JP6237820B2 - Downlink control channel resource mapping method and apparatus - Google Patents

Description

  The present invention relates to a radio communication technique, and more specifically, to a resource mapping method and apparatus for a downlink control channel in an LTE (Long Term Evolution) / LTE-A (LTE-Advanced) system.

In the LTE system, each type of downlink control information (DCI, Downlink Control Information) is transmitted by the base station in the form of a physical downlink control channel (PDCCH, Physical Downlink Control Channel), and the data is transmitted by the base station to the physical downlink shared channel (PDSCH). , Physical Downlink Shared Channel). PDCCH and PDSCH appear in each subframe in the form of time division, and as shown in FIG. 1, 1 to N OFDM (Orthogonal Frequency Division Multiplexing) symbols are possible transmission areas of PDCCH, of which N = 1, 2, 3 or 4, and is configured by an upper layer, and from the (N + 1) th OFDM symbol is a PDSCH transmission region. The PDCCH supports spatial diversity multi-antenna transmission based on a cell reference signal (CRS), and the maximum number of transmission antennas is four. The PDCCH region is divided into a common search space and a user-specific (UE-specific) search space. The common search space for all users (UE, User Equipment) is the same, and all users search for their PDCCH in the same space. The user dedicated search space is related to the user's RNTI (Radio Network Temporary Identifier), and the user searches his / her PDCCH only in his / her space. When the user searches for PDCCH, there are four possible aggregation levels (ie, aggregation levels), ie, L = l, 2, 4, 8, and each type of aggregation level has multiple possible positions. Suppose we have multiple candidates (candidates). The specific position of each candidate can be calculated based on a predetermined criterion. As shown in Table 1, the PDCCH aggregation level corresponds to the control channel element (CCE) on a one-to-one basis, the minimum aggregation level L = l corresponds to one CCE, and 36 CCEs. Corresponds to RE (resource element).

  Multi-antennas are widely used in wireless communication systems to improve data transmission rates and frequency spectrum efficiency. In the LTE-Advanced system, the downlink supports up to eight transmission antennas, thereby achieving a transmission rate of 1 Gbps. PDSCH can not only improve the transmission rate by precoding and beamforming, but also can expand the coverage of the signal. However, PDCCH still cannot support 8 antenna transmissions and can only support transmission diversity of up to 4 antennas, so it can get the same beamforming gain as PDSCH. Can not. To further improve the performance of cell edge users, multipoint coordinated transmission technology based on multiple RRH (Remote Radio Head) network architectures separated by geographical location is expected to be widely used in future wireless communication systems. is there. In multiple RRH network architectures, the user's PDSCH in each RRH coverage is simultaneously scheduled to obtain cell-splitting gain and improve cell capacity. At the same time, the cell capacity can be improved by the PDSCH spatial multiplexing scheme of a plurality of users. However, since PDCCH based on conventional CRS cannot obtain cell division gain, people become interested in research on PDCCH based on DM-RS (DeModulation Reference Symbol). As shown in FIG. 2, the region is expanded from the region of the N OFDM symbols before to the PDSCH region from the (N + 1) th symbol. Through the signaling, the user can obtain the specific position of the new PDCCH region, i.e. subcarrier resources occupied in the frequency domain and / or information of OFDM symbols occupied in the time domain, and the user can obtain blind information in this region. Detection can be performed and each PDCCH can be accurately demodulated.

  The inventor has discovered that in the process of implementing the present invention, this kind of new PDCCH resource mapping is the current research direction.

  The introduction of the background art described above is only for the purpose of clearly and completely explaining the technical solution of the present invention so that those skilled in the art can understand it. Since these schemes are described in the background section of the present invention, the above scheme should not be considered well known to those skilled in the art.

  An object of an embodiment of the present invention is to provide a downlink control channel resource mapping method and apparatus capable of realizing the uniformity of the number of PDCCH resources for each user and ensuring that the performance of the PDCCH is not affected by the reference signal. There is.

