Abstract:
An antenna multiplexing system and a method of a smart antenna and a Multiple-Input Multiple-Output antenna are provided, wherein the system includes a MIMO antenna array and a smart antenna array, the smart antenna array includes several groups of antenna array elements in which the distance between neighbor antenna array elements is less than or equal to one half of wavelength, and the smart antenna array comprises at least two groups of antenna array elements with the coherence sufficient for the requirement of the MIMO applications. The method includes: in accordance with the type of the data to be transmitted, determining a transmitting mode and processing the data to be transmitted accordingly, and in accordance with the transmitting mode, controlling the MIMO antenna array or smart antenna array, so as to transmitting the data to the mobile terminal. With the premise that the actual coverage of TD-SCDMA system should be further improved, the requirement of higher user throughout could be met, and the MIMO antenna system could satisfy the requirement of the future system evolution. Both of the applications of the MIMO and the smart antenna could be met with the use of the same antenna feeding system, and the adaptive switching of the MIMO and the smart antenna with respect to the user could be achieved.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a multiple antenna system and method, particularly to an antenna multiplexing system and method of a smart antenna and a Multiple-Input Multiple-Output antenna. 
     BACKGROUND OF THE INVENTION 
     The current multiple antenna technique mainly includes two forms: a smart antenna system, and a Multiple-Input Multiple-Output (MIMO) antenna system. In the MIMO antenna system, multiple antennas are used to suppress channel fading or to improve channel capacity, which may provide spatial multiplexing gain and spatial diversity gain for the system, wherein spatial multiplexing technology may greatly improve the channel capacity and spatial diversity may increase reliability of a channel and decrease bit error rate of the channel. The MIMO antenna system mainly achieves diversity gain dependent upon independence of spatial channel fading characteristics on different antenna pairs. Therefore, larger antenna element spacing is needed in the MIMO antenna system. 
     The smart antenna system mainly performs signal processing dependent upon high dependence between array elements to achieve beam forming. Therefore, smaller antenna element spacing is needed in the smart antenna system, which is set to ½ wavelength while applied currently in a Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system in a third generation mobile communication system. For example, in the TD-SCDMA system, all elements of a smart antenna array (assume a number of the elements is N, where N is a positive integer) employ the same vertical polarization. Each antenna element spacing is ½ wavelength. The N antenna elements act together on beams from respective directions to perform spatial filter. Narrow beams with high gain is point to the direction of a served user, and null is pointed to the direction of interference, which increase output signal-to-jamming ratio of the array and reduce the interference inside the system while improving the anti-interference capability and the coverage capability of the system. However, since a common channel and a broadcast channel (or a MBMS service) do not have a downlink beam forming gain, there is a significant difference between the coverage capability of the common channel and the broadcast channel (or the MBMS service) and that of a channel for a general service, so that the actual coverage range of the network or the MBMS service is smaller than that of a service channel, which results in that advantages of the performance of the smart antenna may not be presented sufficiently. Although interference of the common channel in a multi-frequency cellular network may be reduced to some extent by the multi-frequency networking technique, the actual network indicates that the coverage capability of the common channel is still weaker than that of the service channel. 
     SUMMARY OF THE INVENTION 
     An object of an embodiment of the present invention is to provide an antenna multiplexing system and method of a smart antenna and a Multiple-Input Multiple-Output antenna, which, by the organic combination of the smart antenna and the Multiple-Input Multiple-Output antenna, achieves common presence and common use of the smart antenna and the MIMO antenna in a system. The unbalance between the coverage capability of the common channel and that of the service channel in the TD-SCDMA system is rectified by the MIMO technique and the requirement of higher throughput in a evolution system in the future may be met. The requirement of application of the MIMO antenna and the smart antenna may be met by the same antenna-feeder system, and adaptive switching for a user between the MIMO antenna and the smart antenna may be achieved. 
     To achieve the above object, an embodiment of the present invention provides an antenna multiplexing system of a smart antenna and a Multiple-Input Multiple-Output antenna, including an MIMO antenna array and a smart antenna array, the smart antenna array includes a number of antenna elements, spacing of adjacent antenna elements being smaller than or equal to ½ wavelength, and the MIMO antenna array consists of at least two antenna elements with dependence satisfying requirements of MIMO application. 
     The antenna multiplexing system of the smart antenna and the Multiple-Input Multiple-Output antenna further includes a transmitting processing device configured for controlling the MIMO antenna array and the smart antenna array to transmit a data to a mobile terminal. 
     The transmitting processing device includes: 
