Abstract:
A system includes a base station (BS) and a user equipment (UE). The BS is capable of communicating with the UE via a serving cell and a coordinated cell. The BS includes a frequency exchange module coupled with a first baseband processing unit and a second baseband processing unit. The first baseband processing unit is designated for supporting baseband processing related to the coordinated cell, and the second baseband processing unit is designated for supporting baseband processing related to the serving cell. The frequency exchange module is configured to forward a first frequency domain signal to the second baseband processing unit according to a first predetermined coordination configuration relating to the serving cell of the UE and the coordinated cell of the UE. The second baseband processing unit is configured to perform a joint processing of the first frequency domain signal and a second frequency domain signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application No. PCT/CN2011/082970, filed on Nov. 25, 2011, which is hereby incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to the field of communications technologies, and particularly to a system, a base station, and a method of facilitating processing of a signal sent by a user equipment to a base station. 
       BACKGROUND 
       [0003]    In a long term evolution-advanced (LTE-A) system, coverage of a high data rate may be expanded, throughput of a cell edge may be improved and/or system throughput may be improved by using a coordinated multi-point transmission/reception (CoMP) technology. The so-called CoMP means that multiple transmission points (which may be understood as different cells) geographically separated from each other participate in transmitting data to or receiving data from one user equipment (UE) in coordination. 
         [0004]    The CoMP may be classified into downlink CoMP and uplink CoMP. The downlink CoMP means that multiple cells directly or indirectly participate in sending downlink data to the same UE; and the uplink CoMP means that multiple cells receive uplink data from the same UE. The downlink CoMP is classified into joint processing and coordinated scheduling. A joint processing manner may further be classified into joint transmission and dynamic cell selection. The joint transmission means that multiple cells transmit data to one UE at the same time on a physical downlink shared channel (PDSCH), so as to improve the quality of a signal received by the UE and/or eliminate interference from other UEs. The dynamic cell selection means that only one cell sends data to a UE at each time point, and the cell may be dynamically selected from a CoMP cooperating set. In a coordinated scheduling manner, only a serving cell performs scheduling and transmission on the UE, and mutual interference among different UEs is avoided through coordination of resources such as time, frequency, power and space among cells. 
       SUMMARY 
       [0005]    According to a first aspect, a system is provided. The system includes a base station (BS) and a user equipment (UE). The BS is capable of communicating with the UE via a serving cell and a coordinated cell. The BS includes a frequency exchange module coupled with a first baseband processing unit and a second baseband processing unit. The first baseband processing unit is designated for supporting baseband processing related to the coordinated cell, and the second baseband processing unit is designated for supporting baseband processing related to the serving cell. The frequency exchange module is configured to: receive a first frequency domain signal from the first baseband processing unit, the first frequency domain signal being derived from a signal sent by the UE; and determine to forward the first frequency domain signal to the second baseband processing unit according to a first predetermined coordination configuration relating to the serving cell of the UE and the coordinated cell of the UE. The second baseband processing unit is configured to: generate a second frequency domain signal being derived from the signal sent by the UE; receive the first frequency domain signal; and perform a joint processing of the first frequency domain signal and the second frequency domain signal. 
         [0006]    According to a second aspect, a base station (BS) is provided. The BS is capable of communicating with a user equipment (UE) via a serving cell and a coordinated cell. The BS includes a frequency exchange module coupled with a first baseband processing unit and a second baseband processing unit. The first baseband processing unit is designated for supporting baseband processing related to the coordinated cell, and the second baseband processing unit is designated for supporting baseband processing related to the serving cell. The frequency exchange module is configured to: receive a first frequency domain signal from the first baseband processing unit, the first frequency domain signal being derived from a signal sent by the UE; and determine to forward the first frequency domain signal to the second baseband processing unit according to a first predetermined coordination configuration relating to the serving cell of the UE and the coordinated cell of the UE. The second baseband processing unit is configured to: generate a second frequency domain signal being derived from the signal sent by the UE; receive the first frequency domain signal; and perform a joint processing of the first frequency domain signal and the second frequency domain signal. 
         [0007]    According to a third aspect, a method of facilitating processing of a signal sent by a user equipment (UE) to a base station (BS) is provide. The BS is capable of communicating with the UE via a serving cell and a coordinated cell. The BS includes a frequency exchange module coupled with a first baseband processing unit and a second baseband processing unit. The first baseband processing unit is designated for supporting baseband processing related to the coordinated cell, and the second baseband processing unit is designated for supporting baseband processing related to the serving cell. The frequency exchange module receives a first frequency domain signal from the first baseband processing unit, the first frequency domain signal being derived from a signal sent by the UE; and determine to forward the first frequency domain signal to the second baseband processing unit according to a first predetermined coordination configuration relating to the serving cell of the UE and the coordinated cell of the UE. The second baseband processing unit generates a second frequency domain signal being derived from the signal sent by the UE; and performs a joint processing of the first frequency domain signal and the second frequency domain signal. 
         [0008]    These and other aspects of the invention will be apparent from the embodiments described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a flow chart of a signal sending method according to an embodiment of the present invention; 
           [0010]      FIG. 2  is a schematic diagram of an application scenario according to an embodiment of the present invention; 
           [0011]      FIG. 3  is a flow chart of a signal sending method according to another embodiment of the present invention; 
           [0012]      FIG. 4  is a schematic diagram of an application scenario according to another embodiment of the present invention; 
           [0013]      FIG. 5  is a flow chart of a signal sending method according to another embodiment of the present invention; 
           [0014]      FIG. 6  is a schematic diagram of an application scenario according to another embodiment of the present invention; 
           [0015]      FIG. 7  is a schematic diagram of an application scenario according to another embodiment of the present invention; 
           [0016]      FIG. 8  is a flow chart of a signal sending method according to another embodiment of the present invention; 
           [0017]      FIG. 9  is a schematic diagram of an application scenario according to another embodiment of the present invention; 
           [0018]      FIG. 10  is a flow chart of a signal sending method according to another embodiment of the present invention; 
           [0019]      FIG. 11  is a schematic diagram of an application scenario according to another embodiment of the present invention; 
           [0020]      FIG. 12  is a schematic diagram of an application scenario according to another embodiment of the present invention; 
           [0021]      FIG. 13  is a schematic structural diagram of a base station device according to an embodiment of the present invention; 
           [0022]      FIG. 14  is a schematic structural diagram of a base station device according to another embodiment of the present invention; 
           [0023]      FIG. 15  is a schematic structural diagram of a base station device according to another embodiment of the present invention; 
           [0024]      FIG. 16  is a schematic structural diagram of a base station device according to another embodiment of the present invention; 
           [0025]      FIG. 17  is a schematic structural diagram of a base station device according to another embodiment of the present invention; 
           [0026]      FIG. 18  is a schematic structural diagram of a base station device according to another embodiment of the present invention; 
           [0027]      FIG. 19  is a schematic structural diagram of a base station device according to another embodiment of the present invention; 
           [0028]      FIG. 20  is a schematic structural diagram of a base station device according to another embodiment of the present invention; 
           [0029]      FIG. 21  is a schematic structural diagram of a base station device according to another embodiment of the present invention; 
           [0030]      FIG. 22  is a schematic structural diagram of a base station device according to another embodiment of the present invention; and 
           [0031]      FIG. 23  is a schematic structural diagram of a base station device according to another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0032]      FIG. 1  is a flow chart of a signal sending method according to an embodiment of the present invention. The signal sending method provided in this embodiment may be applied in a base station device that includes a frequency domain exchange module and at least two baseband processing units, and the frequency domain exchange module is connected to each of the at least two baseband processing units. 