According to an aspect of the present invention, there is provided a resource mapping method for a downlink control channel, of which the method includes:
Determining the number of resource sub-blocks that a predetermined number of enhanced control channel elements (eCCE) need to support based on the size of the resource sub-blocks in one resource block (RB);
Based on the number of resource subblocks that the predetermined number of eCCEs need to correspond to, determine the number of RBs that the predetermined number of eCCEs need to map; and the predetermined number of eCCEs need to be mapped Mapping the eCCE of the downlink control channel (PDCCH) to the RB based on the number of RBs, of which the resource sub-block corresponding to the eCCE in the PDCCH or a predetermined number of eCCEs has different positions in each RB, Method.

According to another aspect of an embodiment of the present invention, a base station is provided, and the base station is used for resource mapping of a downlink control channel, of which the base station is
A first determination unit for determining the number of required resource sub-blocks to which a predetermined number of enhanced control channel elements (eCCE) correspond based on the size of the resource sub-blocks in one resource block (RB);
A second determination unit for determining the number of RBs to which the predetermined number of eCCEs need to be mapped based on the number of resource sub-blocks to which the predetermined number of eCCEs need to correspond; and the predetermined number of eCCEs; Includes a mapping unit for mapping eCCEs of downlink control channels (PDCCH) to RBs based on the number of RBs that need to be mapped, of which resource sub-blocks corresponding to eCCEs or a predetermined number of eCCEs in the PDCCHs Are different base stations in each RB.

  According to another aspect of an embodiment of the present invention, a computer readable program is provided, of which when executing the program at a base station, the program sends the resource of the downlink control channel described above to the computer at the base station. Run the mapping method.

  According to still another aspect of the embodiment of the present invention, a storage medium storing a computer-readable program is provided, and the computer-readable program is provided with a resource mapping method for the downlink control channel described above in a base station. Let it run.

  The beneficial effect of the embodiment of the present invention is that the PDCCH of each user realizes the uniform number of PDCCH resources by changing the mapping order in each resource block (Resource Block) alternately. Can be guaranteed not to be affected by the reference signal.

  Based on the following description and drawings, specific embodiments of the present invention will be disclosed in detail to clarify the manner in which the principles of the present invention can be employed. In addition, embodiment of this invention is not limited by it on the range. Within the spirit and scope of the appended claims, the embodiments of the invention include all variations, modifications, and alternatives.

  Features described and / or illustrated for one embodiment may be used in one or more other embodiments in the same or similar manner, combined with features in other embodiments, or other embodiments. The features in can be replaced.

  Note that terms such as “inclusive / include”, as used herein, refer to the presence of a feature, the entire device, step or assembly, but the presence of one or more other features, the entire device, step or assembly. Or it does not exclude addition.

Many aspects of the invention can be better understood with reference to the following drawings. The parts in the drawings are not drawn to scale, but merely to illustrate the principles of the invention. Corresponding parts in the drawings may be enlarged or reduced to show or explain parts of the invention. Elements and features described in one drawing or embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments. Also, in the drawings, like numerals indicate corresponding parts in the several drawings and are used to indicate corresponding parts used in several embodiments.
It is a figure which shows the transmission area | region of PDCCH and PDSCH in a LTE system. It is a figure which shows the transmission area | region of new PDCCH and PDSCH. It is a figure which shows the reference signal position of the transmission area | region of new PDCCH. It is a figure which shows the transmission position of the new PDCCH of multiple users. 4 is a flowchart of a resource mapping method for a downlink control channel in an embodiment of the present invention. It is a figure which shows the resource mapping in one Example of this invention. It is a figure which shows the resource mapping in the other Example of this invention. It is a figure which shows the resource mapping in the other Example of this invention. It is a figure which shows the resource mapping in the other Example of this invention. It is a figure which shows the structure of the base station in one Example of this invention.

  The foregoing and other features of the embodiments of the present invention will become more apparent from the accompanying drawings and the following specification. These embodiments are illustrative only and do not limit the invention. In order for those skilled in the art to easily understand the principles and embodiments of the present invention, in the embodiments of the present invention, PDCCH (hereinafter referred to as PDCCH or new PDCCH or ePDCCH) transmitted in the PDSCH region in the LTE-A system. However, it should be understood that the embodiments of the present invention are not limited to the above-described system, and can be applied to all other systems or scenarios related to PDCCH resource mapping. That's it.

