candidate position corresponds to 4 CCEs. After shifting 12 CCEs, 8 CCEs starting from the thirteenth CCE (numbered 12) correspond to 2 candidate locations of the PDCCH. The two candidate locations are mapped to the two RBs corresponding to the physical time-frequency resource by using the RB step, and the starting point of the candidate location is mapped to the fourth RB corresponding to the physical time-frequency resource. Within, since each candidate location corresponds to 4 CCEs, one candidate location fills the entire RB.

In the embodiment of FIG. 3, the RBs of numbers #1~#6 are not necessarily continuous on the corresponding physical time-frequency resources, for example, may also be discretely distributed as shown in FIG. 2. The consecutive numbers are given in Figure 3 to illustrate that the starting points of the candidate locations of the PDCCH are located in different RBs at different aggregation levels. In the following embodiments, the same situation exists, for example, the first RB (#1), the second RB (#2), the third RB (#3), and the fourth called the physical time-frequency resource. The RB (#4) and the like have the same meanings as the embodiment of Fig. 3 and will not be explained one by one.

In another embodiment, when the candidate locations of the PDCCH are located in the same RB for different aggregation levels, and for different RBs, the candidate locations of the PDCCH are mapped to the same CCE sequence location in different RBs:

Mod(N _{CC£ m} x mod(w', M ⁽ ) + L( _X _k I

+ \_m'l M ⁽ J) + i, N _CCE ) ( 3 ) where N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer, which is used to distinguish different users. A parameter of the starting point position in the E-PDCCH resource, the meaning of which is as described above, and is not described here again; i=0, 〜, L-1, L is the aggregation level, and N _CCE is the CCE configured for the E-PDCCH. The total number. In order to make the method of the embodiment more clear and understandable, the mapping method of the embodiment will be described below by way of specific examples with reference to the accompanying drawings.

FIG. 4 is a schematic diagram of mapping of a search space of a PDCCH according to an embodiment of the present invention. In this embodiment, M ^(RB) = 4 and X _k = 2 are taken as an example. According to formula (3), the mapping result shown in Fig. 4 can be realized.

Different from the mapping result shown in FIG. 2, in this embodiment, for different aggregation levels, the starting point of the candidate position of the PDCCH is located in the same RB.

Referring to FIG. 4, when L=l, the starting point of the candidate position of the PDCCH, that is, the CCE numbered 2 is mapped into the first RB of the physical time-frequency resource. When L=2, the starting point of the candidate position of the PDCCH, that is, the CCE numbered (4, 5) is also located in the first RB of the physical time-frequency resource. When L=4, the starting point of the candidate position of the PDCCH, that is, the CCE numbered (8, 9, 10, 11) is also located in the first RB of the physical time-frequency resource.

In another embodiment, when the candidate locations of the PDCCH are located in different RBs for different aggregation levels, and for different RBs, the candidate locations of the PDCCH are mapped to different CCE sequence numbers in different RBs:

Mod(N _{CC£ m} xm.d(w', M ^(RB) ) + mod ( + m' + \ m' IM ^(RB) J), N _{CCE RB} ) + i, N _CCE ) (4) where N _CCE – _RB is the number of CCEs in an RB; X _k is a UE-specific parameter of the high-level configuration, which is a parameter used to distinguish the starting position of different users in the E-PDCCH resource, and its meaning is as described above. This is not repeated here; i=0, ~, L-1, L is the aggregation level, and N _CCE is the total number of CCEs configured for the E-PDCCH.

FIG. 5 is a schematic diagram of mapping of a search space of a PDCCH according to an embodiment of the present invention. In this embodiment, M ^(RB) = 4 and X _k = 2 are taken as an example. According to formula (4), the mapping result shown in Fig. 5 can be realized.

Different from the mapping result shown in FIG. 2, in this embodiment, for different RBs, the candidate positions of the PDCCH are mapped to different CCE sequence numbers.

Different from the mapping result shown in FIG. 4, in this embodiment, for different aggregation levels, the starting point of the candidate position of the PDCCH is located in different RBs, and for different RBs, the candidate positions of the PDCCH are mapped to different CCE sequence numbers. .