         [0033]    As shown in  FIG. 1 , the signal sending method may include: 
         [0034]    Step  101 : The frequency domain exchange module receives a first frequency domain signal of a first user equipment, where the first frequency domain signal is obtained from at least one coordinated cell of the first user equipment and is sent by a baseband processing unit of the at least two baseband processing units, where the baseband processing unit corresponds to the at least one coordinated cell of the first user equipment. 
         [0035]    The first frequency domain signal is obtained by performing a time-frequency transformation on a first time domain signal, after a baseband processing unit that corresponds to the at least one coordinated cell of the first user equipment receives the first time domain signal that is sent by the first user equipment through a radio frequency channel of the at least one coordinated cell of the first user equipment. 
         [0036]    Specifically, the baseband processing unit that corresponds to the at least one coordinated cell of the first user equipment may perform a fast Fourier transformation (Fast Fourier Transformation, herein after referred to as FFT) and a de-mapping processing on the first time domain signal, and obtain a first frequency domain signal of the first user equipment in the at least one coordinated cell according to high-layer configuration information, where the high-layer configuration information includes a sub-carrier that is configured by a high layer (for example, a base station controller) and is used when the first user equipment sends data. 
         [0037]    In this embodiment, when CoMP is performed, at least two cells participate in transmitting data to or receiving data from a user equipment in coordination. The at least two cells are coordinated cells for each other. For the first user equipment, at least one cell of the at least two cells other than a serving cell of the first user equipment is at least one coordinated cell of the first user equipment. Such details are not repeated in other embodiments for conciseness consideration. 
         [0038]    Step  102 : The frequency domain exchange module sends the first frequency domain signal to a first baseband processing unit of the at least two baseband processing units, where the first baseband processing unit corresponds to a serving cell of the first user equipment, so that the first baseband processing unit performs a joint processing on the first frequency domain signal and a second frequency domain signal of the first user equipment, where the second frequency domain signal is obtained from the serving cell of the first user equipment by the first baseband processing unit. 
         [0039]    The second frequency domain signal is obtained by performing a time-frequency transformation on a second time domain signal, after the first baseband processing unit receives the second time domain signal that is sent by the first user equipment through a radio frequency channel of the serving cell of the first user equipment. 
         [0040]    Specifically, the first baseband processing unit may perform an FFT and a de-mapping processing on the second time domain signal, and obtain a second frequency domain signal of the first user equipment in the serving cell according to high-layer configuration information, where the high-layer configuration information includes a sub-carrier that is configured by a high layer (for example, a base station controller) and is used when the first user equipment sends data. 
         [0041]    In the foregoing embodiment, after a frequency domain exchange module receives a first frequency domain signal of a first user equipment, where the first frequency domain signal is obtained from at least one coordinated cell of the first user equipment and is sent by a baseband processing unit of at least two baseband processing units that are connected to the frequency domain exchange module, where the baseband processing unit corresponds to the at least one coordinated cell of the first user equipment, the frequency domain exchange module sends the first frequency domain signal to a first baseband processing unit of the at least two baseband processing units, where the first baseband processing unit corresponds to a serving cell of the first user equipment, so that the first baseband processing unit performs a joint processing of the first frequency domain signal and a second frequency domain signal of the first user equipment, where the second frequency domain signal is obtained from the serving cell of the first user equipment by the first baseband processing unit. In this way, data exchange between a serving cell and a coordinated cell in an LTE-A system can be implemented, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0042]    The method provided in the embodiment shown in  FIG. 1  of the present invention may be applied in a scenario shown in  FIG. 2 , and  FIG. 2  is a schematic diagram of an application scenario according to an embodiment of the present invention. 
         [0043]    In  FIG. 2 , cell  1  (Cell 1 ) and cell  2  (Cell 2 ) are coordinated cells for each other, a serving cell of UE  1  is cell  1  and a coordinated cell of UE  1  is cell  2 .  FIG. 2  is shown by using an example that a base station device includes a frequency domain exchange module and two baseband processing units, where the frequency domain exchange module is connected to each of the two baseband processing units. A first baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to cell  1 ; and a second baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to at least one coordinated cell of UE  1 , that is, a baseband processing unit that corresponds to cell  2 . 
         [0044]      FIG. 3  is a flow chart of a signal sending method according to another embodiment of the present invention, and this embodiment is described by taking a CoMP process of UE  1  in  FIG. 2  as an example. 
         [0045]    As shown in  FIG. 3 , the signal sending method may include: 
         [0046]    Step  301 : A second baseband processing unit receives a first time domain signal that is sent by UE  1  through a radio frequency channel of cell  2 , and performs a time-frequency transformation on the first time domain signal to obtain a first frequency domain signal of UE  1  in cell  2 . 
         [0047]    The second baseband processing unit may perform an FFT and a de-mapping processing on the first time domain signal, and obtain a first frequency domain signal of a first user equipment in cell  2  according to high-layer configuration information, where the high-layer configuration information includes a sub-carrier that is configured by a high layer (for example, a base station controller) and is used when UE  1  sends data. 
         [0048]    Step  302 : A first baseband processing unit receives a second time domain signal that is sent by UE  1  through a radio frequency channel of cell  1 , and performs time-frequency transformation on the second time domain signal to obtain a second frequency domain signal of UE  1  in cell  1 . 
         [0049]    The first baseband processing unit may perform an FFT and a de-mapping processing on the second time domain signal, and obtain a second frequency domain signal of the first user equipment in cell  1  according to high-layer configuration information, where the high-layer configuration information includes a sub-carrier that is configured by a high layer (for example, a base station controller) and is used when UE  1  sends data. 
         [0050]    Step  303 : The second baseband processing unit sends the first frequency domain signal to a frequency domain exchange module. 
         [0051]    Step  304 : The frequency domain exchange module sends the first frequency domain signal to the first baseband processing unit. 