  Currently, this type of new PDCCH resource mapping is divided into two major types, one is continuous resource mapping, that is, multiple CCEs of one PDCCH candidate are mapped to adjacent time frequency resources. is there. With this kind of mapping method, the base station transmits PDCCH to the user on the time frequency resource with good channel quality based on the channel information fed back by the user or the channel information measured by the base station itself, and the frequency selectivity Get scheduling gain. The other is discrete resource mapping, that is, a plurality of CCEs of one candidate of PDCCH are mapped to non-adjacent time frequency resources. This type of mapping scheme allows the base station to acquire frequency domain diversity gain and guarantee the performance of PDCCH even when channel information cannot be obtained.

  The inventor discovered that one rational scheme maps multiple CCEs of one candidate to different resource blocks (RBs) in the process of realizing the present invention. In order to improve frequency spectrum efficiency, it is necessary to map PDCCH of multiple users to different subcarriers of the same resource block, that is, PDCCH of multiple users is multiplexed by FDM (Frequency-division multiplexing) method, Each user's PDCCH occupies M subcarriers, which are called enhanced control channel elements (eCCEs), as shown in FIGS. 3 is a diagram showing possible resource positions on one RB of a new PDCCH, and FIG. 4 is a diagram showing possible resource positions on one RB of a new PDCCH of multiple users. .

  However, in the new PDCCH region, there are various types of reference signals, for example, cell common reference (for example, CRS) signals and demodulation reference signals (for example, DM-RS), as shown in FIG. Therefore, when mapping a new PDCCH, it is necessary to reserve the position of the reference signal in advance, thereby causing the PDCCH resource to change as the overhead of the reference signal changes. As shown in FIG. 4, in the PDCCH region of user 4, 12 REs are occupied by reference signals, and in the PDCCH region of user 2, 8 REs are occupied by reference signals, and the PDCCHs of these two users are The number of occupying resources will be different, which will change the performance accordingly and affect its robustness. This is one problem to be solved.

  In view of this, an embodiment of the present invention provides a resource mapping method and apparatus for a downlink control channel, in which a new PDCCH of each user changes the mapping order in each resource block (Resource Block, RB) alternately. In this way, it is possible to achieve a uniform number of new PDCCH resources for each user and to ensure that the performance of the new PDCCH is not affected by the reference signal.

  Hereinafter, a detailed description will be given based on specific examples.

  An embodiment of the present invention provides a resource mapping method for a downlink control channel. FIG. 5 is a flowchart of the method. Referring to FIG. 5, the method includes the following steps.

  Step 501: Based on the size of resource sub-blocks in one resource block (RB), the number of resource sub-blocks to which a predetermined number of enhancement control channel elements (eCCE) need to correspond is determined.

  Among them, each RB is divided into a plurality of smaller resource sub-blocks according to needs. For example, when four user PDCCHs are multiplexed using one RB, one RB includes four Can be divided (divided) into smaller resource sub-blocks. The present embodiment is not limited to a specific division strategy and division method.

  Among them, since one CCE corresponds to 36 REs, the number of resource sub-blocks corresponding to one eCCE can be determined based on the size of each resource sub-block. Among these, when the number of resource sub-blocks corresponding to one eCCE is not an integer, a plurality of eCCEs correspond to an integer number of resource sub-blocks, thereby determining the correspondence between the two. For example, when one eCCE corresponds to 1.5 resource sub-blocks, it is determined that two eCCEs correspond to three resource sub-blocks.

  Step 502: Based on the number of resource sub-blocks that the predetermined number of eCCEs need to correspond to, determine the number of RBs that the predetermined number of eCCEs need to map.

  Of these, in one preferred embodiment, the number of resource sub-blocks that a predetermined number of eCCEs need to correspond to is the same as the number of RBs that it needs to map, eg, one eCCE is 2 When corresponding to one resource sub-block, one eCCE needs to be mapped to two RBs, that is, two resource sub-blocks corresponding to one eCCE are located in two RBs, respectively. In another embodiment, the number of RBs to be mapped by the predetermined number of eCCEs may be determined according to the resource configuration status, for example, one eCCE corresponds to three resource sub-blocks. In this case, one eCCE may be mapped to two RBs according to the resource configuration status, that is, three resource sub-blocks corresponding to one eCCE are located in two RBs. .

  Step 503: Based on the number of RBs to which the predetermined number of eCCEs need to be mapped, the eCCE of the downlink control channel (PDCCH) is mapped to the RBs, of which the eCCE or the predetermined number of eCCEs in the PDCCH corresponds The sub-block has a different position in each RB.