     a determining module configured for determining a transmitting mode according to a type of a data to be transmitted, correspondingly processing the data to be transmitted under the transmitting mode, and controlling transmission of the data; 
     an MIMO antenna array transmitting processing module configured for transmitting a control information data or an MBMS service data to all mobile terminals in a cell through the MIMO antenna array according to the transmitting mode, to meet the requirement of balance of coverage capability of a TD-SCDMA system; and 
     a smart antenna array transmitting processing module configured for transmitting a general service data to a single target mobile terminal in the cell through the smart antenna array according to the transmitting mode, to reduce interference between users and enhance the coverage capability. 
     The determining module includes: 
     a transmitting mode determining unit configured for determining the transmitting mode according to the type of the data to be transmitted; 
     a data channel code, scrambling code and intermediate code assigning unit configured for selecting and assigning a corresponding channel code, scrambling code and intermediate code to the data to be transmitted of different types according to the transmitting mode; 
     a data spread spectrum processing unit configured for performing spread spectrum processing on the data to be transmitted according to the channel code and scrambling code; 
     a multiplexing unit configured for multiplexing the data to be transmitted after spread spectrum processing and the corresponding intermediate code to constitute a burst; 
     an ON/OFF controller provided on a transmitting path of the multiplexing unit; and 
     a transmitting mode control unit configured for transmitting the burst through the MIMO antenna array transmitting processing module or the smart antenna array transmitting processing module by controlling the ON/OFF controller according to the transmitting mode determined by the transmitting mode determining unit. 
     The transmitting mode respectively is to transmit a data to all mobile terminals in the cell by the MIMO antenna array and to transmit a data to a single target mobile terminal in the cell by the smart antenna array. 
     On the basis of the technical solution of the antenna multiplexing system, the MIMO antenna array and the smart antenna array constitute an antenna array with N antenna elements, wherein N is an integer, M antenna elements in the antenna array with dependence satisfying the requirement of MIMO application constituting the MIMO antenna array, wherein M is an integer no smaller than 2, and the remaining N-M antenna elements with spacing smaller than or equal to ½ wavelength constituting the smart antenna array. 
     On the basis of the technical solution of the antenna multiplexing system, the MIMO antenna array and the smart antenna array may both be vertically polarized antenna arrays. It is also possible that the MIMO antenna array is a dual-polarized antenna, and the smart antenna array is a vertically polarized antenna. 
     Preferably, the antenna array with N antenna elements is a linear antenna array, and the N-M antenna elements constitute a directional smart antenna array. 
     Preferably, the M antenna elements constituting the MIMO antenna array are located at an end portion of the linear antenna array. 
     Preferably, the antenna array with N antenna elements is a combined antenna array, and the N-M antenna elements constitute a directional smart antenna array in a linear layout or an omnidirectional smart antenna array in a circular layout. 
     On the basis of the technical solution of the antenna multiplexing system, the MIMO antenna array and the smart antenna array constitute an antenna array with N antenna elements, wherein N is an integer, M antenna elements in the antenna array with dependence satisfying the requirement of MIMO application constituting the MIMO antenna array, wherein M is an integer no smaller than 2, and all the N antenna elements with spacing of adjacent antenna elements smaller than or equal to ½ wavelength constituting the smart antenna array. 
     On the basis of the technical solution of the antenna multiplexing system, the MIMO antenna array and the smart antenna array may both be vertically polarized antenna arrays. It is also possible that the MIMO antenna array is a dual-polarized antenna, and the smart antenna array is a vertically polarized antenna. 
     Preferably, the antenna array with N antenna elements is a linear antenna array, and all the N antenna elements constitute a directional smart antenna array. 
     Preferably, the M antenna elements constituting the MIMO antenna array are located at an end portion of the linear antenna array. 
     Preferably, the antenna array with N antenna elements is a circular antenna array, and all the N antenna elements constitute an omnidirectional smart antenna array. 
     To achieve the above object, an embodiment of the present invention provides an antenna multiplexing method of a smart antenna and a Multiple-Input Multiple-Output antenna, including: 
     determining a transmitting mode according to a type of a data to be transmitted and correspondingly processing the data to be transmitted under the transmitting mode; and 
     controlling the MIMO antenna array to transmit a control information or an MBMS service data to all mobile terminals in a cell according to the transmitting mode, or controlling 
     the smart antenna array to transmit a general service data to a single target mobile terminal in the cell according to the transmitting mode, the smart antenna array include a number of antenna elements, spacing of adjacent antenna elements being smaller than or equal to ½ wavelength, and the MIMO antenna array consists of at least two antenna elements with dependence satisfying requirement of MIMO application. 