         [0052]    Specifically, a sending route of the frequency domain exchange module is configured by a high layer (for example, a base station controller) according to a CoMP coordination relationship. In this embodiment, the sending route of the frequency domain exchange module is specifically that the frequency domain exchange module sends the first frequency domain signal to the first baseband processing unit. 
         [0053]    Step  305 : The first baseband processing unit performs a joint processing on the first frequency domain signal and the second frequency domain signal. 
         [0054]    For example, the first baseband processing unit may first perform a multiple input multiple output (Multiple Input Multiple Output, hereinafter referred to as MIMO) decoding and an equalization processing on the first frequency domain signal and the second frequency domain signal, and then perform a processing such as an inverse discrete Fourier transform (Inverse Discrete Fourier Transform, hereinafter referred to as IDFT)/demodulation/de-interleaving/hybrid automatic repeat request (Hybrid Automatic Repeat Request, hereinafter referred to as HARQ) combination/decoding/cyclic redundancy check (Cyclic Redundancy Check, hereinafter referred to as CRC). 
         [0055]    Through the foregoing embodiment, data exchange between a serving cell and a coordinated cell in an LTE-A system can be implemented, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0056]    In an implementation manner of the embodiment shown in  FIG. 1  of the present invention, the first time domain signal is sent by a time domain exchange module that is connected to at least two baseband processing units to a baseband processing unit that corresponds to at least one coordinated cell of the first user equipment, after the time domain exchange module receives the first time domain signal that is sent by the first user equipment through a radio frequency channel of the at least one coordinated cell of the first user equipment. The second time domain signal is sent by the time domain exchange module that is connected to the at least two baseband processing units to the first baseband processing unit, after the time domain exchange module receives the second time domain signal that is sent by the first user equipment through a radio frequency channel of a serving cell of the first user equipment. 
         [0057]    That is to say, through the time domain exchange module, the second time domain signal that is sent by the first user equipment through the radio frequency channel of the serving cell of the first user equipment and the first time domain signal that is sent by the first user equipment through the radio frequency channel of the at least one coordinated cell of the first user equipment may be sent respectively to the first baseband processing unit and the baseband processing unit that corresponds to the at least one coordinated cell of the first user equipment. 
         [0058]      FIG. 4  is a schematic diagram of an application scenario according to another embodiment of the present invention. In  FIG. 4 , cell  1  and cell  2  are coordinated cells for each other, a serving cell of UE  1  is cell  1 , and a coordinated cell of UE  1  is cell  2 .  FIG. 4  is shown by using an example that a base station device includes a frequency domain exchange module, a time domain exchange module, and two baseband processing units, where the frequency domain exchange module is connected to each of the two baseband processing units, and the time domain exchange module is connected to each of the two baseband processing units. A first baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to cell  1 ; and a second baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to at least one coordinated cell of UE  1 , that is, a baseband processing unit that corresponds to cell  2 . 
         [0059]      FIG. 5  is a flow chart of a signal sending method according to another embodiment of the present invention, and this embodiment is described by taking a CoMP process of UE  1  in  FIG. 4  as an example. 
         [0060]    As shown in  FIG. 5 , the signal sending method may include: 
         [0061]    Step  501 : A time domain exchange module receives a second time domain signal that is sent by UE  1  through a radio frequency channel of cell  1  and a first time domain signal that is sent by UE  1  through a radio frequency channel of cell  2 . 
         [0062]    Step  502 : The time domain exchange module sends the first time domain signal to a second baseband processing unit and sends the second time domain signal to a first baseband processing unit. 
         [0063]    Specifically, the time domain exchange module may send the first time domain signal to the second baseband processing unit and send the second time domain signal to the first baseband processing unit according to a predetermined coordination configuration. 
         [0064]    In this embodiment, the predetermined coordination configuration may be configured for the time domain exchange module by a high layer (for example, a base station controller). The predetermined coordination configuration may be a signal sending relationship in which the second time domain signal that is sent by UE  1  through the radio frequency channel of cell  1  is sent to the first baseband processing unit and the first time domain signal that is sent by UE  1  through the radio frequency channel of cell  2  is sent to the second baseband processing unit. 
         [0065]    Step  503 : The second baseband processing unit performs a time-frequency transformation on the first time domain signal to obtain a first frequency domain signal of UE  1  in cell  2 . 
         [0066]    The second baseband processing unit may perform an FFT and a de-mapping processing on the first time domain signal, and obtain a first frequency domain signal of a first user equipment in cell  2  according to high-layer configuration information, where the high-layer configuration information includes a sub-carrier that is configured by a high layer (for example, a base station controller) and is used when UE  1  sends data. 
         [0067]    Step  504 : The first baseband processing unit performs a time-frequency transformation on the second time domain signal to obtain a second frequency domain signal of UE  1  in cell  1 . 
         [0068]    The first baseband processing unit may perform an FFT and a de-mapping processing on the second time domain signal, and obtain a second frequency domain signal of the first user equipment in cell  1  according to high-layer configuration information, where the high-layer configuration information includes a sub-carrier that is configured by a high layer (for example, a base station controller) and is used when UE  1  sends data. 
         [0069]    Steps  505  to  507  are the same as steps  303  to  305 . 
         [0070]    In the present invention, implementation manner of the time domain exchange module is not limited. The time domain exchange module and the at least two baseband processing units may be located in the same baseband board of the base station device; or the time domain exchange module may be formed by at least two time domain exchange chips that are connected to each other, and the at least two time domain exchange chips are located in different baseband boards of the base station device; or the time domain exchange module may be independently disposed in the base station device, for example, the time domain exchange module is not disposed in any baseband board of the base station device. 
         [0071]    In another implementation manner of the embodiment shown in  FIG. 1  of the present invention, the frequency domain exchange module and the at least two baseband processing units are located in the same baseband board of the base station device. As shown in  FIG. 6 ,  FIG. 6  is a schematic diagram of an application scenario according to another embodiment of the present invention. 
         [0072]    In  FIG. 6 , cell  1  and cell  2  are coordinated cells for each other, a serving cell of UE  1  is cell  1  and a coordinated cell of UE  1  is cell  2 .  FIG. 6  is shown by using an example that a base station device includes a frequency domain exchange module and two baseband processing units, where the frequency domain exchange module is connected to each of the two baseband processing units. A first baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to cell  1 ; and a second baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to at least one coordinated cell of UE  1 , that is, a baseband processing unit that corresponds to cell  2 . 
         [0073]    In  FIG. 6 , the frequency domain exchange module, the first baseband processing unit, and the second baseband processing unit are located in the same baseband board of the base station device. 
         [0074]    In the scenario shown in  FIG. 6 , for a CoMP process of UE  1 , reference is made to the description in the embodiment shown in  FIG. 3  of the present invention, and such details are not repeated for conciseness consideration. 