Referring to FIG. 5, when L=l, the starting point of the candidate position of the PDCCH, that is, the CCE mapping numbered 2 Within the first RB of the physical time-frequency resource, the location of each candidate location of the PDCCH is different in each RB. For example, the CCE numbered 2 is located in the third CCE of the first RB of the physical time-frequency resource. The location, the CCE numbered 3 is located at the fourth CCE location of the second RB of the physical time-frequency resource, and the CCE numbered 4 is located at the location of the first CCE of the third RB of the physical time-frequency resource, number The CCE of 5 is located at the second CCE of the fourth RB of the physical time-frequency resource, and the CCEs numbered 6 and 7 are mapped according to the cyclic shift, and the CCE numbered 6 is located at the first of the physical time-frequency resources. The location of the fourth CCE of the RB, the CCE numbered 7 is located at the location of the first CCE of the second RB of the physical time-frequency resource.

Similarly, when L=2, the starting point of the candidate position of the PDCCH, that is, the CCE numbered (4, 5) is located in the second RB of the physical time-frequency resource, however, each candidate position of the PDCCH is in each RB. The location is different. For example, the CCE numbered (4, 5) is located at the first and second CCEs of the second RB of the physical time-frequency resource, and the CCE numbered (6, 7) is located at the third RB of the physical time-frequency resource. The location of the 3rd and 4th CCEs, the CCE numbered (8,9) is located at the 1st and 2nd CCEs of the fourth RB, and the CCE numbered (10, 11) is located at the physical time-frequency resource. The location of the 3rd and 4th CCEs of an RB, the CCE numbered (12,13) is located at the 3rd and 4th CCEs of the second RB of the physical time-frequency resource, numbered (14,15) The CCE is located at the position of the first and second CCEs of the third RB of the physical time-frequency resource. Wherein, each candidate location corresponds to two CCEs, and one RB includes four CCEs. Therefore, for the case of L=2, the phrase "each candidate location of the PDCCH is different in each RB" means continuous. The two candidate locations are different in position within their respective RBs.

Similarly, when L=4, the starting point of the candidate position of the PDCCH, that is, the CCE numbered (8, 9, 10, 11) is located in the third RB of the physical time-frequency resource, since each candidate position corresponds to 4 For a CCE, one RB contains four CCEs. Therefore, for the case of L=4, the CCE corresponding to one candidate location has already occupied the entire RB, and there is no "the location of each candidate location of the PDCCH is different in each RB".

In another embodiment, when the candidate locations of the PDCCH are located in the same RB for different aggregation levels, and the candidate locations of the PDCCH are mapped to different CCE sequence numbers in different RBs for different RBs:

Mod(N _{CC£ RB} x mod(w', M ^(RB) ) + mod ( + w') / ” + [_w7 M ^(RB) J), N _{CCE RB} ) + i, N _CCE ) ( 5 ) , N _{CCE RB} is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer, which is A parameter used to distinguish the starting point positions of different users in the E-PDCCH resource, the meaning of which is as described above, and is not described here; i=0, ~, L-1, L is the aggregation level, and N _CCE is The total number of CCEs configured by the E-PDCCH.

FIG. 6 is a schematic diagram of mapping of a search space of a PDCCH according to an embodiment of the present invention. This embodiment is based on

For example, M ^(RB) = 4 and X _k = 2, according to formula (5), the mapping result as shown in Fig. 6 can be realized.

Different from the mapping result shown in FIG. 2, in this embodiment, for different aggregation levels, the start point of the candidate position of the PDCCH is located in the same RB, and for different RBs, the candidate positions of the PDCCH are mapped to different CCE sequence numbers. .

Different from the mapping result shown in FIG. 4, in this embodiment, for different RBs, the candidate positions of the PDCCH are mapped to different CCE sequence numbers.

Different from the mapping result shown in FIG. 5, in this embodiment, for different aggregation levels, the starting point of the candidate position of the PDCCH is located in the same RB.

Referring to FIG. 6, when L=l, the starting point of the candidate position of the PDCCH, that is, the CCE numbered 2 is mapped to the first RB of the physical time-frequency resource, and the positions of the candidate positions of the PDCCH in each RB are located. Similar to FIG. 5, the description is omitted here.