     The determining the transmitting mode according to the type of the data to be transmitted and correspondingly processing the data to be transmitted under the transmitting mode including: 
     determining the transmitting mode according to the type of the data to be transmitted; 
     selecting and assigning a corresponding channel code, scrambling code and intermediate code to the data to be transmitted of different types according to the transmitting mode; 
     performing spread spectrum processing on the data to be transmitted according to the determined channel code and scrambling code; and 
     multiplexing the data to be transmitted after spread spectrum processing and the corresponding intermediate code to constitute a burst. 
     The transmitting mode respectively is to transmit a data to all mobile terminals in the cell by the MIMO antenna array and to transmit a data to a single target mobile terminal in the cell by the smart antenna array. 
     On the basis of the technical solution of the antenna multiplexing system, the MIMO antenna array and the smart antenna array may both be vertically polarized antenna arrays. It is also possible that the MIMO antenna array is a dual-polarized antenna, and the smart antenna array is a vertically polarized antenna. 
     An embodiment of the present invention proposes an antenna multiplexing system in which a smart antenna and an MIMO antenna are organically combined. Antenna elements of a smart antenna array used in the TD-SCDMA system are divided into two groups, each respectively using for different purposes, one of which constitutes an MIMO antenna array and the other of which constitutes a smart antenna array. In an area with rich-scatter such as a city, two or more antenna elements with larger antenna element spacing, which have smaller dependence, may constitute an MIMO antenna array while a number of antenna elements with antenna element spacing smaller than or equal to λ/2 are still used as a smart antenna array to perform beam forming together, thereby forming an antenna multiplexing system of a smart antenna and an MIMO antenna. The smart antenna array may enhance the coverage capability of the service channel, and in the case of the equal total-power, the MIMO system may significantly increase the throughput of a user or decrease the bit error rate. Therefore, if the common channel is realized by the MIMO system, the coverage of the common channel may be further enhanced. By the embodiments of the invention, in the premise that the actual coverage capability of the TD-SCDMA system is further increased, the requirement of higher throughput of a user may also be satisfied. Particularly, the MIMO antenna system in the present invention may further satisfy the requirement of the evolution system in the future, such as an LTE and WiMax system. The requirement of application of the MIMO antenna and the smart antenna may be met by the same antenna-feeder system, and adaptive switching for a user between the MIMO antenna and the smart antenna may be achieved. 
     Further, an embodiment of the present invention also proposes an antenna multiplexing system including dual-polarized antenna elements. Since an existing antenna array may suffer from factors such as size, scale and distance of antenna elements and antenna element spacing, spacing of two antenna elements of a MIMO antenna array may not meet the requirement of dependence of MIMO application. In the embodiment of the present invention, the antenna elements constituting the MIMO antenna array are configured to be polarized in different manner to constitute the dual-polarized MIMO antenna array in the embodiment of the present invention. By using the feature of spatial fading characteristics of the mutually orthogonal antenna elements being independent, the requirement of dependence of an MIMO application is met, which expands application field and use environment of the embodiments of the present invention. 
     The technical solution of the embodiments of the present invention will be further described in detail with reference to the drawings and embodiments below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a structure of an antenna multiplexing system of a smart antenna and a Multiple-Input Multiple-Output antenna in an embodiment of the present invention; 
         FIG. 2  is a schematic diagram of a structure of a transmitting processing device in an embodiment of the present invention; 
         FIG. 3  is a schematic diagram of a structure of a determining module in an embodiment of the present invention; 
         FIGS. 4 and 5  are schematic diagrams of structures of a first embodiment of the present invention; 
         FIGS. 6 and 7  are schematic diagrams of structures of a second embodiment of the present invention; 
         FIG. 8  is a schematic diagram of a structure of a third embodiment of the present invention; 
         FIG. 9  is a schematic diagram of a structure of a fourth embodiment of the present invention; 
         FIG. 10  is a schematic diagram of a structure of a fifth embodiment of the present invention; 
         FIG. 11  is a schematic diagram of a structure of a sixth embodiment of the present invention; 
         FIG. 12  is a schematic diagram of a structure of a seventh embodiment of the present invention; 
         FIG. 13  is a flowchart of an antenna multiplexing method of a smart antenna and a Multiple-Input Multiple-Output antenna in an embodiment of the present invention; and 
         FIG. 14  is a flowchart of determining a transmitting mode and processing a data to be transmitted in an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE REFERENCE SIGNS 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 10: MIMO antenna array; 
                 20: smart antenna array; 
               