         [0075]    In another implementation manner of the present invention, the frequency domain exchange module includes at least two frequency domain exchange chips that are connected to each other, and the at least two frequency domain exchange chips are located in different baseband boards of the base station device. In this way, the frequency domain exchange module receives a first frequency domain signal of a first user equipment, where the first frequency domain signal is obtained from at least one coordinated cell of the first user equipment and is sent by a baseband processing unit of the at least two baseband processing units, where the baseband processing unit corresponds to the at least one coordinated cell of the first user equipment, which may be: at least one frequency domain exchange chip of the at least two frequency domain exchange chips other than a first frequency domain exchange chip receives a first frequency domain signal of a first user equipment, where the first frequency domain signal is obtained from at least one coordinated cell of the first user equipment and is sent by a baseband processing unit that corresponds to the at least one coordinated cell of the first user equipment, where the first frequency domain exchange chip of the at least two frequency domain exchange chips and the first baseband processing unit are located in the same baseband board. 
         [0076]    In this implementation manner, the frequency domain exchange module sends the first frequency domain signal to the first baseband processing unit of the at least two baseband processing units, where the first baseband processing unit corresponds to a serving cell of the first user equipment, which may be: the first frequency domain exchange chip receives a first frequency domain signal that is sent by the at least one frequency domain exchange chip, and then the first frequency domain exchange chip sends the first frequency domain signal to the first baseband processing unit. 
         [0077]      FIG. 7  is a schematic diagram of an application scenario according to another embodiment of the present invention. In  FIG. 7 , cell  1  and cell  2  are coordinated cells for each other, a serving cell of UE  1  is cell  1 , and a coordinated cell of UE  1  is cell  2 .  FIG. 7  is shown by using an example that a base station device includes a frequency domain exchange module and two baseband processing units. A first baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to cell  1 ; and a second baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to at least one coordinated cell of UE  1 , that is, a baseband processing unit that corresponds to cell  2 . In  FIG. 7 , the frequency domain exchange module is formed by two frequency domain exchange chips that are connected to each other. A first frequency domain exchange chip of the two frequency domain exchange chips is connected to the first baseband processing unit, and the first frequency domain exchange chip and the first baseband processing unit are located in the same baseband board, for example, a first baseband board in  FIG. 7 . A second frequency domain exchange chip of the two frequency domain exchange chips is connected to the second baseband processing unit, and the second frequency domain exchange chip and the first frequency domain exchange chip are located in different baseband boards. The second frequency domain exchange chip and the second baseband processing unit are located in a second baseband board in  FIG. 7 . 
         [0078]      FIG. 8  is a flow chart of a signal sending method according to another embodiment of the present invention, and a CoMP process of UE  1  in  FIG. 7  is described in this embodiment. 
         [0079]    As shown in  FIG. 8 , the signal sending method may include: 
         [0080]    Step  801 : A second baseband processing unit receives a first time domain signal that is sent by UE  1  through a radio frequency channel of cell  2 , and performs a time-frequency transformation on the first time domain signal to obtain a first frequency domain signal of UE  1  in cell  2 . 
         [0081]    The second baseband processing unit may perform an FFT and a de-mapping processing on the first time domain signal, and obtain a first frequency domain signal of a first user equipment in cell  2  according to high-layer configuration information, where the high-layer configuration information includes a sub-carrier that is configured by a high layer (for example, a base station controller) and is used when UE  1  sends data. 
         [0082]    Step  802 : A first baseband processing unit receives a second time domain signal that is sent by UE  1  through a radio frequency channel of cell  1 , and performs a time-frequency transformation on the second time domain signal to obtain a second frequency domain signal of UE  1  in cell  1 . 
         [0083]    The first baseband processing unit may perform an FFT and a de-mapping processing on the second time domain signal, and obtain a second frequency domain signal of the first user equipment in cell  1  according to high-layer configuration information, where the high-layer configuration information includes a sub-carrier that is configured by a high layer (for example, a base station controller) and is used when UE  1  sends data. 
         [0084]    Step  803 : The second baseband processing unit sends the first frequency domain signal to a second frequency domain exchange chip. 
         [0085]    Step  804 : The second frequency domain exchange chip sends the first frequency domain signal to a first frequency domain exchange chip. 
         [0086]    Specifically, after receiving the first frequency domain signal, the second frequency domain exchange chip finds that the first frequency domain signal is a frequency domain signal of 
         [0087]    UE  1  in cell  2 , while a serving cell of UE 1  is cell  1 , a baseband processing unit that corresponds to cell  1  is the first baseband processing unit, and the first baseband processing unit is located in a first baseband board. Therefore, the second frequency domain exchange chip may send, according to a CoMP coordination relationship that is configured by a high layer (for example, a base station controller), the first frequency domain signal to the first frequency domain exchange chip that is located in the first baseband board. 
         [0088]    The CoMP coordination relationship that is configured by the high layer may be a signal sending relationship in which the frequency domain signal of UE  1  in cell  2  is sent to a frequency domain exchange chip in a baseband board where the baseband processing unit that corresponds to cell  1  is located. 
         [0089]    Step  805 : The first frequency domain exchange chip sends the first frequency domain signal to the first baseband processing unit. 
         [0090]    Step  806 : The first baseband processing unit performs a joint processing on the first frequency domain signal and the second frequency domain signal. 
         [0091]    For example, the first baseband processing unit may first perform a MIMO decoding and an equalization processing on the first frequency domain signal and the second frequency domain signal, and then perform a processing such as IDFT/demodulation/de-interleaving/HARQ combination/decoding/CRC. 
         [0092]    In another implementation manner of the embodiment shown in  FIG. 1  of the present invention, the first baseband processing unit is located in a first baseband board in a base station device; a baseband processing unit of the at least two baseband processing units, which corresponds to at least one coordinated cell of a first user equipment, is located in a baseband board other than the first baseband board in the base station device; and the frequency domain exchange module is independently disposed in the base station device, that is to say, the frequency domain exchange module is not disposed in any baseband board of the base station device. 
         [0093]      FIG. 9  is a schematic diagram of an application scenario according to another embodiment of the present invention. In  FIG. 9 , cell  1  and cell  2  are coordinated cells for each other, a serving cell of UE  1  is cell  1 , and a coordinated cell of UE  1  is cell  2 .  FIG. 9  is shown by using an example that a base station device includes a frequency domain exchange module and two baseband processing units. A first baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to cell  1 ; and a second baseband processing unit of the two baseband processing units is a baseband processing unit that corresponds to at least one coordinated cell of UE  1 , that is, a baseband processing unit that corresponds to cell  2 . 
