The present invention relates to transmission technologies in a communication system, and particularly, to an LTE-A heterogeneous network system; a mobile terminal, a micro base station and a macro base station in the LTE-A heterogeneous network system; and methods used in the mobile terminal, the micro base station and the macro base station.
The Long Term Evolution (LTE) of the 3GPP continues to use the traditional homogeneous network which is constructed by a hexagonal cellular system. In order to further improve the system capacity, the next generation wireless communication system, the Advanced LTE (LTE-A), introduces the heterogeneous network. The LTE-A system may be composed of a macro cell, a femto cell, a pico cell, a Remote Radio Head (RRH) and a relay. By deploying new wireless nodes, the LTE-A system not only improves the system capacity, but also provides better services to the users of special areas and optimizes the system performance. However, the deployment of the new nodes causes interferences to the users of the originally deployed cells, and even covers some holes. Therefore, an enhanced Inter-Cell Interference Coordination (eICIC) method is required to further optimize the system performance.
Under the macro cell and micro cell (including femto cell, pico cell, RRH, relay, etc.) mixed cell scenario, in order to improve the cell capacity, the cell extension technology is adopted.
In order to support the operation of the ABS, two measurement subsets are defined. One of the subsets is used to measure the interference information of corresponding ABS, and the other subset is used to measure the interference information of corresponding non-ABS. The user terminal feeds back corresponding channel status information on the configured measurement subset.
In the studying process of different embodiments herein, the inventor finds that although the conventional ABS method can reduce the interference on the signal transmitted by the base station of the micro cell from the signal transmitted by the base station of the macro cell, the disadvantage is that no more help can be given to the service provided by the micro cell while the macro cell resources are idle, i.e., it only achieves noninterference, without making any contribution to the improvement of the service of the micro cell.
Certain embodiments are proposed with respect to the above condition of the prior art, so as to overcome or relieve one or more shortages of the prior art.
According to an aspect of certain embodiments, a communication method used in a mobile terminal is provided, comprising the steps of: receiving from a micro base station a designation of specific subframe and a designation of feedback mode; judging whether a current subframe is a specific subframe designated by the micro base station; measuring and feeding back the channel condition of the current subframe in a joint transmission feedback mode when the current subframe is the specific subframe designated by the micro base station, and measuring and feeding back the channel condition of the current subframe in a feedback mode designated by the micro base station when the current subframe is not the specific subframe designated by the micro base station.
According to another aspect, a mobile terminal is provided, comprising: a receiving unit configured to receive from a micro base station a designation of specific subframe and a designation of feedback mode; a judging unit configured to judge whether a current subframe is a specific subframe designated by the micro base station; and a feeding back unit configured to measure and feed back the channel condition of the current subframe in a joint transmission feedback mode when the current subframe is the specific subframe designated by the micro base station, and measure and feed back the channel condition of the current subframe in a feedback mode designated by the micro base station when the current subframe is not the specific subframe designated by the micro base station.
According to another aspect, a method used in a micro base station is provided, comprising the steps of: receiving from a macro base station information about Almost Blank Subframe (ABS) allocated to the macro base station; designating a feedback mode, and designating a subframe used by the micro base station and corresponding to the ABS as a specific subframe; transmitting information about the specific subframe and the feedback mode to a mobile terminal, transmitting data to the mobile terminal in the specific subframe, and transmitting to the macro base station data to be transmitted by the macro base station to the mobile terminal in the ABS and a location of the data in the ABS; processing the channel feedback information as channel feedback information in a joint transmission feedback mode when the received channel feedback information is for the specific subframe, and processing the channel feedback information as channel feedback information in a feedback mode designated by the designating when the received channel feedback information is not for the specific subframe.