               
                 30: transmitting processing device; 
                 40: mobile terminal; 
               
               
                 31: MIMO antenna array 
                 32: smart antenna array transmitting 
               
               
                 transmitting processing 
                 processing module; 
               
               
                 module; 
               
               
                 33: determining module; 
                 331: transmitting mode determining 
               
               
                   
                 unit; 
               
               
                 332: data channel code, scrambling 
                 333: data spread spectrum 
               
               
                 code and intermediate code 
                 processing unit; 
               
               
                 assigning unit; 
               
               
                 334: multiplexing unit; 
                 335: transmitting mode control unit; 
               
               
                 336: ON/OFF controller. 
               
               
                   
               
             
          
         
       
     
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     An antenna multiplexing system of a smart antenna and a Multiple-Input Multiple-Output antenna in an embodiment of the present invention includes an MIMO antenna array and a smart antenna array. The smart antenna array includes a number of antenna elements, spacing of adjacent antenna elements being smaller than or equal to λ/2, wherein λ is a wavelength. The MIMO antenna array consists of at least two antenna elements with dependence satisfying requirements of MIMO application. In an embodiment of the present invention, to transmit a data to a target mobile terminal by combining the MIMO antenna array and the smart antenna array into one antenna multiplexing system, the MIMO antenna array is used to transmit a control information data or an MBMS service data to all mobile terminals in a cell to meet the requirement of balance of coverage capability of the TD-SCDMA system, and the smart antenna array is used to transmit a general service data to a single mobile terminal in the cell to reduce interference between users and enhance the coverage capability. 
       FIG. 1  is a schematic diagram of an implementing structure of an antenna multiplexing system of a smart antenna and a Multiple-Input Multiple-Output antenna in an embodiment of the present invention. As show in  FIG. 1 , the antenna multiplexing system of the smart antenna and the Multiple-Input Multiple-Output antenna includes an MIMO antenna array  10 , a smart antenna array  20  and a transmitting processing device  30 . The transmitting processing device  30  is configured for controlling the MIMO antenna array  10  and the smart antenna array  20  to transmit a data to a mobile terminal  40 . In the present implementing structure, the MIMO antenna array  10  consists of at least two antenna elements with dependence satisfying requirements of MIMO application, and the smart antenna array  20  includes a number of antenna elements, spacing of adjacent antenna elements being smaller than or equal to λ/2, wherein λ is a wavelength. 
       FIG. 2  is a schematic diagram of a structure of a transmitting processing device in an embodiment of the present invention. As shown in  FIG. 2 , the transmitting processing device  30  includes an MIMO antenna array transmitting processing module  31 , a smart antenna array transmitting processing module  32  and a determining module  33 . The determining module  33  is configured for determining a transmitting mode according to a type of a data to be transmitted, deciding assignment of a channel code, a spread spectrum code and an intermediate code in different modes, and controlling transmission of the data. The MIMO antenna array transmitting processing module  31  is configured to transmit a control information data or an MBMS service data to all mobile terminals in a cell through the MIMO antenna array  10  according to the transmitting mode determined by the determining module  33 , to meet the requirement of balance of coverage capability of the TD-SCDMA system. The smart antenna array transmitting processing module  32  is configured to transmit a general service data to a single mobile terminal in the cell through the smart antenna array  20  according to the transmitting mode determined by the determining module  33 , to reduce interference between users and enhance the coverage capability. 
       FIG. 3  is a schematic diagram of a structure of a determining module in an embodiment of the present invention. As shown in  FIG. 3 , the determining module  33  includes a transmitting mode determining unit  331 , a data channel code, scrambling code and intermediate code assigning unit  332 , a data spread spectrum processing unit  333 , a multiplexing unit  334 , a transmitting mode control unit  335  and an ON/OFF controller  336 . The transmitting mode determining unit  331  is configured to determine a transmitting mode according to a type of a data to be transmitted and transmit the transmitting mode to the data channel code, scrambling code and intermediate code assigning unit  332  and the transmitting mode control unit  335 . After receiving the transmitting mode, the data channel code, scrambling code and intermediate code assigning unit  332  selects and assigns a corresponding channel code, scrambling code and intermediate code to the data to be transmitted of different types according to the transmitting mode, and transmits the selected information to the data spread spectrum processing unit  333 . After receiving the selected information, the data spread spectrum processing unit  333  performs a spread spectrum processing on the data to be transmitted by using the selected channel code and scrambling code, and then transmits the data