The present disclosure relates to the field of wireless communications and particularly to a method of and apparatus for determining an orthogonal resource based on a virtual cell ID in a communication system based on Coordinated Multi-Point transmission/reception (CoMP).
There is an increased amount of information required to be fed back in the downlink, that is, there is an insufficient capacity of the uplink control channel, due to the introduction of downlink (DL) multi-point coordination technology to the LTE R11 system.
Firstly, compared to the existing network, channel information of a plurality of points is required to be fed back for multi-point coordination technology, while in the existing system channel information of only one point is required to be fed back, thus resulting in an increased demand for a feedback capacity. The introduction of CoMP and Heterogeneous Network (HTN) enables a larger number of user equipments to be supported in the same radio coverage area, so that there is a consequentially increased amount of feedback for Hybrid Automatic Repeat request (HARQ). Furthermore multi-point coordination technology can increase the capacity of data channel but can not increase the capacity of control channel because the modulation and encoding scheme of the control channel is fixed. Thus the improvement of channel quality fails to improve the channel capacity.
In the HTN network, the problem of channel interference can be addressed for the data channel due to multi-point coordination, but the performance of the control channel may be degraded greatly due to serious co-channel interference of a traditional single-point reception mode if this mode is still adopted for the control channel.
In CoMP scenario 4 (where a plurality of wireless reception points share a cell ID), a remote reception point can reuse part of orthogonal resources of the uplink control channel (PUCCH) for the gain of area splitting and the increased capacity of the uplink control channel.
In order to address the problem of the insufficient capacity of the uplink control channel due to the introduction of DL multi-point coordination technology to the LTE R11 system, two existing relevant technical solutions and their drawbacks are as follows:
In a first solution, orthogonal resources are allocated for user equipments in each macro cell or adjacent cell. This solution is suitable for use in the scenario 4 to thereby ensure the orthogonal resources for the respective user equipments. However the orthogonal resources may become insufficient because they have to be allocated for all the user equipments in the macro cell. This solution is not suitable for use in the scenario 3 because different cell IDs are adopted in respective cells to random a sequence, thus failing to ensure orthogonal resources to be allocated for user equipments in the different cells.
In a second solution, the user equipment is configured not to perform concurrent transmission over the control channel and the data channel such that information of the control channel will be incorporated onto the data channel for transmission, thus releasing part of the required capacity of the control channel. However, in the scenario with a large number of user equipments, the entire data channel is occupied by part of user equipments. Those user equipments for which the data channel is not allocated have to transmit over the control channel so that control information of other user equipments still have to compete for the limited control channel, thus restricting the capacity of the control channel.
It is therefore desirable to provide a technical solution which is suitable for the CoMP communication system, e.g., the CoMP scenario 3 and the CoMP scenario 4, and can achieve a tradeoff between the number of orthogonal resources and interference intensity.
In view of the foregoing concern, in an embodiment of the invention, there is provided a method, in a network control device of a CoMP communication system, of grouping a plurality of reception points. The method comprises the steps of: grouping the plurality of reception points into several clusters, wherein reception points in each cluster share a virtual cell ID; and transmitting a virtual cell ID corresponding to each reception point among the plurality of reception points respectively to the each reception point.
In another embodiment of the invention, there is provided a method, in a reception point of a communication system, of providing a user equipment with a virtual cell ID. The method comprises the steps of: receiving a virtual cell ID corresponding to the reception point from a network control device, the virtual cell ID being used for indicating a cluster for which the reception point belongs; providing the virtual cell ID to at least one user equipment served by the reception point; and transmitting resource index information corresponding to each user equipment among the at least one user equipment respectively to the each user equipment.
In a further embodiment of the invention, there is provided a method, in a user equipment of a communication system, of determining an orthogonal resource, the user equipment being served by a reception point. The method comprises the steps of: obtaining a virtual cell ID of the reception point; receiving resource index information corresponding to the present user equipment from the reception point; determining an orthogonal resource corresponding to the present user equipment according to the virtual cell ID and the resource index information; and transmitting uplink control information to the reception point over the determined orthogonal resource.