Similarly, when L=2, the starting point of the candidate position of the PDCCH, that is, the CCE numbered (4, 5) is also located in the first RB of the physical time-frequency resource, and each candidate position of the PDCCH is in each RB. The position is similar to that of FIG. 5, and the description is omitted here.

Similarly, when L=4, the starting point of the candidate position of the PDCCH, that is, the CCE numbered (8, 9, 10, 11) is also located in the first RB of the physical time-frequency resource.

In the embodiments of Figures 2-6 above, the UE-specific parameters _Xk are variable for different subframes. It can also be seen from the above embodiments that if the aggregation level is not greater than the number of control channel elements (CCEs) within each RB, that is, L ≤ 4, all CCEs of one candidate location of the PDCCH are mapped to the same Within the RB.

According to the method of the present embodiment, after mapping each candidate location of the PDCCH to the time-frequency resource corresponding to the allocated search space, the RB configuration of the allocated search space and the sequence number of the CCE in the RB are notified to the UE, therefore, The method of an embodiment may further comprise the following steps:

Step 103: RB configuration and RB within the search space allocated for the downlink control channel (PDCCH) The sequence number of the CCE is sent to the UE.

Thereby, the number of blind detections of the UE can be reduced. In this embodiment, the transmission method is not limited. For example, the RB and/or CCE sequence number of the UE may be configured through higher layer signaling.

The method of the embodiment of the present invention maps different candidate locations of the PDCCH into different RBs, and obtains a frequency selective scheduling gain, thereby improving the transmission performance of the PDCCH.

The present invention also provides a base station, as described in the following embodiment 2. The principle of the problem solved by the base station is similar to the mapping method of the search space of the downlink control channel of the embodiment 1. Therefore, the specific implementation may refer to the embodiment. The implementation of the method of 1 will not be repeated here.

Example 2

The embodiment of the invention provides a base station for performing mapping of a search space of a downlink control channel. FIG. 7 is a schematic diagram of the composition of the base station. Referring to FIG. 7, the base station includes:

a determining unit 701, which determines a search space allocated for a downlink control channel (PDCCH) according to a resource allocation manner;

The mapping unit 702 maps each candidate candidate of the PDCCH to the time-frequency resource corresponding to the search space by using the resource block RB as an interval.

In one embodiment,

The mapping unit 702 maps each candidate location of the PDCCH to a time-frequency corresponding to the search space when the number M ^(RB) of RBs of the search space allocated for the PDCCH is not less than the number M ^w of the candidate locations. Within the different RBs of the resource.

In one embodiment,

Mapping unit 702 when the number of RB allocated to the PDCCH search space M ^(RB) is smaller than the number of candidate positions M ^w, the first PDCCH is M ^(RB) is mapped to the position candidate search spaces In the different RBs of the corresponding time-frequency resources, the remaining candidate locations are mapped into different RBs of the time-frequency resources corresponding to the search space according to the cyclic shift.

In the foregoing embodiment, for different aggregation levels, the mapping unit maps the start point of the candidate location of the PDCCH into a different RB or maps into the same RB.

In the foregoing embodiment, for different RBs, the mapping unit maps each candidate location of the PDCCH to a location of a different CCE of each RB, or to a location of the same CCE of each RB. In an embodiment, the mapping unit maps a start point of a candidate location of the PDCCH to a different RB for different aggregation levels, and for different RBs, the mapping unit uses each candidate of the PDCCH When the location is mapped to the location of the same CCE of each RB, the mapping unit 702 may determine the CCE of the mth candidate location of the PDCCH on the time-frequency resource corresponding to the search space according to the following formula:

Mod(N _CC£ ^ X mod(w', M ⁽ ) + L(X _k + [m IM ⁽ J) + i, N _CCE );

N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer; i=0, ~, L1, L are aggregation levels, and N _CCE is the total number of CCEs configured for E-PDCCH .