to be transmitted to the multiplexing unit  334 . The multiplexing (TDM) unit  334  multiplexes the data to be transmitted after spread spectrum processing and the corresponding intermediate code (Midamble) to constitute a burst. The transmitting mode control unit  335  and the ON/OFF controller  336  are configured to transmit the burst outward through a corresponding transmitting processing module. The ON/OFF controller  336  is connected to a transmitting path from the multiplexing unit  334  to the MIMO antenna array transmitting processing module  31  and the smart antenna array transmitting processing module  32  and is controlled by the transmitting mode control unit  335 . After receiving the transmitting mode from the transmitting mode determining unit  331 , the transmitting mode control unit  335  is able to transmit the burst through the MIMO antenna array transmitting processing module  31  or the smart antenna array transmitting processing module  32  by determining the ON/OFF of the controller  336  according to the transmitting mode. The ON/OFF controller  336  may be an ON/OFF switch or another switching device. 
     When the transmitting mode determined by the transmitting mode determining unit  331  according to the type of the data to be transmitted is to transmit a data to all mobile terminals in the cell by the MIMO antenna array, a MIMO antenna ON/OFF switch  336   a  in the controller  336  is turned on and a smart antenna ON/OFF switch  336   b  is turned off by the transmitting mode control unit  335 , so that the data can be transmitted outward through the MIMO antenna array transmitting processing module  31 . The data to be transmitted by the MIMO antenna array is a control information data or an MBMS service data. When the transmitting mode determined by the transmitting mode determining unit  331  according to the type of the data to be transmitted is to transmit a data to a single target mobile terminal in the cell by the smart antenna array, the MIMO antenna ON/OFF switch  336   a  in the controller  336  is turned off and the smart antenna ON/OFF switch  336   b  is turned on by the transmitting mode control unit  335 , so that the data can be transmitted outward through the smart antenna array transmitting processing module  32 . The data to be transmitted by the smart antenna array is a general service data. 
     An embodiment of the present invention proposes an antenna multiplexing system in which a smart antenna and an MIMO antenna are organically combined. Antenna elements of a smart antenna array used in the TD-SCDMA system are divided into to two groups, each respectively using for different purposes, one of which constitutes an MIMO antenna array and the other of which constitutes a smart antenna array. In an area with rich-scatter such as a city, two or more antenna elements with larger antenna element spacing, which have smaller dependence, may constitute an MIMO antenna array while a number of antenna elements with antenna element spacing smaller than or equal to λ/2 are still used as a smart antenna array to perform beam forming together, thereby forming an antenna multiplexing system of a smart antenna and an MIMO antenna. The smart antenna array may enhance the coverage capability of the service channel, and in the case of the equal total-power, the MIMO system may significantly increase the throughput of a user or decrease the bit error rate. Therefore, if the common channel is realized by the MIMO system, the coverage of the common channel may be further enhanced. By the embodiments of the invention, in the premise that the actual coverage capability of the TD-SCDMA system is further increased, the requirement of higher throughput of a user may also be satisfied. Particularly, the MIMO antenna system may further satisfy the requirement of the evolution system in the future, such as an LTE and WiMax system. In addition, it can be seen from the first embodiment to be described hereinafter, the system in the embodiments of the present invention may be achieved through certain improvement by sufficiently using the basic architecture of the antenna array of the existing TD-SCDMA system, without rebuilding the antenna-feeder system on a large scale. 
     Base on the above described implementing solution, the MIMO antenna array and the smart antenna array in the embodiments of the present invention may be implemented in a variety of implementing structures. 
     First Embodiment 
       FIGS. 4 and 5  are schematic diagrams of structures of the first embodiment of the embodiments of the present invention. As shown in  FIG. 4 , the first embodiment is an improvement on the basis of the smart antenna array used in the TD-SCDMA system. The number of the antenna elements is N. The antenna elements are divided into two groups, one of which consists of two antenna elements located at two end portions and is served as a MIMO antenna array  10 , and the other of which consists of N−2 antenna elements in the middle and is served as a directional smart antenna array, wherein N is an integer. The MIMO antenna array  10  and the smart antenna array  20  both are vertically polarized antenna arrays. 
     Since spacing of the antenna elements of the smart antenna array used in the TD-SCDMA system is smaller than or equal to λ/2, all N antenna elements satisfy the requirement of the smart antenna and may be used to perform beam forming. On the other hand, two antenna elements located at the far ends with the spacing of (N−1) λ/2, which have smaller dependence in an area with rich-scatter such as a city, may constitute the MIMO antenna array. For example, when an antenna with 8 antenna elements is used in the TD-SCDMA system, the spacing between two antenna elements of the MIMO antenna array is 3.5λ. It is indicated from an investigation that the spacing satisfies the requirement of dependence of the MIMO application in some environment. The requirement in the embodiment of the present invention may be satisfied by modifying the power amplifying of the two antenna elements. 