  Among them, since the PDCCH aggregation level has a one-to-one correspondence with CCE / eCCE, the number of PDCCH eCCEs can be determined based on the aggregation level. For example, if aggregation level L = 1, it is determined that one PDCCH includes one eCCE, and if aggregation level L = 2, one PDCCH is determined to include two eCCEs. If aggregation level L = 4, it is determined that one PDCCH includes 4 eCCEs, and if aggregation level L = 8, it is determined that one PDCCH includes 8 eCCEs. Therefore, based on the number of RBs that a predetermined number of eCCEs need to map, one or a plurality of eCCEs of the PDCCH can be mapped to a corresponding number of RBs. For example, if one eCCE corresponds to two resource sub-blocks, it is necessary to map to two RBs. In this case, if aggregation level L = l, that is, one PDCCH If one eCCE of the PDCCH is included, the two resource sub-blocks corresponding to this one eCCE of the PDCCH are mapped to two RBs, and one RB corresponds to the resource sub-block of the eCCE, and the aggregation level If L = 2, that is, if one PDCCH includes two eCCEs, the four resource sub-blocks corresponding to the two eCCEs in the PDCCH are mapped to four RBs, and each RB Corresponds to the resource sub-block of the eCCE. Since it can be inferred based on this, detailed description is omitted here.

  Among these, according to the present embodiment, the resource sub-blocks to which the eCCEs in the PDCCH or the predetermined number of eCCEs correspond have different positions on each RB. Still, an example is that one eCCE corresponds to two resource sub-blocks and needs to be mapped to two RBs. According to the method of this embodiment, the first eCCE corresponding to the eCCE The positions of the resource sub-blocks in the first RB are different from the positions of the second resource sub-block corresponding to the eCCE in the second RB. As a result, the number of resources occupied by each PDCCH becomes equal or nearly equal.

  Among them, in one embodiment, the resource sub-block corresponding to the eCCE in the PDCCH or a predetermined number of eCCEs cyclically moves in the position in each RB. In another embodiment, the position in each RB of the resource sub-block corresponding to the eCCE in the PDCCH or a predetermined number of eCCEs is set in advance.

  In the above-described embodiment, the cyclic method of the cyclic circulation movement may be determined based on the size of the eCCE or the reference signal overhead in the RB or the size of the aggregation level, or the predetermined position may be determined. You may do it. Among them, the size of eCCE is the number of resource sub-blocks that one eCCE corresponds to, and the size of the aggregation level is the size of aggregation level, which is the number of eCCEs for one PDCCH. To determine how many RBs one PDCCH needs to be mapped to. Hereinafter, a description will be given based on a specific example.

  In the above-described embodiment, the cyclic method of the cyclic circulation movement may be determined based on a predetermined strategy, or the preset position may be determined, that is, the size of the eCCE or the aggregation level. Does not change with size change. For example, the cyclic method of the cyclic circulation movement or the preset position may be installed on a fixed one. It is only necessary to ensure that the resource sub-blocks corresponding to the eCCE based on the PDCCH have different positions in each RB, and that the number of resources occupied by each PDCCH is equal or substantially equal.

  According to one embodiment of the present example, the positions of resource sub-blocks corresponding to a predetermined number of eCCEs in PDCCH in each RB periodically circulate. For example, when one eCCE corresponds to two resource sub-blocks and needs to be mapped to two RBs, the position of the first resource sub-block corresponding to the eCCE in the first RB is If it is the 2i-l resource sub-block, the second resource sub-block corresponding to the eCCE is the 2i resource sub-block at the 2nd RB, of which i is from 0 Is also a large natural number. That is, the position of the first resource sub-block corresponding to the eCCE in the first RB and the position of the second resource sub-block corresponding to the eCCE in the second RB are compatible. is there. Among them, when the number of eCCEs of PDCCH is larger than the above-mentioned predetermined number, the above-described mapping method is repeated (overlapping) with the number of RBs corresponding to the above-mentioned predetermined number as one cycle. For example, if aggregation level L = 2, one PDCCH includes 2 eCCEs, corresponds to 4 resource sub-blocks, and is mapped to 4 RBs. In this case, 2 RBs are 1 And the above mapping scheme is repeated. At this time, among the four resource sub-blocks to which the PDCCH corresponds, the previous two resource sub-blocks have a compatible relationship on the previous two RBs. Yes, the latter two resource sub-blocks have a compatible relationship in the latter two RBs.