In an embodiment, the mapping unit maps a start point of a candidate location of the PDCCH to a different RB for different aggregation levels, and for different RBs, the mapping unit uses each candidate of the PDCCH When the location is mapped to the location of the same CCE of each RB, the mapping unit 702 may also determine the CCE of the mth candidate location of the PDCCH on the time-frequency resource corresponding to the search space according to the following formula:

L{mod(((N _CC£)

/∑])}+ i;

In an embodiment, the mapping unit maps a start point of a candidate location of the PDCCH to a different RB for different aggregation levels, and for different RBs, the mapping unit uses each candidate of the PDCCH When the location is mapped to the location of the different CCEs of the RBs, the mapping unit 702 may determine, according to the following formula, the CCEs of the mth candidate locations of the PDCCH on the time-frequency resources corresponding to the search space:

Mod(N _{CC£ m} x mod(w', M ^(RB) ) + mod(L(X _k + m' + [m IM ^(RB) J), N _CCE N _CCE ); where N _CCE — _RB is The number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer; i=0, ~, L1, L are aggregation levels, and N _CCE is the total number of CCEs configured for the E-PDCCH.

In an embodiment, the mapping unit maps a start point of a candidate location of the PDCCH to the same RB for different aggregation levels, and for different RBs, the mapping unit uses each candidate of the PDCCH When the location is mapped to the location of the same CCE of each RB, the mapping unit 702 may determine the CCE of the mth candidate location of the PDCCH on the time-frequency resource corresponding to the search space according to the following formula: Mod(N _{CC£ m} x mod(w', M ^(RB) ) + L([_X _k I + \_m' l M ^(RB) J) + i, N _CCE ); where N _CCE — _RB is a The number of CCEs in the RB; X _k is the UE-specific parameter configured in the upper layer; i=0, ~, L1, L is the aggregation level, and N _CCE is the total number of CCEs configured for the E-PDCCH.

In an embodiment, the mapping unit maps a start point of a candidate location of the PDCCH to the same RB for different aggregation levels, and for different RBs, the mapping unit uses each candidate of the PDCCH When the location is mapped to the location of the different CCEs of the RBs, the mapping unit 702 may determine, according to the following formula, the CCEs of the mth candidate locations of the PDCCH on the time-frequency resources corresponding to the search space:

Mod(N _{CC£ RB} x od(m',M ^(RB) ) + ηιοά(ζ([( _Α + m')/

N _{CCE RB} ) + i, N _CCE ); where N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer; i=0, ~, Ll, L is an aggregation level, N _CCE Is the total number of CCEs configured for the E-PDCCH.

In the foregoing embodiment, if the aggregation level is not greater than the number of Control Channel Elements (CCEs) within each RB, all CCEs of one candidate location of the PDCCH are mapped into the same RB.

In the foregoing embodiment, the UE-specific parameters _Xk are variable for different subframes.

In an embodiment, the base station may further include:

The sending unit 703 sends the RB configuration of the search space allocated for the downlink control channel (PDCCH) and the sequence number of the CCE in the RB to the UE.

The base station of the present embodiment maps different candidate locations of the PDCCH to the corresponding RBs, and obtains a frequency selective scheduling gain, thereby improving the transmission performance of the PDCCH.

The embodiment of the present invention further provides a computer readable program, wherein when the program is executed in a base station, the program causes the computer to perform the mapping method of the search space of the downlink control channel described in Embodiment 1 in the base station .

The embodiment of the present invention further provides a storage medium storing a computer readable program, wherein the computer readable program causes a computer to perform a mapping method of a search space of a downlink control channel according to Embodiment 1 in a base station.

The above apparatus and method of the present invention may be implemented by hardware, or may be implemented by hardware in combination with software. The present invention relates to a computer readable program that, when executed by a logic component, enables the logic component to implement the apparatus or components described above, or to cause the logic component to implement the various methods described above Or steps. Logic components such as field programmable logic components, microprocessors, processors used in computers, and the like. The invention also relates to A storage medium for storing the above programs, such as a hard disk, a magnetic disk, a compact disk, a DVD, a flash memory, or the like. The present invention has been described in connection with the specific embodiments thereof, and it should be understood by those skilled in the art that these descriptions are not intended to limit the scope of the invention. A person skilled in the art can make various modifications and changes to the present invention within the scope of the present invention.

Claims

Claim

A method for mapping a search space of a downlink control channel, where the method includes: determining a search space allocated for a downlink control channel (PDCCH) according to a resource allocation manner; and using the resource block (RB) as an interval, Each candidate location of the PDCCH is mapped to a time-frequency resource corresponding to the search space.