     As shown in  FIG. 5 , when the spacing between two antenna elements in the MIMO antenna array  10  satisfies the requirement of dependence of the MIMO application, the two antenna elements may also be arranged at the same end of the antenna array. The MIMO antenna array  10  and the smart antenna array  20  both are vertically polarized antenna arrays. 
     Second Embodiment 
       FIGS. 6 and 7  are schematic diagrams of structures of the second embodiment of the embodiments of the present invention, which are an improvement of the structure of the first embodiment. Two antenna elements of the MIMO antenna array  10  in  FIG. 6  are located at two end portions, and two antenna elements of the MIMO antenna array  10  in  FIG. 7  both are located at the same end portion. As shown in  FIGS. 6 and 7 , the MIMO antenna array  10  of the second embodiment consists of an antenna element  11  and an antenna element  12  located at the far end(s), and the smart antenna array  20  consists of the remaining N−2 antenna elements. The antenna element  11  and the antenna element  12 , which are orthogonally polarized, are dual-polarized antennas. The smart antenna array  20  is vertically polarized antenna array. 
     In the smart antenna array used in the existing TD-SCDMA system, due to the influence of factors such as size, scale and distance of antenna elements and antenna element spacing, two antenna elements of the MIMO antenna array sometimes may not meet the requirement of dependence of MIMO application. Accordingly, the second embodiment proposes an antenna multiplexing system of dual-polarized antenna elements, in which the antenna element  11  and the antenna element  12  constituting the MIMO antenna array are configured to be polarized in different manner. By using the mutually independent spatial fading characteristics of the two mutually orthogonal antenna elements, that is, the antenna element  11  and the antenna element  12 , the MIMO antenna array in the present embodiment may be constituted, and the requirement of dependence of an MIMO application may be satisfied. For example, the antenna element  11  which may be polarized by −45°, and the antenna element  12  which may be polarized by +45°, constitute dual-polarized antenna elements, so that the spatial fading characteristics of the two antenna elements are mutually independent, and thus the condition of MIMO application may be satisfied. All antenna elements of the smart antenna array  20  employ vertically polarize manner. 
     Third Embodiment 
       FIG. 8  is a schematic diagram of a structure of the third embodiment of the embodiments of the present invention. As shown in  FIG. 8 , the third embodiment is still based on the smart antenna array used in the TD-SCDMA system. The number of the antenna elements, that is, N, is kept constant. A first antenna element group  13  at one far end and a second antenna element group  14  at the other far end constitute the MIMO antenna array. N−4 antenna elements in the middle constitute the directional smart antenna array  20 . The spacing of two antenna elements in the first antenna element group  13  and the second antenna element group  14  should satisfy the requirement of dependence of the MIMO application, and the spacing of the N−4 antenna elements in the middle should be smaller than or equal to λ/2 to satisfy the requirement of application of the smart antenna. The antenna elements in the first antenna element group  13 , the second antenna element group  14  and the smart antenna array  20  all are vertically polarized antennas. Further, the first antenna element group  13  in the third embodiment may consist of three or more antenna elements, and the second antenna element group  14  may also consist of three or more antenna elements. 
     Fourth Embodiment 
       FIG. 9  is a schematic diagram of a structure of the fourth embodiment of the embodiments of the present invention, which is an improvement of the structure of the third embodiment. As shown in  FIG. 9 , the MIMO antenna array of the fourth embodiment includes a first antenna element group  13  and a second antenna element group  14  respectively located at two far ends. Each antenna element group includes two antenna elements. The two antenna elements, which are orthogonally polarized, are dual-polarized antennas. The smart antenna array  20  consists of N−4 antenna elements in the middle, which are vertically polarized antennas. 
     Due to the influence of factors such as size and scale of an antenna element group and antenna element group spacing, two antenna elements of the MIMO antenna array sometimes may not meet the requirement of dependence of MIMO application. Accordingly, the fourth embodiment divides the antenna elements constituting the MIMO antenna array into several pairs and ensures that spacing of the antenna element pairs satisfies the requirement of the MIMO application. Each pair of the antenna elements are configured to be polarized in different manner. By using the mutually independent spatial fading characteristics of the two mutually orthogonal antenna elements, it is ensured that not only the condition of the MIMO application is satisfied, but also the size of the antenna array is reduced. For example, the two antenna elements in the first antenna element group  13  or the second antenna element group  14  are respectively polarized by +45° and by −45°, and constitute dual-polarized antennas. 
     Fifth Embodiment 
       FIG. 10  is a schematic diagram of a structure of the fifth embodiment of the embodiments of the present invention. As shown in  FIG. 10 , the fifth embodiment is a combined antenna array structure. The number of antenna elements is N. The MIMO antenna array consists of an antenna element  15  and an antenna element  16 . The remaining N−2 antenna elements with spacing of λ/2 constitute a circular omnidirectional smart antenna array  20 . The MIMO antenna array and the smart antenna array  20  both are vertically polarized antenna arrays. 