  According to another embodiment of the present example, the position of the resource sub-block corresponding to the eCCE in the PDCCH in each RB periodically circulates. For example, if one eCCE corresponds to two resource sub-blocks and aggregation level L = 2, four resource sub-blocks corresponding to two eCCEs in one PDCCH correspond to four RBs To map. In this case, the position of the first resource sub-block corresponding to the eCCE in the first RB is the 4i-3th resource sub-block, and the second resource sub-block corresponding to the eCCE is the second resource sub-block. The position in 2 RBs is the 4i-2 resource sub-block, the 3rd resource sub-block corresponding to the eCCE is the 4i-l resource sub-block in the 3rd RB , The fourth resource sub-block corresponding to the eCCE is the 4i-th resource sub-block at the fourth RB, where i is a natural number greater than 0. That is, the position of each resource sub-block corresponding to the eCCE in each RB is in a rotational displacement relationship.

  According to another embodiment of the present example, the position of each resource RB corresponding to a predetermined number of eCCEs in the PDCCH is set in advance in each RB. For example, when one eCCE corresponds to three resource sub-blocks and needs to be mapped to three RBs, each resource sub-block corresponding to the eCCE has a fixed position in the RB May be set in advance. Similarly, when the number of eCCEs of PDCCH is larger than the above-mentioned predetermined number, the number of RBs to which the above-mentioned predetermined number corresponds is set as one cycle, the above mapping scheme is repeated, and each resource sub-block has a position in the RB. It may be set in advance.

  In the above-described three embodiments, the number of resources occupied by each PDCCH is equal or substantially equal in both cases of periodic cyclic movement and preset. That is, since the number of REs occupied by each user's PDCCH is approximately equal, the performance of the PDCCH can be guaranteed not to be affected by the reference signal.

  In order to make the resource mapping method of the downlink control channel of this embodiment easier to understand, a detailed description will be given below based on some specific examples.

  FIG. 6 is a diagram showing PDCCH resource mapping in one embodiment of the present invention.

  Referring to FIG. 6, in this embodiment, four users are multiplexed using one RB. One RB is divided into four smaller resource sub-blocks, which are numbered unitl to 4, respectively, and each unit (element) includes three subcarriers. According to the method of this embodiment, one eCCE needs to correspond to two units based on the size of the unit, and it is determined that each is mapped to two RBs. In this embodiment, for the reference signal, it is assumed that the rank value that DM-RS can support is mnk = 4, and that CRS can support two antennas.

  According to the method of this embodiment, when Aggregation Level L = l, since the PDCCH of each user includes one eCCE, the mapping relationship between the eCCEs of four users and the time frequency resources is If j is mapped to the 2i-l units of the first RB, the user j is mapped to the 2i units of the second RB. That is, with 2 RBs as a cycle, the 2i-l unit and the 2i unit are exchanged with each other. Of these, i is a natural number greater than 0.

  According to the method of the present embodiment, when Aggregation Level L> 1, for example, when L = 2, 4 or 8, the number of RBs corresponding to one PDCCH is larger than 2, and at this time, the above-mentioned replacement The scheme may be repeated, that is, two RBs are set as one period, and mapping is performed alternately in the two RBs.

  In the embodiment of FIG. 6, description is given by taking as an example that the PDCCH of user 1 and user 2 is compatible with unitl and unit2 of different RBs, and the PDCCH of user 3 and user 4 is compatible with units3 and unit4 of different RBs However, the present embodiment is not limited to this, and it is only necessary to ensure that the number of resources occupied by each user's PDCCH is almost equal for any mapping. For example, the user 1 PDCCH occupies the first RB unitl and the second RB unit4, the user 2 PDCCH occupies the first RB unit2 and the second RB unit3, User 3's PDCCH may occupy unit 3 of the first RB and unit 2 of the second RB, and user 4's PDCCH may occupy unit 4 of the first RB and unitl of the second RB .