2. The method according to claim 1, wherein

If the number of RBs ^(RB) of the search space allocated for the PDCCH is not smaller than the number of candidate locations Μ ^(Ι, mapping each candidate location of the PDCCH to a different time-frequency resource corresponding to the search space) Within the RB.

3. The method according to claim 1, wherein

If the number M ^(RB) of RBs of the search space allocated for the PDCCH is smaller than the number M ^{(L) of} the candidate locations, first map M ^(RB) candidate locations of the PDCCH to the search space. Within the different RBs of the time-frequency resource, the remaining candidate locations are mapped into different RBs of the time-frequency resource corresponding to the search space according to the cyclic shift.

4. The method according to claim 1, wherein

If the aggregation level is not greater than the number of Control Channel Elements (CCEs) within each RB, then all CCEs of one candidate location of the PDCCH are mapped into the same RB.

5. The method according to any one of claims 1 to 4, wherein

For different aggregation levels, the starting point of the candidate location of the PDCCH is located in a different RB.

The method according to claim 5, wherein mapping to each candidate location of the PDCCH in a different RB, the locations of CCEs on the different RBs are the same or different.

The method according to claim 6, wherein, when mapping to a candidate location of the PDCCH in a different RB, when the locations of CCEs on the different RBs are the same, determining the PDCCH according to the following formula The CCE of the mth candidate location on the time-frequency resource corresponding to the search space:

Mod(N _{CC£ m} x mod(w', M ⁽ ) + L(X _k + [m' / M ⁽ J) + i, N _CCE );

N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer; i=0, . . . , L1, L is an aggregation level, and N _CCE is a CCE configured for the E-PDCCH. The total number.

8. The method according to claim 6, wherein when mapping to the PDCCH within different RBs For each candidate location, when the locations of the CCEs on the different RBs are the same, the CCEs of the mth candidate locations of the PDCCH in the time-frequency resources corresponding to the search space are determined according to the following formula:

L {mod(((N _CC£)

/L])}+ i ;

N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer; i=0,..., Ll, L is an aggregation level, and N _CCE is a CCE configured for the E-PDCCH. The total number.

9. The method according to claim 6, wherein, when mapping to each candidate location of the PDCCH in a different RB, when the locations of CCEs on the different RBs are different, determining the according to the following formula

CCE of the mth candidate location of the PDCCH on the time-frequency resource corresponding to the search space:

Mod(N _{CC£ m} xm.d(w', M ^(RB) ) + mod ( (3⁄4 + m' + \ m'l MJ), N _CCE N _CCE ) ; where N _CCE — _RB is an RB The number of CCEs; X _k is the UE-specific parameter of the high-level configuration; i=0,..., Ll, L is the aggregation level, and N _CCE is the total number of CCEs configured for the E-PDCCH.

10. The method according to any one of claims 1 to 4, wherein

For different aggregation levels, the starting point of the candidate location of the PDCCH is located in the same RB.

The method according to claim 10, wherein each of the candidate locations of the PDCCH that are mapped to different RBs has the same or different locations of CCEs on the different RBs.

The method according to claim 11, wherein, when mapping to each candidate location of the PDCCH in a different RB, when the locations of the CCEs on the different RBs are the same, determining the according to the following formula

Mod(N _CC£

+ [m IM ^(RB) J) + i, N _CCE );

The method according to claim 11, wherein, when mapping to each candidate location of the PDCCH in a different RB, when the locations of CCEs on the different RBs are different, determining the according to the following formula

Mod(N _{CC£ RB} x od(m',M ^(RB) ) + ηιοά(ζ([( ₄ + w')/ ” + [_ 7 J), N _{CC£ RB} ) + i, N _CCE ) ; N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer; i=0,..., Ll, L is an aggregation level, and N _CCE is a CCE configured for the E-PDCCH. The total number.

14. The method according to claim 7 or 8 or 9 or 12 or 13, wherein

The UE-specific parameters X _k are variable for different subframes.

The method according to claim 1, wherein the method further comprises:

The RB configuration of the search space allocated for the downlink control channel (PDCCH) and the sequence number of the CCE in the RB are sent to the UE.