         [0094]    In  FIG. 9 , the first baseband processing unit is located in a first baseband board in the base station device, and the second baseband processing unit is located in a second baseband board in the base station device. The frequency domain exchange module is independently disposed in the base station device, that is, the frequency domain exchange module is not located in any baseband board of the base station device. 
         [0095]    In the scenario shown in  FIG. 9 , for a CoMP process of UE  1 , reference is made to the description in the embodiment shown in  FIG. 3  of the present invention, and such details are not repeated for conciseness consideration. 
         [0096]      FIG. 10  is a flow chart of a signal sending method according to another embodiment of the present invention. The signal sending method provided in this embodiment may be applied in a base station device that includes a time-frequency transformation module and at least one baseband processing unit, and the time-frequency transformation module is connected to the at least one baseband processing unit. 
         [0097]    As shown in  FIG. 10 , the signal sending method may include: 
         [0098]    Step  1001 : The time-frequency transformation module receives a first time domain signal that is sent by a first user equipment through a radio frequency channel of a serving cell of the first user equipment, and receives a second time domain signal that is sent by the first user equipment through a radio frequency channel of at least one coordinated cell of the first user equipment. 
         [0099]    Step  1002 : The time-frequency transformation module performs a time-frequency transformation on the first time domain signal and the second time domain signal, to obtain frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment. 
         [0100]    Step  1003 : The time-frequency transformation module sends the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment to a first baseband processing unit of the at least one baseband processing unit, where the first baseband processing unit corresponds to the serving cell of the first user equipment. 
         [0101]    In an implementation manner of this embodiment, the time-frequency transformation module may first send the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment to a frequency domain exchange module that is connected to the time-frequency transformation module, and then the frequency domain exchange module sends the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment to the first baseband processing unit. The time-frequency transformation module, the frequency domain exchange module, and the at least one baseband processing unit are located in the same baseband board of the base station device; or the first baseband processing unit is located in a first baseband board in the base station device, and the time-frequency transformation module and the frequency domain exchange module are independently disposed in the base station device, that is, the time-frequency transformation module and the frequency domain exchange module are not disposed in any baseband board in the base station device. 
         [0102]    In the foregoing embodiment, after receiving the first time domain signal that is sent by the first user equipment through the radio frequency channel of the serving cell of the first user equipment and the second time domain signal that is sent by the first user equipment through the radio frequency channel of the at least one coordinated cell of the first user equipment, the time-frequency transformation module performs a time-frequency transformation on the first time domain signal and the second time domain signal, to obtain the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment. Afterwards, the time-frequency transformation module sends the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment to the first baseband processing unit of the at least one baseband processing unit, where the first baseband processing unit corresponds to the serving cell of the first user equipment. In this way, data exchange between a serving cell and a coordinated cell in an LTE-A system can be implemented, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0103]    In an implementation manner of the embodiment shown in  FIG. 10  of the present invention, the time-frequency transformation module and the at least one baseband processing unit are located in the same baseband board of the base station device. As shown in  FIG. 11 ,  FIG. 11  is a schematic diagram of an application scenario according to another embodiment of the present invention. 
         [0104]    In  FIG. 11 , cell  1  and cell  2  are coordinated cells for each other, a serving cell of UE  1  is cell  1  and a coordinated cell of UE  1  is cell  2 .  FIG. 11  is shown by using an example that a base station device includes a time-frequency transformation module and one baseband processing unit, and the one baseband processing unit is a first baseband processing unit that corresponds to a serving cell of a first user equipment. In  FIG. 11 , the first baseband processing unit and the time-frequency transformation module are located in a first baseband board in the base station device. In addition, in  FIG. 11 , a first frequency domain signal is a frequency domain signal of the first user equipment in cell  2 , and a second frequency domain signal is a frequency domain signal of the first user equipment in cell  1 . 
         [0105]    In the scenario shown in  FIG. 11 , for a CoMP process of UE  1 , reference is made to the description in the embodiment shown in  FIG. 10  of the present invention, and such details are not repeated for conciseness consideration. 
         [0106]    In the scenario shown in  FIG. 11 , through a frequency domain exchange module, a frequency domain signal in the first baseband board may also be sent in the first baseband board. That is to say, the time-frequency transformation module may first send the first frequency domain signal and the second frequency domain signal to the frequency domain exchange module that is connected to the time-frequency transformation module, and then the frequency domain exchange module sends the first frequency domain signal and the second frequency domain signal to the first baseband processing unit that is connected to the frequency domain exchange module. The time-frequency transformation module, the frequency domain exchange module, and the first baseband processing unit are located in the same baseband board (for example, the first baseband board in  FIG. 11 ) of the base station device. 
         [0107]    In another implementation manner of the embodiment shown in  FIG. 10  of the present invention, the first baseband processing unit is located in the first baseband board in the base station device, and the time-frequency transformation module is independently disposed in the base station device, that is to say, the time-frequency transformation module is not disposed in any baseband board of the base station device. As shown in  FIG. 12 ,  FIG. 12  is a schematic diagram of an application scenario according to another embodiment of the present invention. 
         [0108]    In  FIG. 12 , cell  1  and cell  2  are coordinated cells for each other, a serving cell of UE  1  is cell  1  and a coordinated cell of UE  1  is cell  2 .  FIG. 12  is shown by using an example that a base station device includes a time-frequency transformation module and one baseband processing unit, and the one baseband processing unit is a first baseband processing unit that corresponds to a serving cell of a first user equipment. In  FIG. 12 , the first baseband processing unit is located in a first baseband board in the base station device, and the time-frequency transformation module is independently disposed in the base station device, that is, the time-frequency transformation module is not disposed in any baseband board of the base station device. In addition, in  FIG. 12 , a first frequency domain signal is a frequency domain signal of the first user equipment in cell  2 , and a second frequency domain signal is a frequency domain signal of the first user equipment in cell  1 . 
         [0109]    In the scenario shown in  FIG. 12 , for a CoMP process of UE  1 , reference is made to the description in the embodiment shown in  FIG. 10  of the present invention, and such details are not repeated for conciseness consideration. 
         [0110]    In the scenario shown in  FIG. 12 , the first frequency domain signal and the second frequency domain signal may also be sent to the first baseband processing unit through a frequency domain exchange module. That is to say, the time-frequency transformation module may first send the first frequency domain signal and the second frequency domain signal to the frequency domain exchange module that is connected to the time-frequency transformation module, and then the frequency domain exchange module sends the first frequency domain signal and the second frequency domain signal to the first baseband processing unit that is connected to the frequency domain exchange module. The first baseband processing unit is located in the first baseband board of the base station device, and the time-frequency transformation module and the frequency domain exchange module are independently disposed in the base station device, that is, the time-frequency transformation module and the frequency domain exchange module are not disposed in any baseband board in the base station device. 