After a plurality of reception points are grouped into several clusters, for example according to location information and/or radio coverage areas of the plurality of reception points, wherein reception points in each cluster share a virtual cell ID, a virtual cell ID corresponding to each reception point among the plurality of reception points is transmitted respectively to the each reception point. Then each of these reception points provides its served user equipment with the corresponding virtual cell ID in the following method steps: the reception point firstly receives a virtual cell ID corresponding to the reception point from a network control device and further provides the virtual cell ID to at least one user equipment served by the reception point, and then transmits resource index information corresponding to each user equipment among the at least one user equipment respectively to the each user equipment. The served user equipment obtains the corresponding virtual cell ID and the corresponding resource index information thereof and then determines an orthogonal resource corresponding to the present user equipment according to the virtual cell ID and the resource index information and transmits uplink control information to the reception point over the determined orthogonal resource. At this point, the entire process of determining the orthogonal resource based on the virtual cell ID in a CoMP communication in the field of wireless communications has been finished.
The tradeoff between the number of orthogonal resources and interference intensity can be achieved in the methods according to the embodiments of the invention.
In an embodiment of the invention, there is provided an apparatus, in a network control device of a communication system based on coordinated multi-point transmission, for grouping a plurality of reception points. The apparatus comprises: a grouping device configured to group the plurality of reception points into several clusters, wherein reception points in each cluster share a virtual cell ID; and a first transmitting device configured to transmit a virtual cell ID corresponding to each reception point among the plurality of reception points respectively to the each reception point.
In another embodiment of the invention, there is provided an apparatus, in a reception point of a communication system, for providing a user equipment with a virtual cell ID. The apparatus comprises: a first receiving device configured to receive a virtual cell ID corresponding to the reception point from a network control device, the virtual cell ID being used for indicating a cluster to which the reception point belongs; a providing device configured to provide the virtual cell ID to at least one user equipment served by the reception point; and a second transmitting device configured to transmit resource index information corresponding to each user equipment among the at least one user equipment respectively to the each user equipment.
In a further embodiment of the invention, there is provided an apparatus, in a user equipment of a communication system, for determining an orthogonal resource, the user equipment being served by a reception point. The apparatus comprises: an obtaining device configured to obtain a virtual cell ID of the reception point; a second receiving device configured to receive resource index information corresponding to the present user equipment from the reception point; a determining device configured to determine an orthogonal resource corresponding to the present user equipment according to the virtual cell ID and the resource index information; and a third transmitting device configured to transmit uplink control information to the reception point over the determined orthogonal resource.
The foregoing and other features of the invention will become more apparent from the foregoing detailed description of embodiments illustrated with reference to the drawings in which identical reference numerals denote identical or like components:
In the figure, there are illustrated six reception points, i.e., a reception point 1, a reception point 2, a reception point 3, a reception point 4, a reception point 5 and a reception point 6, wherein the reception point 1, the reception point 2 and the reception point are adjacent to each other in geographical location, and the reception point 4, the reception point 5 and the reception point 6 are adjacent to each other in geographical location. It shall be noted that the six reception points illustrated in
In the invention, the network control device firstly groups the six reception points, for example according to their location information and/or radio coverage areas, that is, groups the six reception points into several clusters according to geographical locations and/or radio coverage areas. For example, as illustrated in
The network control device transmits the virtual cell ID corresponding to each reception point among the six reception points respectively to the each reception point after grouping the six reception points into several clusters.
The following description will be given respectively from the perspective of a reception point in a cluster obtaining a virtual cell ID from a network control device and providing it to a user equipment and the perspective of a user equipment determining an orthogonal resource based on a virtual cell ID.
Firstly the reception point receives the virtual cell ID corresponding to the reception point from the network control device in the step S201.
Secondly the reception point provides the virtual cell ID to at least one user equipment served by the reception point in the step S202.
Specifically the reception point can provide the virtual cell ID to at least one user equipment served by the reception point in numerous ways.
For example, an RRC signaling can be newly defined in the invention. Then the reception point can provide the virtual cell ID to at least one user equipment served by the reception point via the RRC signaling.
In another example, a reference signal port-to-virtual cell ID mapping table can be stored at the user equipment side. The reference signal port-to-virtual cell ID mapping table can be one-to-one or multiple-to-one. After the reception point transmits to the user equipment the reference signal port information corresponding to the user equipment, the user equipment can search the stored port-to-virtual cell ID mapping table for the corresponding virtual cell ID according to the received reference signal port information. When the user equipment is allocated a plurality of reference signal ports, the user equipment can take the first one in the received sequence of reference signal ports as the reference value indicating the virtual cell ID and search the stored port-to-virtual cell ID mapping table for the corresponding virtual cell ID based on the reference value. It shall be noted that when the user equipment is allocated a plurality of reference signal ports, the user equipment can alternatively take any other one in the received sequence of reference signal ports as the reference value indicating the virtual cell ID, as agreed in advance. For example, it can be agreed in advance to take a second one in the received sequence of reference signal ports as the reference value indicating the virtual cell ID.