A base station, configured to perform mapping of a search space of a downlink control channel, where the base station includes:

17. The base station according to claim 16, wherein

The mapping unit maps each candidate location of the PDCCH to a time corresponding to the search space when the number M ^(RB) of RBs of the search space allocated for the PDCCH is not less than the number M ^w of the candidate locations Frequency resources within different RBs.

18. The base station according to claim 16, wherein

When the RB number assigned to the mapping unit in a PDCCH search space M ^(RB) is smaller than the number of candidate locations M ^w, the first PDCCH is M ^(RB) is mapped to the position candidate search Within the different RBs of the time-frequency resource corresponding to the space, the remaining candidate positions are mapped into different RBs of the time-frequency resource corresponding to the search space according to the cyclic shift.

The base station according to any one of claims 16 to 18, wherein

For different aggregation levels, the mapping unit maps the start of the candidate location of the PDCCH into different RBs.

The base station according to claim 19, wherein the locations of the CCEs on the different RBs are the same or different, and are mapped to respective candidate locations of the PDCCHs in different RBs.

The base station according to claim 20, wherein, when mapping to a candidate location of the PDCCH in a different RB, when the locations of CCEs on the different RBs are the same, the mapping unit determines according to the following formula The CCE of the mth candidate location of the PDCCH on the time-frequency resource corresponding to the search space:

Mod(N _{CC£ m} x mod(w', M ⁽ ) + L(X _k + [m' / M ⁽ J) + i, N _CCE );

22. The base station according to claim 20, wherein: when mapping to the PDCCH within different RBs Each of the candidate locations, when the locations of the CCEs on the different RBs are the same, the mapping unit determines, according to the following formula, a CCE of the mth candidate location of the PDCCH on a time-frequency resource corresponding to the search space:

L {mod(((N _CC£)

/L])}+ i ;

The base station according to claim 20, wherein, when mapping to different candidate positions of the PDCCH in different RBs, when the positions of CCEs on the different RBs are different, the mapping unit determines according to the following formula CCE of the mth candidate position of the PDCCH on the time-frequency resource corresponding to the search space: mod(N _{CC£ m} xm.d(w', M ^(RB) ) + mod ( (3⁄4 + m' + \ m'l MJ), N _CCE N _CCE ); where N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer; i=0,... , Ll, L is an aggregation Horizontal, N _CCE is the total number of CCEs configured for the E-PDCCH.

The base station according to any one of claims 16 to 18, wherein

For different aggregation levels, the mapping unit maps the start of the candidate location of the PDCCH into the same RB.

The base station according to claim 24, wherein each of the candidate locations of the PDCCH mapped to different RBs has the same or different CCE positions on the different RBs.

The base station according to claim 25, wherein, when mapping to a candidate location of the PDCCH in a different RB, when the locations of CCEs on the different RBs are the same, the mapping unit determines according to the following formula CCE of the mth candidate position of the PDCCH on the time-frequency resource corresponding to the search space: mod(N _{CC£ m} x mod(w', M ⁽ ) + L( _X _k I

+ [m IM ^(RB) J) + i, N _CCE );

The base station according to claim 25, wherein, when mapping to different candidate positions of the PDCCH in different RBs, when the positions of CCEs on the different RBs are different, the mapping unit determines according to the following formula CCE of the mth candidate position of the PDCCH on the time-frequency resource corresponding to the search space: mod(N _{CC£ RB} xm.d( ',M ^(M) ) + od(L( (X _k + '/" + [_»ί7Μ ^(ί5) J), N _{CC£ RB} ) + i, N _CCE ); where N _CCE — _RB is the number of CCEs in an RB; X _k is a UE-specific parameter configured in a higher layer; i = 0, ..., Ll, L is the aggregation level, and N _CCE is the total number of CCEs configured for the E-PDCCH.

The base station according to claim 16, wherein the base station further comprises: And a sending unit that sends the RB configuration of the search space allocated for the downlink control channel (PDCCH) and the sequence number of the CCE in the RB to the UE.

A computer readable program, wherein the program causes a computer to perform a mapping method of a search space of a downlink control channel according to any one of claims 1 to 15 in the base station when the program is executed in a base station .

30. A storage medium storing a computer readable program, wherein the computer readable program causes a computer to perform a mapping method of a search space of a downlink control channel according to any one of claims 1-15 in a base station.