         [0111]    Persons of ordinary skill in the art may understand that all or part of the steps of the method embodiments may be implemented by a program instructing relevant hardware. The program may be stored in a computer readable storage medium. When the program runs, the steps of the method embodiments are performed. The storage medium may be any medium capable of storing program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk. 
         [0112]      FIG. 13  is a schematic structural diagram of a base station device according to an embodiment of the present invention. In this embodiment, the base station device may implement a procedure in the embodiment shown in  FIG. 1  of the present invention. As shown in  FIG. 13 , the base station device may include a frequency domain exchange module  1301  and at least two baseband processing units  1302 , where the frequency domain exchange module  1301  is connected to each of the at least two baseband processing units  1302 . 
         [0113]    A baseband processing unit of the at least two baseband processing units  1302 , which corresponds to at least one coordinated cell of a first user equipment, is configured to send a first frequency domain signal of the first user equipment to the frequency domain exchange module  1301 , where the first frequency domain signal is obtained from the at least one coordinated cell of the first user equipment. 
         [0114]    The frequency domain exchange module  1301  is configured to receive the first frequency domain signal, and send the first frequency domain signal to a first baseband processing unit of the at least two baseband processing units  1302 , where the first baseband processing unit corresponds to a serving cell of the first user equipment. 
         [0115]    The first baseband processing unit is configured to perform a joint processing on the first frequency domain signal and a second frequency domain signal of the first user equipment, where the second frequency domain signal is obtained from the serving cell of the first user equipment by the first baseband processing unit. For example, the first baseband processing unit may first perform a MIMO decoding and an equalization processing on the first frequency domain signal and the second frequency domain signal, and then perform a processing such as IDFT/demodulation/de-interleaving/HARQ combination/decoding/CRC. 
         [0116]    Further, the baseband processing unit of the at least two baseband processing units  1302 , which corresponds to the at least one coordinated cell of the first user equipment, is further configured to receive a first time domain signal that is sent by the first user equipment through a radio frequency channel of the at least one coordinated cell of the first user equipment, and perform a time-frequency transformation on the first time domain signal to obtain the first frequency domain signal. 
         [0117]    Further, the first baseband processing unit is further configured to receive a second time domain signal that is sent by the first user equipment through a radio frequency channel of the serving cell of the first user equipment, and perform a time-frequency transformation on the second time domain signal to obtain the second frequency domain signal. 
         [0118]    In this embodiment, the baseband processing unit may be a layer  1  (L 1 ) processing chip. 
         [0119]      FIG. 13  is shown by using an example that a base station device includes a frequency domain exchange module  1301  and two baseband processing units  1302 , where the frequency domain exchange module  1301  is connected to each of the two baseband processing units  1302 . A first baseband processing unit  1302   a  of the two baseband processing units  1302  is a baseband processing unit that corresponds to a serving cell of a first user equipment. A second baseband processing unit  1302   b  of the two baseband processing units  1302  is a baseband processing unit that corresponds to at least one coordinated cell of the first user equipment. 
         [0120]    In the foregoing embodiment, after the frequency domain exchange module  1301  receives a first frequency domain signal of a first user equipment, where the first frequency domain signal is obtained from at least one coordinated cell of the first user equipment and is sent by a baseband processing unit of the at least two baseband processing units  1302  that is connected to the frequency domain exchange module  1301 , where the baseband processing unit corresponds to the at least one coordinated cell of the first user equipment, the frequency domain exchange module  1301  sends the first frequency domain signal to the first baseband processing unit  1302   a  of the at least two baseband processing units  1302 , where the first baseband processing unit  1302   a  corresponds to a serving cell of the first user equipment, so that the first baseband processing unit  1302   a  performs a joint processing on the first frequency domain signal and a second frequency domain signal of the first user equipment, where the second frequency domain signal is obtained from the serving cell of the first user equipment by the first baseband processing unit. In this way, data exchange between a serving cell and a coordinated cell in an LTE-A system can be implemented, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0121]      FIG. 14  is a schematic structural diagram of a base station device according to another embodiment of the present invention. The base station device in this embodiment may implement a procedure of the embodiment shown in  FIG. 5  of the present invention. Compared with the base station device shown in  FIG. 13 , a difference lies in that, the base station device shown in  FIG. 14  may further include: a time domain exchange module  1303 , where the time domain exchange module  1303  is connected to each of at least two baseband processing units  1302 . 
         [0122]    The time domain exchange module  1303  is configured to receive a first time domain signal that is sent by a first user equipment through a radio frequency channel of at least one coordinated cell of the first user equipment, and send the first time domain signal to a baseband processing unit that corresponds to the at least one coordinated cell of the first user equipment. 
         [0123]    The time domain exchange module  1303  is further configured to receive a second time domain signal that is sent by the first user equipment through a radio frequency channel of a serving cell of the first user equipment, and send the second time domain signal to a first baseband processing unit  1302   a.    
         [0124]      FIG. 14  is shown by using an example that a base station device includes a frequency domain exchange module  1301 , two baseband processing units  1302 , and a time domain exchange module  1303 , where the frequency domain exchange module  1301  is connected to each of the two baseband processing units  1302 , and the time domain exchange module  1303  is also connected to each of the two baseband processing units  1302 . A first baseband processing unit  1302   a  of the two baseband processing units  1302  is a baseband processing unit that corresponds to a serving cell of a first user equipment. A second baseband processing unit  1302   b  of the two baseband processing units  1302  is a baseband processing unit that corresponds to at least one coordinated cell of the first user equipment. 
         [0125]    In this embodiment, implementation manner of the time domain exchange module  1303  is not limited. The time domain exchange module  1303  and the at least two baseband processing units  1302  may be located in the same baseband board of the base station device; or the time domain exchange module  1303  may be formed by at least two time domain exchange chips that are connected to each other, and the at least two time domain exchange chips are located in different baseband boards of the base station device; or the time domain exchange module  1303  may be independently disposed in the base station device, for example, the time domain exchange module  1303  is not disposed in any baseband board of the base station device. 
         [0126]    The base station device may implement data exchange between a serving cell and a coordinated cell in an LTE-A system, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0127]      FIG. 15  is a schematic structural diagram of a base station device according to another embodiment of the present invention. Compared with the base station device shown in  FIG. 13 , a difference lies in that, in the base station device shown in  FIG. 15 , a frequency domain exchange module  1301  and at least two baseband processing units  1302  are located in the same baseband board of the base station device. 