     In the fifth embodiment, by making the spacing between the antenna element  15  and the antenna element  16  satisfy the condition of the MIMO application, that is, making the antenna spacing large enough, the MIMO antenna array may be constituted. The other N−2 antenna elements satisfy the requirement of the smart antenna and may be used to perform beam forming. 
     Base on the technical solution of the fifth embodiment, when the spacing between the antenna element  15  and the antenna element  16  is small, which does not satisfy the condition of the MIMO application, the antenna element  15  and the antenna element  16  may be configured to be dual-polarized antennas. By using the feature of their mutually independent spatial fading, the MIMO antenna array of the fifth embodiment is constituted and the requirement of dependence of the MIMO application is satisfied. The smart antenna array  20  is vertically polarized. 
     Also, the smart antenna array  20  of the fifth embodiment may also be directional smart antenna array configured in a linear layout. Further, the MIMO antenna array  10  and the smart antenna array  20  both may be vertically polarized antenna arrays, or the MIMO antenna array  10  is a dual-polarized antenna array, and the smart antenna array  20  is a vertically polarized antenna array, which will not described in detail here. 
     Sixth Embodiment 
       FIG. 11  is a schematic diagram of a structure of the sixth embodiment of the embodiments of the present invention. As shown in  FIG. 11 , the sixth embodiment is an improvement on the basis of a linear antenna array used in the TD-SCDMA system. The number of antenna elements is N. The antenna elements are divided into two groups, one of which consists of two antenna elements, that is, an antenna element  17  and an antenna element  18 , located at two end portions with dependence satisfying the requirement of the MIMO application and served as an MIMO antenna array  10 , and the other of which consists of all N antenna elements with spacing of adjacent antennas smaller than or equal to ½ wavelength and is served as a directional smart antenna array. 
     Seventh Embodiment 
       FIG. 12  is a schematic diagram of a structure of the seventh embodiment of the embodiments of the present invention. As shown in  FIG. 12 , the seventh embodiment is an improvement on the basis of a circular antenna array used in the TD-SCDMA system. The number of antenna elements is N. The antenna elements are divided into two groups, one of which consist of two antenna elements, that is, an antenna element  17  and an antenna element  18 , with dependence satisfying the requirement of the MIMO application and served as an MIMO antenna array, and the other of which consists of all N antenna elements with spacing of adjacent antennas smaller than or equal to ½ wavelength and is served as a omnidirectional smart antenna array. 
     The sixth and seventh embodiments may be used to implement an MIMO antenna system only by appropriately modifying the power amplifying of a part of antenna elements, on the basis of sufficient use of antenna structure of the TD-SCDMA system, so that the improvement of the system may be achieved on the basis of the protection of the existing invest to the largest extent. 
     It can be seen from the above described embodiments that, the power amplifying of the original antenna system may be kept or be appropriately modified according the requirement of actual application. The antenna multiplexing system is used under different conditions. In the embodiments of the present invention, the MIMO antenna array and the smart antenna array may be used to transmit data of different types, so as to satisfy the requirement of balance of the coverage capability of the TD-SCDMA system. The appropriate modification to the power amplifying of the original antenna system may increase the power of the MIMO antenna array, so that the total power thereof is equivalent to that of the original antenna system. Further, on the basis of the above described embodiments, the technical solutions illustrated in the first to the fifth embodiments may be combined to form a new technical solution, which will not described in detail here. 
       FIG. 13  is a flowchart of an antenna multiplexing method of a smart antenna and a Multiple-Input Multiple-Output antenna in an embodiment of the present invention. 
     In operation  1 , a transmitting mode is determined according to a type of a data to be transmitted and the data to be transmitted is correspondingly processed. 
     In operation  2 , an MIMO antenna array or a smart antenna array is controlled to transmit the data to a mobile terminal according to the transmitting mode. 
     The smart antenna array includes a number of antenna elements, and spacing of adjacent antenna elements is smaller than or equal to ½ wavelength. The MIMO antenna array consists of at least two antenna elements with dependence satisfying requirement of MIMO application. 
       FIG. 14  is a flowchart of determining a transmitting mode and processing a data to be transmitted in an embodiment of the present invention. In the above solution, the operation  1  includes: 
     Operation  141 , the transmitting mode is determined according to the type of the data to be transmitted; 
     Operation  142 , a corresponding channel code, scrambling code and intermediate code are selected and assigned to the data to be transmitted of different types according to the transmitting mode; 
     Operation  143 , spread spectrum processing is performed on the data to be transmitted according to the determined channel code and scrambling code; and 
     Operation  144 , the data to be transmitted after spread spectrum processing and the corresponding intermediate code are multiplexed to constitute a burst. 