  According to the PDCCH resource mapping scheme shown in FIG. 6, the PDCCH of user 1 occupies the first RB unitl and the second RB unit2 and the number of resources distributed (allocated) is 24 + 28 = 52, user 2's PDCCH occupies the first RB's unit2 and second RB's unitl, the number of resources distributed to it is 28 + 24 = 52, and user 3's PDCCH is the first RB unit3 and second RB unit4 are occupied, and the number of resources distributed to them is 28 + 24 = 52, and user4's PDCCH is the first RB unit4 and the second RB Occupies unit3 and the number of resources distributed to it is 24 + 28 = 52. As can be seen, each user's PDCCH is assigned the same number of resources, which may ensure that the performance of the PDCCH is not affected by the reference signal.

  FIG. 7 is a diagram showing PDCCH resource mapping in another embodiment of the present invention.

  Referring to FIG. 7, in the present embodiment, six users perform multiplexing using one RB. One RB is divided into six smaller resource sub-blocks, which are numbered as units 1 to 6, respectively, and each unit includes two sub-carriers. According to the method of this embodiment, one eCCE needs to correspond to three units based on the unit size, and it is determined that each unit is mapped to three RBs. In the present embodiment, for the reference signal, it is assumed that the rank value that DM-RS can support is rank = 4, and that CRS can support two antennas.

  According to the method of this embodiment, if Aggregation Level L = l, each user's PDCCH includes one eCCE, so the mapping relationship between the 6 users' eCCE and the time-frequency resource is that the user 1's PDCCH is The unit1 of the first RB, the unit2 of the second RB, and the unit3 of the third RB are occupied, and the PDCCH of the user 2 is the unit2, the second RB, and the third RB of the first RB. Occupying unitl of user 3, PDCCH of user 3 occupies unit3 of 1st RB and 2nd RB, unit2 of 3rd RB, and PDCCH of user 4 is unit4 of 1 RB, The second RB unit5 and the third RB unit6 are occupied, and the user 5 PDCCH occupies the first RB unit5, the second RB unit6, and the third RB unit4. The PDCCH of user 6 occupies unit 6 of the first RB, unit 4 of the second RB, and unit 5 of the third RB. As can be seen, the number of resources occupied by each user's PDCCH is 52.

  According to the method of this embodiment, when Aggregation Level L> 1, for example, L = 2 or 4 or 8, the number of RBs corresponding to one PDCCH is larger than 3, and at this time, the above-described replacement scheme is repeated. In other words, three RBs are set as one cycle, and mapping is performed alternately in the three RBs.

  As in the embodiment of FIG. 6, this embodiment is not limited to a specific circulation method or mapping pattern, and it is only necessary to ensure that the number of resources occupied by each user's PDCCH is the same or substantially the same. . For example, if 3 units corresponding to 1 eCCE are mapped to 2 RBs each, the number of resources occupied by each user's PDCCH cannot be completely matched, but this kind of dynamic resource By adopting the mapping method, it is possible to greatly improve the performance of PDCCH compared to fixing each user's PDCCH at the RB fixed position.

  With the PDCCH resource mapping scheme shown in FIG. 7, since the number of resources distributed to each user's PDCCH is equal, it can be ensured that the performance of the PDCCH is not affected by the reference signal.

  FIG. 8 is a diagram showing PDCCH resource mapping in another embodiment of the present invention.

  Referring to FIG. 8, in this embodiment, three users multiplex using one RB as an example. One RB is divided into three smaller resource sub-blocks, numbered as units 1 to 3, respectively, and each unit includes 4 sub-carriers. According to the method of the present embodiment, one eCCE needs to correspond to 1.5 units based on the unit size, and the two eCCEs correspond to 3 units, and 3 e each. It is determined that it is mapped to RBs. In the present embodiment, for the reference signal, it is assumed that the rank value that DM-RS can support is rank = 4, and that CRS can support two antennas.

  According to the method of this embodiment, if Aggregation Level L = 2, each user's PDCCH includes two eCCEs. Therefore, the mapping relationship between the three users' eCCEs and the time-frequency resources is PDCCH. If mapping to the i-th unit of the first RB, it maps to up to mod (i + l, 3) units in the second RB, and mod (i + Mapping to up to a few units, i is a natural number greater than 0.