         [0128]      FIG. 15  is shown by using an example that a base station device includes a frequency domain exchange module  1301  and two baseband processing units  1302 , where the frequency domain exchange module  1301  is connected to each of the two baseband processing units  1302 . A first baseband processing unit  1302   a  of the two baseband processing units  1302  is a baseband processing unit that corresponds to a serving cell of a first user equipment. A second baseband processing unit  1302   b  of the two baseband processing units  1302  is a baseband processing unit that corresponds to at least one coordinated cell of the first user equipment. As shown in  FIG. 15 , the frequency domain exchange module  1301 , the first baseband processing unit  1302   a,  and the second baseband processing unit  1302   b  are located in a first baseband board  1304  of the base station device. 
         [0129]    The base station device may implement data exchange between a serving cell and a coordinated cell in an LTE-A system, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0130]      FIG. 16  is a schematic structural diagram of a base station device according to another embodiment of the present invention. The base station device in this embodiment may implement a procedure of the embodiment shown in  FIG. 8  of the present invention. Compared with the base station device shown in  FIG. 13 , a difference lies in that, in the base station device shown in  FIG. 16 , a frequency domain exchange module  1301  may include at least two frequency domain exchange chips that are connected to each other. The at least two frequency domain exchange chips are located in different baseband boards in the base station device, and a first frequency domain exchange chip of the at least two frequency domain exchange chips and a first baseband processing unit are located in the same baseband board. 
         [0131]    At least one frequency domain exchange chip of the at least two frequency domain exchange chips other than the first frequency domain exchange chip is configured to receive a first frequency domain signal of a first user equipment, where the first frequency domain signal is obtained from at least one coordinated cell of the first user equipment and is sent by a baseband processing unit that corresponds to the at least one coordinated cell of the first user equipment. 
         [0132]    The first frequency domain exchange chip is configured to receive the first frequency domain signal sent by the at least one frequency domain exchange chip, and send the first frequency domain signal to the first baseband processing unit. 
         [0133]      FIG. 16  is shown by using an example that a base station device includes a frequency domain exchange module  1301  and two baseband processing units  1302 , where the frequency domain exchange module  1301  is connected to each of the two baseband processing units  1302 . A first baseband processing unit  1302   a  of the two baseband processing units  1302  is a baseband processing unit that corresponds to a serving cell of a first user equipment. A second baseband processing unit  1302   b  of the two baseband processing units  1302  is a baseband processing unit that corresponds to at least one coordinated cell of the first user equipment. Moreover,  FIG. 16  is shown by using an example that the frequency domain exchange module  1301  includes two frequency domain exchange chips that are connected to each other. In  FIG. 16 , the two frequency domain exchange chips are a first frequency domain exchange chip  13011  and a second frequency domain exchange chip  13012  respectively. 
         [0134]    The first frequency domain exchange chip  13011  and the first baseband processing unit  1302   a  are located in a first baseband board  1304  of the base station device, and the second frequency domain exchange chip  13012  and the second baseband processing unit  1302   b  are located in a second baseband board  1305  of the base station device. 
         [0135]    The base station device may implement data exchange between a serving cell and a coordinated cell in an LTE-A system, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0136]      FIG. 17  is a schematic structural diagram of a base station device according to another embodiment of the present invention. Compared with the base station device shown in  FIG. 13 , a difference lies in that, in the base station device shown in  FIG. 17 , a first baseband processing unit is located in a first baseband board of the base station device, a baseband processing unit of at least two baseband processing units  1302 , which corresponds to at least one coordinated cell of a first user equipment is located in a baseband board other than the first baseband board in the base station device, and a frequency domain exchange module  1301  is independently disposed in the base station device. 
         [0137]      FIG. 17  is shown by using an example that a base station device includes a frequency domain exchange module  1301  and two baseband processing units  1302 , where the frequency domain exchange module  1301  is connected to each of the two baseband processing units  1302 . A first baseband processing unit  1302   a  of the two baseband processing units  1302  is a baseband processing unit that corresponds to a serving cell of a first user equipment. A second baseband processing unit  1302   b  of the two baseband processing units  1302  is a baseband processing unit that corresponds to at least one coordinated cell of the first user equipment. 
         [0138]    As shown in  FIG. 17 , the first baseband processing unit  1302   a  is located in the first baseband board  1304  in the base station device, the second baseband processing unit  1302   b  is located in the second baseband board  1305  in the base station device, and the frequency domain exchange module  1301  is independently disposed in the base station device, that is to say, the frequency domain exchange module  1301  is not disposed in any baseband board of the base station device. 
         [0139]    The base station device may implement data exchange between a serving cell and a coordinated cell in an LTE-A system, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0140]      FIG. 18  is a schematic structural diagram of a base station device according to another embodiment of the present invention. The base station device in this embodiment may implement a procedure of the embodiment shown in  FIG. 10  of the present invention. As shown in  FIG. 18 , the base station device may include: a time-frequency transformation module  1801  and at least one baseband processing unit  1802 , where the time-frequency transformation module  1801  is connected to the at least one baseband processing unit  1802 . 
         [0141]    The time-frequency transformation module  1801  is configured to receive a first time domain signal that is sent by a first user equipment through a radio frequency channel of a serving cell of the first user equipment, receive a second time domain signal that is sent by the first user equipment through a radio frequency channel of at least one coordinated cell of the first user equipment, perform a time-frequency transformation on the first time domain signal and the second time domain signal to obtain frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment, and send the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment to a first baseband processing unit of the at least one baseband processing unit  1802 , where the first baseband processing unit corresponds to the serving cell of the first user equipment. 
         [0142]    The first baseband processing unit is configured to receive the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment, where the frequency domain signals are sent by the time-frequency transformation module  1801 , and perform a joint processing on the frequency domain signals. For example, the first baseband processing unit may first perform a MIMO decoding and an equalization processing on the frequency domain signals, and then perform a processing such as IDFT/demodulation/de-interleaving/HARQ combination/decoding/CRC. 
         [0143]      FIG. 18  is described by using an example that a base station device includes a time-frequency transformation module  1801  and one baseband processing unit  1802 . The time-frequency transformation module  1801  is connected to the one baseband processing unit  1802 , and the one baseband processing unit  1802  is a first baseband processing unit  1802  that corresponds to a serving cell of a first user equipment. 
         [0144]    In the foregoing embodiment, the time-frequency transformation module  1801  receives a first time domain signal that is sent by a first user equipment through a radio frequency channel of a serving cell of the first user equipment, receives a second time domain signal that is sent by the first user equipment through a radio frequency channel of at least one coordinated cell of the first user equipment, and then performs time-frequency transformation on the first time domain signal and the second time domain signal to obtain frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment; and afterwards, the time-frequency transformation module  1801  sends the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment to a first baseband processing unit of the at least one baseband processing unit  1802 , where the first baseband processing unit corresponds to the serving cell of the first user equipment. In this way, data exchange between a serving cell and a coordinated cell in an LTE-A system can be implemented, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0145]      FIG. 19  is a schematic structural diagram of a base station device according to another embodiment of the present invention. Compared with the base station device shown in  FIG. 18 , a difference lies in that, the base station device shown in  FIG. 19  may further include a frequency domain exchange module  1803 , where the frequency domain exchange module  1803  is connected to a time-frequency transformation module  1801 . 