     An embodiment of the present invention proposes an antenna multiplexing method in which a smart antenna and an MIMO antenna are organically combined. Antenna elements of a smart antenna array used in the TD-SCDMA system are divided into two groups, each respectively using for different purposes, one of which constitutes an MIMO antenna array and the other of which constitutes a smart antenna array. In an area with rich-scatter such as a city, two or more antenna elements with larger antenna element spacing, which have smaller dependence, may constitute an MIMO antenna array while a number of antenna elements with antenna element spacing smaller than or equal to λ/2 are still used as a smart antenna array to perform beam forming together, thereby forming an antenna multiplexing system of a smart antenna and an MIMO antenna. The smart antenna array may enhance the coverage capability of the service channel, and in the case of the equal total-power, the MIMO system may significantly increase the throughput of a user or decrease the bit error rate. Therefore, if the common channel is realized by the MIMO system, the coverage of the common channel may be further enhanced. By the embodiments of the invention, in the premise that the actual coverage capability of the TD-SCDMA system is further increased, the requirement of higher throughput of a user may also be satisfied. Particularly, the MIMO antenna system may further satisfy the requirement of the evolution system in the future, such as an LTE and WiMax system. 
     In an embodiment of the present invention, in the operation  141 , determining the transmitting mode is to determine the transmitting mode according to the type of the data to be transmitted, so that the MIMO antenna array or the smart antenna array transmits the data to corresponding users at different time, respectively. For example, when in the operation  141  the type of the data is a control information data, the data is transmitted at a first time slot through the MIMO antenna array, to improve coverage of the common channel. For example, when in the operation  141  the type of the data is a general service data, the data is transmitted through the smart antenna system, to enhance the coverage capability of the system. 
     In an embodiment of the present invention, the operation  142  may be implemented by a corresponding data channel code, scrambling code and intermediate code assigning unit. The operation  143  may be implemented by a corresponding data spread spectrum processing unit. The operation  144  may be implemented by a corresponding multiplexing (TDM) unit. A corresponding channel code, scrambling code and intermediate code are selected and assigned to the data to be transmitted according to the transmitting mode, and the selected information is transmitted to the data spread spectrum processing unit. After receiving the selected information, the data spread spectrum processing unit performs spread spectrum processing on the data to be transmitted by using the selected channel code and scrambling code, and then the data to be transmitted is transmitted to the multiplexing unit. The multiplexing (TDM) unit multiplexes the data after spread spectrum processing and the corresponding intermediate code (Midamble) to constitute a burst. The controlling the MIMO antenna array or the smart antenna array to transmit the data to the mobile terminal according to the transmitting mode in the operation  2  may be implemented by a corresponding control unit. 
     In employing the structure of the smart antenna array used in the existing TD-SCDMA system, due to the influence of factors such as size, scale and distance of antenna elements and antenna element spacing, the spacing between the antenna elements sometimes may not meet the requirement of dependence of MIMO application. Therefore, an embodiment of the present invention also proposes an antenna multiplexing method of dual-polarized antennas, in which two antenna elements constituting the MIMO antenna array are configured to be polarized in different manner. For example, one antenna element is polarized by −45°, and the other antenna element is polarized by +45°. By using the feature of the mutually independent spatial fading characteristics of the mutually orthogonal antenna elements, the dual-polarized MIMO antenna array are constituted, and the requirement of dependence of MIMO application is satisfied, which expands application field and use environment of the embodiments of the present invention. All antenna elements of the smart antenna array employ the same vertical polarization. In the antenna multiplexing method of the smart antenna and the Multiple-Input Multiple-Output antenna in the embodiment of the present invention, the MIMO antenna array and the smart antenna array may employ the structures illustrated in the aforementioned first to seventh embodiments, which will not be described in detail here. 
     Those skilled in the art should understand that, the implementation of part or all of operations of the above described method embodiments may be achieved by a hardware related to a instruction of a program. The program may be stored in a computer readable storage medium. While executing the program, the operations including the above described method embodiments are executed. The storage medium includes the medium that can store programs, such as a ROM, RAM, magnetic disk or optical disk. 
     Please note that, the above embodiments are merely used to describe the technical solutions in the embodiments of the present invention, but not limitative. Though the embodiments of the present invention are described in detail with reference to preferable embodiments, those skilled in the art should understand, the technical solutions in the embodiments of the present invention may be modified or equivalently replaced, without departing from the spirit and scope of the technical solutions in the embodiments of the present invention.