According to another aspect, a micro base station is provided, comprising: a receiving unit configured to receive from a macro base station information about ABS allocated to the macro base station, and receive channel feedback information from a mobile terminal; a designating unit configured to designate a feedback mode, and designate a subframe used by the micro base station and corresponding to the ABS as a specific subframe; a transmitting unit configured to transmit information about the specific subframe and the feedback mode to the mobile terminal, transmit data to the mobile terminal in the specific subframe, and transmit to the macro base station data to be transmitted by the macro base station to the mobile terminal in the ABS and a location of the data in the ABS; a feedback processing unit configured to process the channel feedback information as channel feedback information in a joint transmission feedback mode when the received channel feedback information is for the specific subframe, and process the channel feedback information as channel feedback information in a feedback mode designated by the designating unit when the received channel feedback information is not for the specific subframe.
According to another aspect, a macro base station is provided, comprising: a first transmitting unit configured to transmit information about ABS to a micro base station; a receiving unit configured to receive from the micro base station data and information about a location of the data in the ABS; and a second transmitting unit configured to transmit the data received by the receiving unit in the ABS according to the location designated by the information about the location received by the receiving unit.
According to another aspect, a communication system is provided, comprising the aforementioned mobile terminal, micro base station and macro base station.
The above general descriptions and the following detailed descriptions made with reference to the drawings are all schematic, rather than limitations to the protection scope of the present invention.
The above and other objects, characteristics and advantages of certain embodiments will be understood more clearly through the following detailed descriptions made with reference to the drawings.
Several embodiments herein are detailedly described as follows with reference to the drawings. To be noted, features described and/or illustrated with respect to one embodiment may be used in the same or similar way in one or more other embodiments, combined with or in substitution of the features in other embodiments.
To be emphasized, the term “comprise/include” and “comprising/including” used herein specifies the presence of feature, integer, step or component, not excluding the presence or addition of one or more other features, integers, steps or components.
Several embodiments herein are applicable to the heterogeneous network, where a large cell includes one or more small cells. The large cell is referred to as the macro cell, and the small cell is referred to as the micro cell. The micro cell for example may be a femto cell, a pico cell, an RRH, a relay, etc. The base station used in the micro cell is referred to as the micro base station, and the base station used in the macro cell is referred to as the macro base station. The communication system to which the embodiment is applicable for example is illustrated in
As illustrated in
In one embodiment, the feedback mode may be a joint transmission feedback mode for the multi-point cooperation joint transmission, a coordinative scheduling/coordinative beam forming (CS/CB) feedback mode for the multi-point cooperation CS/CB mode, or a non-multi-point cooperation transmission feedback mode for the non-multi-point cooperation transmission.
To be noted, the above descriptions are just schematic, and a person skilled in the art shall appreciate that the order of the above steps can be adjusted, and some steps may be performed concurrently.
The mobile phone 10 may include a display 14 that displays information such as operating state, time, telephone number, telephone directory, menus, etc. to the user, so that the user can utilize various features of the electronic device 10. The display 14 may be further configured to visually display the content received by the electronic device 10 and/or retrieved from a memory (not illustrated) of the mobile phone 10. The display 14 may be configured to present images, videos and other graphics (e.g., photos, mobile TV programs and game-related videos) to the user.
A keypad 18 provides multiple user input operations. For example, the keypad 18 may include alphanumeric keys that allow alphanumerical information (e.g., telephone number, telephone list, telephone directory, notepad, text, etc.) to be input. In addition, the keypad 18 may include specific function keys 17, such as a “call send” key for initiating or answering a phone call, and a “call end” key for ending or hanging up the phone call. The specific function keys may further include a menu navigation key and a selection key which conveniently perform navigation through menus displayed on the display 14. For example, a pointing device and/or a navigation key may be provided to receive a directional input from the user. In addition, the display 14 and the keypad 18 may be used in combination to realize the soft key function. The mobile phone 10 further includes parts essential for realizing its functions, such as an antenna, a microcontroller, a speaker 50 and a microphone 52.