The extra signaling overhead can be saved by providing virtual cell ID information in this way.
Finally the reception point transmits resource index information corresponding to each user equipment among the at least one user equipment respectively to the each user equipment in the step S203.
Firstly the user equipment obtains the virtual cell ID of the reception point in the step S301.
Again the user equipment can obtain the virtual cell ID of the reception point in numerous ways.
For example, the user equipment receives from the reception point the virtual cell ID transmitted via an RRC signaling as described in
In another example, a reference signal port-to-virtual cell ID mapping table can be stored at the user equipment side. The reference signal port-to-virtual cell ID mapping table can be one-to-one or multiple-to-one. After the reception point transmits to the user equipment the reference signal port information corresponding to the user equipment, the user equipment can search the stored port-to-virtual cell ID mapping table for the corresponding virtual cell ID according to the received reference signal port information. When the user equipment is allocated a plurality of reference signal ports, the user equipment can take the first one in the received sequence of reference signal ports as the reference value indicating the virtual cell ID and search the stored port-to-virtual cell ID mapping table for the corresponding virtual cell ID based on the reference value.
Then the user equipment receives resource index information corresponding to the present user equipment from the reception point in the step S302.
Next the user equipment determines an orthogonal resource corresponding to the present user equipment according to the obtained virtual cell ID and the received resource index information in the step S303.
Finally the user equipment transmits Uplink Control Information (UCI) to the reception point over the determined orthogonal resource in the step S304.
The technical solution of the invention has been described above from the perspective of methods and will be further described below from the perspective of apparatuses.
In an embodiment of the invention, there is provided an apparatus, in a network control device of a communication system based on coordinated multi-point transmission, for grouping a plurality of reception points. The apparatus comprises:
a grouping device configured to group the plurality of reception points into several clusters, wherein reception points in each cluster share a virtual cell ID; and
a first transmitting device configured to transmit a virtual cell ID corresponding to each reception point among the plurality of reception points respectively to the each reception point.
In another embodiment of the invention, there is provided an apparatus, in a reception point of a communication system, for providing a user equipment with a virtual cell ID. The apparatus comprises:
a first receiving device configured to receive a virtual cell ID corresponding to the reception point from a network control device, the virtual cell ID being used for indicating a cluster to which the reception point belongs;
a providing device configured to provide the virtual cell ID to at least one user equipment served by the reception point; and
a second transmitting device configured to transmit resource index information corresponding to each user equipment among the at least one user equipment respectively to the each user equipment.
In a further embodiment of the invention, there is provided an apparatus, in a user equipment of a communication system, for determining an orthogonal resource, the user equipment being served by a reception point. The apparatus comprises:
an obtaining device configured to obtain a virtual cell ID of the reception point;
a second receiving device configured to receive resource index information corresponding to the present user equipment from the reception point;
a determining device configured to determine an orthogonal resource corresponding to the present user equipment according to the virtual cell ID and the resource index information; and
a third transmitting device configured to transmit uplink control information to the reception point over the determined orthogonal resource.
Moreover the embodiments of the invention can be embodied in software, hardware or combination of software and hardware. The part of hardware can be embodied in a dedicated logic, and the part of software can be stored in a memory and performed by an appropriate instruction execution system, for example, a microprocessor or specially designed hardware. Those ordinarily skilled in the art can appreciate the foregoing methods and systems can be embodied in computer executable instructions and/or included in processor control codes, for example, such codes are carried in a carrier medium, e.g., a magnetic disk, a CD or a DVD-ROM, a programmable memory, e.g., a read only memory (firmware), or a data carrier, e.g., an optical or electronic signal carrier. The systems and the components thereof of the embodiments can be embodied in, for example, a very large scale integrated circuit or a gate array, a semiconductor, e.g., a logic chip, a transistor, etc., or a programmable hardware device, e.g., a field programmable gate array, a programmable logic device, etc., in software performed by variety of processor or in combination of the foregoing hardware circuit and software, e.g., in firmware.
Although the invention has been described in connection with the embodiments conceived so far, it shall be appreciated that the invention will not be limited to the disclosed embodiments. On the contrary, the invention is intended to encompass various modifications and equivalent arrangements falling into the sprit and scope of the appended claims. The appended claims shall be accorded the broadcast interpretations so as to encompass all these modifications as well as equivalent structures and functions.
Number | Date | Country | Kind |
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201110296400.8 | Sep 2011 | CN | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2012/002170 | 9/21/2012 | WO | 00 | 3/19/2014 |