  As shown in FIG. 8, PDCCH of user 1 occupies unitl of the first RB, unit2 of the second RB, unit3 of the third RB, and PDCCH of user 2 is the first RB. occupying unit2, unit3 of 2nd RB, unitl of 3rd RB, PDCCH of user 3 uses unit3 of 1st RB, unitl of 2nd RB, unit2 of 3rd RB Private use. As can be seen, the total number of resources occupied by each user's PDCCH is 100.

  According to the method of the present embodiment, when Aggregation Level L> 2, for example, L = 4 or 8, the number of RBs corresponding to one PDCCH is larger than 3, and at this time, even if the above-described replacement scheme is repeated. Well, that is, three RBs are set as one cycle, and the three RBs are mapped in a circular manner.

  As in the embodiments of FIGS. 6 and 7, this embodiment is not limited to a specific circulation scheme or mapping pattern, and the number of resources occupied by each user's PDCCH is the same or almost the same. It only has to be guaranteed.

  With the PDCCH resource mapping scheme shown in FIG. 8, the number of resources distributed to each user's PDCCH is the same, so that it is possible to ensure that the performance of the PDCCH is not affected by the reference signal.

  FIG. 9 is a diagram showing PDCCH resource mapping in another embodiment of the present invention.

  Referring to FIG. 9, in the present embodiment, two users multiplex using one RB as an example. One RB is divided into two smaller resource sub-blocks, each numbered as unit 1-2, and each unit includes 6 sub-carriers. According to the method of this embodiment, based on the unit size, it is determined that one eCCE needs to correspond to one unit and needs to be mapped to different RBs. Let's take 2 units and map them to 2 RBs. In this embodiment, for the reference signal, it is assumed that the rank value that DM-RS can support is mnk = 2, and that CRS can support two antennas.

  According to the method of this embodiment, if Aggregation Level L = 2, each user's PDCCH includes two eCCEs. Therefore, the mapping relationship between the two users' eCCEs and the time-frequency resource is PDCCH. If mapping is performed on the i-th unit of the first RB, mapping is performed on up to the mod (i + l, 2) -th unit of the second RB. I is a natural number greater than 0.

  As shown in FIG. 9, the user 1 PDCCH occupies the first RB unitl and the second RB unit2, and the user 2 PDCCH occupies the first RB unit2 and the second RB. Use unitl. As can be seen, the number of resources occupied by each user's PDCCH is 100.

  According to the method of this embodiment, when Aggregation Level L> 2, for example, L = 4 or 8, the number of RBs corresponding to one PDCCH is larger than 2, and the above-described replacement scheme may be overlapped, that is, Two RBs are defined as one cycle, and the two RBs are mapped alternately.

  As in the embodiments of FIGS. 6, 7 and 8, this embodiment is not limited to a specific circulation scheme or mapping pattern, and the number of resources occupied by each user's PDCCH is the same or nearly the same. It only has to be guaranteed.

  With the PDCCH resource mapping scheme shown in FIG. 9, since the number of resources distributed to each user's PDCCH is the same, it can be guaranteed that the performance of the PDCCH is not affected by the reference signal.

  The present invention further provides a base station as described in the second embodiment, and the principle by which the base station solves the problem is similar to the resource mapping method of the downlink control channel of the first embodiment. Since the specific implementation can refer to the embodiment of the method of Embodiment 1, the description of the same process is omitted.

  An embodiment of the present invention provides a base station, which is used to perform resource mapping of a downlink control channel. FIG. 10 is a diagram showing a configuration of the base station. Referring to FIG. 10, the base station includes the following units.

  First determination unit 101: for determining the number of resource sub-blocks that a predetermined number of enhancement control channel elements (eCCE) need to correspond to based on the size of the resource sub-blocks in one resource block (RB) Used for.

  Second determining unit 102: used to determine the number of RBs to which the predetermined number of eCCEs need to be mapped based on the number of resource sub-blocks to which the predetermined number of eCCEs need to correspond.

  Mapping unit 103: used to map the eCCE of the downlink control channel (PDCCH) to the corresponding number of RBs based on the number of RBs to which the predetermined number of eCCEs need to be mapped. Among them, the resource sub-block corresponding to the eCCE in the PDCCH or a predetermined number of eCCEs has different positions in each RB.