As illustrated in
In addition, the receiving unit receives data from both the macro base station and the micro base station at the specific subframe designated by the micro base station, according to the control information received from the micro base station.
The receiving unit 601 receives from a macro base station information about ABS allocated to the macro base station, and receives channel feedback information from a mobile terminal.
The designating unit 602 designates a feedback mode, and designates a subframe used by the micro base station and corresponding to the ABS as a specific subframe.
The transmitting unit 603 transmits information about the specific subframe and the feedback mode to the mobile terminal, and transmits to the macro base station data to be transmitted by the macro base station to the mobile terminal in the ABS and a location of the data in the ABS. In the specific subframe, the transmitting unit further transmits to the mobile terminal the data the same as those transmitted to the macro base station.
The feedback processing unit 604 processes the channel feedback information as channel feedback information in a joint transmission feedback mode when the channel feedback information received by the receiving unit 601 from the mobile terminal is for the specific subframe, and processes the channel feedback information as channel feedback information in a feedback mode designated by the designating unit when the channel feedback information received by the receiving unit 601 is not for the specific subframe.
The first transmitting unit 701 transmits information about ABS to a micro base station; the receiving unit 702 receives, from the micro base station, data to be transmitted to the mobile station and information about a location of the data in the ABS; and the second transmitting unit 703 transmits, in the ABS according to a location designated by the information about the location of the data in the ABS received by the receiving unit, the data received by the receiving unit.
The operation in
In another embodiment, the micro base station may transmit activation information to the mobile terminal. For example, the specific flag bit may be set as 1 or 0 by appointment. For example, only when the specific flag bit is set as 1 by appointment, i.e., the activation information indicates an effective value, the mobile terminal performs the judgment in step S803. When the specific flag bit is set as 0 by appointment, i.e., the activation information indicates an ineffective value, the mobile terminal performs measurement and feedback in the feedback mode designated by the micro base station. Herein 0 and 1 are exemplary and other values may be appointed.
In one embodiment, the micro base station may determine the activation information to be transmitted according to whether the mobile terminal is located in a cell extension region. When the mobile terminal is located in the cell extension region, activation information indicating an effective value is transmitted; and when the mobile terminal is not located in the cell extension region, activation information indicating an ineffective value is transmitted.
In several embodiments, in non-ABS, the mobile station operates in the conventional CoMP mode, and the mobile terminal may operate in the JP mode or the CS/CB mode. The micro base station configures the CoMP operation mode for the mobile station. In ABS (in some embodiments, when the activation information indicates an effective value), the mobile station feeds back in the JP mode in measurement set 2, including PMI/CQI information, no matter how the micro base station configures the CoMP operation mode for the mobile station. In non-ABS, the mobile station feeds back in the CoMP operation mode configured by the system in measurement set 1.
Among the descriptions of several embodiments, the descriptions of the methods and steps may be taken to help the understanding of the devices and units, and the descriptions of the devices and units may be taken to help the understanding of the method and steps.
The above devices and methods may be implemented by hardware, or a combination of hardware and software. The present invention relates to a logic part readable program which when being executed by a logic part, enables the logic part to implement the aforementioned device or constituent parts, or enables the logic part to implement the aforementioned methods or steps. The logic part for example may be a field programmable logic part, a microprocessor, a processor used in the computer, etc. The several embodiments further relate to a storage medium for storing the above program, such as hard disc, magnetic disc, optical disc, DVD, flash, magnetic optical disc, memory card, memory stick, etc.
The present invention is described as above in conjunction with specific embodiments. But a person skilled in the art shall appreciate that those descriptions are just exemplary, rather than limitations to the protection scope of the present invention. A person skilled in the art can make various modifications and changes to the present invention based on the spirit and the principle of the present invention, and those modifications and changes also fall within the scope of the present invention.
This application is a continuation of International Application PCT/CN2011/070974, filed Feb. 14, 2011 and now pending, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2011/070974 | Feb 2011 | US |
Child | 13955729 | US |