         [0146]    The time-frequency transformation module  1801  is specifically configured to send frequency domain signals of a first user equipment in a serving cell and in at least one coordinated cell of the first user equipment to the frequency domain exchange module  1803 . 
         [0147]    The frequency domain exchange module  1803  is connected to a first baseband processing unit  1802  and is configured to send the frequency domain signals of the first user equipment in the serving cell and in the at least one coordinated cell of the first user equipment to the first baseband processing unit  1802 . 
         [0148]      FIG. 19  is described by using an example that a base station device includes a time-frequency transformation module  1801 , one baseband processing unit  1802 , and a frequency domain exchange module  1803 . The time-frequency transformation module  1801  is connected to the one baseband processing unit  1802 , and the frequency domain exchange module  1803  is also connected to the one baseband processing unit  1802 . The one baseband processing unit  1802  is a first baseband processing unit  1802  that corresponds to a serving cell of a first user equipment. 
         [0149]    The base station device may implement data exchange between a serving cell and a coordinated cell in an LTE-A system, thereby effectively reducing influence of interference and improving the quality of a radio signal. 
         [0150]      FIG. 20  is a schematic structural diagram of a base station device according to another embodiment of the present invention. Compared with the base station device shown in  FIG. 18 , a difference lies in that, in the base station device shown in  FIG. 20 , a time-frequency transformation module  1801  and at least one baseband processing unit  1802  are located in the same baseband board of the base station device. 
         [0151]      FIG. 20  is described by using an example that a base station device includes a time-frequency transformation module  1801  and one baseband processing unit  1802 . The time-frequency transformation module  1801  is connected to the one baseband processing unit  1802 , and the one baseband processing unit  1802  is a first baseband processing unit  1802  that corresponds to a serving cell of a first user equipment. 
         [0152]    As shown in  FIG. 20 , the time-frequency transformation module  1801  and the first baseband processing unit  1802  are located in a first baseband board  1804  of the base station device. 
         [0153]      FIG. 21  is a schematic structural diagram of a base station device according to another embodiment of the present invention. Compared with the base station device shown in  FIG. 19 , a difference lies in that, in the base station device shown in  FIG. 21 , a time-frequency transformation module  1801 , a frequency domain exchange module  1803 , and at least one baseband processing unit  1802  are located in the same baseband board of the base station device. 
         [0154]      FIG. 21  is described by using an example that a base station device includes a time-frequency transformation module  1801 , one baseband processing unit  1802 , and a frequency domain exchange module  1803 . The time-frequency transformation module  1801  is connected to the one baseband processing unit  1802 , and the frequency domain exchange module  1803  is also connected to the one baseband processing unit  1802 . The one baseband processing unit  1802  is a first baseband processing unit  1802  that corresponds to a serving cell of a first user equipment. 
         [0155]    As shown in  FIG. 21 , the time-frequency transformation module  1801 , the first baseband processing unit  1802 , and the frequency domain exchange module  1803  are located in a first baseband board  1804  of the base station device. 
         [0156]      FIG. 22  is a schematic structural diagram of a base station device according to another embodiment of the present invention. Compared with the base station device shown in  FIG. 18 , a difference lies in that, in the base station device shown in  FIG. 22 , a first baseband processing unit  1802  is located in a first baseband board  1804  in the base station device and a time-frequency transformation module  1801  is independently disposed in the base station device, that is to say, the time-frequency transformation module  1801  is not disposed in any baseband board of the base station device. 
         [0157]      FIG. 22  is described by using an example that a base station device includes a time-frequency transformation module  1801  and one baseband processing unit  1802 . The time-frequency transformation module  1801  is connected to the one baseband processing unit  1802 , and the one baseband processing unit  1802  is a first baseband processing unit  1802  that corresponds to a serving cell of a first user equipment. 
         [0158]    As shown in  FIG. 22 , the first baseband processing unit  1802  is located in the first baseband board  1804  of the base station device. The time-frequency transformation module  1801  is independently disposed in the base station device, that is to say, the time-frequency transformation module  1801  is not disposed in any baseband board of the base station device. 
         [0159]      FIG. 23  is a schematic structural diagram of a base station device according to another embodiment of the present invention. Compared with the base station device shown in  FIG. 19 , a difference lies in that, in the base station device shown in  FIG. 23 , a first baseband processing unit  1802  is located in a first baseband board  1804  in the base station device, and a time-frequency transformation module  1801  and a frequency domain exchange module  1803  are independently disposed in the base station device, that is to say, the time-frequency transformation module  1801  and the frequency domain exchange module  1803  are not disposed in any baseband board of the base station device. 
         [0160]      FIG. 23  is described by using an example that a base station device includes a time-frequency transformation module  1801 , one baseband processing unit  1802 , and a frequency domain exchange module  1803 . The time-frequency transformation module  1801  is connected to the one baseband processing unit  1802 , and the frequency domain exchange module  1803  is also connected to the one baseband processing unit  1802 . The one baseband processing unit  1802  is a first baseband processing unit  1802  that corresponds to a serving cell of a first user equipment. 
         [0161]    As shown in  FIG. 23 , the first baseband processing unit  1802  is located in the first baseband board  1804  of the base station device. The time-frequency transformation module  1801  and the frequency domain exchange module  1803  are independently disposed in the base station device, that is to say, the time-frequency transformation module  1801  and the frequency domain exchange module  1803  are not disposed in any baseband board of the base station device. 
         [0162]    It should be understood by persons skilled in the art that the accompanying drawings are merely schematic diagrams of one exemplary embodiment, and modules or procedures in the accompanying drawings are not necessarily required in implementing the present invention. 
         [0163]    Persons skilled in the art may understand that the modules in the devices provided in the embodiments may be arranged in the devices in a distributed manner according to the description of the embodiments, or may be arranged in one or multiple devices which are different from those described in the embodiments. The modules in the foregoing embodiments may be combined into one module, and may also be split into multiple submodules. 
         [0164]    Finally, it should be noted that the foregoing embodiments are merely provided for describing the technical solutions of the present invention, but are not intended to limit the present invention. It should be understood by persons of ordinary skill in the art that although the present invention has been described in detail with reference to the foregoing embodiments, modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent replacements can be made to some or all technical features in the technical solutions, as long as such modifications or replacements do not cause the essence of corresponding technical solutions to depart from the scope of the technical solutions in the embodiments of the present invention.