  In one embodiment, the resource sub-block corresponding to the eCCE in the PDCCH or a predetermined number of eCCEs is cyclically moved in each RB.

In another embodiment, the position in each RB of the resource sub-block corresponding to the eCCE in the PDCCH or a predetermined number of eCCEs is set in advance.
In the above two embodiments, the mapping unit 103 further determines the cyclic scheme of the periodic cyclic shift based on the size of the eCCE or the size of the reference symbol overhead or aggregation level in the RB, or The preset position is determined, so that the number of resources occupied by each PDCCH is the same or substantially the same.

  In the above-described two embodiments, the mapping unit 103 further determines the cyclic mode of the cyclic circulation based on a predetermined strategy, or determines the preset position, whereby each PDCCH is The number of resources occupied is the same or almost the same.

  Since the number of resources occupied by each PDCCH is the same or substantially the same by the base station of this embodiment, the performance of the PDCCH can be optimized, and the influence of the reference signal on the PDCCH can be avoided.

  An embodiment of the present invention further provides a computer-readable program, and when executing the program in a base station, the program transmits the resource mapping method of the downlink control channel described in the first embodiment to the computer at the base station. Is executed.

  The embodiment of the present invention further provides a storage medium storing a computer-readable program, and the computer-readable program causes the computer to execute the resource mapping method of the downlink control channel described in the first embodiment in the base station.

  The above-described apparatus and method of the present invention may be realized by hardware, or may be realized by a combination of hardware and software. The present invention also relates to such a computer-readable program, that is, when the program is executed by the logic unit, the logic unit can realize the above-described apparatus or component. Alternatively, the above-described various methods or steps can be realized in the logic unit. The logic component is, for example, a field programmable logic component, a microprocessor, or a processor used in a computer. The present invention further relates to a storage medium storing the above-described program, for example, a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, a magnetic optical disk, a memory card, a memory stick, and the like.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and all modifications to the present invention belong to the technical scope of the present invention unless departing from the spirit of the present invention.

Claims (6)

A downlink control channel resource mapping method comprising:
Based on the size of the resource sub-block in one resource block (RB) and the number of resource elements required by one enhanced control channel element (eCCE), the resource sub-block that a predetermined number of eCCEs need to support Determine the number of
Determining the number of RBs to which the predetermined number of eCCEs need to be mapped based on the number of resource sub-blocks to which the predetermined number of eCCEs correspond; and the number of RBs to which the predetermined number of eCCEs need to be mapped Mapping eCCE of the downlink control channel (PDCCH) to RB based on
The position in each RB of the resource sub-block corresponding to the eCCE or a predetermined number of eCCEs in the PDCCH is different,
The position in each RB of the resource sub-block corresponding to the eCCE or a predetermined number of eCCEs in the PDCCH is preset,
The method wherein the preset position is determined based on a predetermined policy. The method of claim 1, comprising:
A method of determining the preset position based on a size of the eCCE or a size of a reference signal overhead or an aggregation level in the RB. A base station used to perform resource mapping of a downlink control channel,
Based on the size of the resource sub-block in one resource block (RB) and the number of resource elements required by one enhanced control channel element (eCCE), the resource sub-block that a predetermined number of eCCEs need to support A first determination unit for determining the number of
A second deterministic unit that determines the number of RBs to which the predetermined number of eCCEs need to be mapped based on the number of resource sub-blocks to which the predetermined number of eCCEs correspond; and the predetermined number of eCCEs that need to be mapped A mapping unit for mapping eCCEs of the downlink control channel (PDCCH) to RBs based on the number of RBs;
The position in each RB of the resource sub-block corresponding to the eCCE or a predetermined number of eCCEs in the PDCCH is different,
The position in each RB of the resource sub-block corresponding to the eCCE or a predetermined number of eCCEs in the PDCCH is preset,
The mapping unit is further a base station for determining the preset position based on a predetermined policy. The base station according to claim 3, wherein
The mapping unit further determines the preset position based on a size of the eCCE or a size of a reference signal overhead or an aggregation level in the RB. A computer readable program,
When the base station executes the program, the program causes a computer to execute the downlink control channel resource mapping method according to claim 1 or 2 at the base station. A storage medium storing a computer-readable program,
The computer-readable program causes a computer to execute the downlink control channel resource mapping method according to claim 1 or 2 at a base station.

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