| 摘要 |
A carrier aggregation communication system is presented in which a macro base station 5-1 is provided for communicating with a plurality of mobile communication devices 3-1 to 3-5 in a cellular communication system. The base station 5-1 operates one of more communication cells, primary cell 7, secondary cell 8, using respective component carriers C1 and (extension carrier) C2, and communicates sub-frames (30, figure 3), with each of the plurality of communication devices 3 within the cell(s), each comprising: the communication resources of a control region (31, figure 3) for communicating a control channel, and the communication resources of a data region (33, figure 3) for communicating a respective data channel. The base station 5-1 communicates a control channel having a first Demodulated Reference Signal DMRS sequence in a control region of some subframes and a control channel having a second DMRS sequence in a control region of other subframes. The second control channel may be transmitted using the extension component carrier C2 of macro secondary cell 8 in a radio beam focused spatially (using beam forming) in a direction 4-1, 4-2, 4-5, of a communication device 3. The first control channel (of the macro primary cell 7) may be transmitted omni-directionally throughout the cell(s). Pico cells 5-2, 5-3 may operate a respective pico primary cell 9-2, 9-3 on component carrier C2 and a respective secondary cell 10-2, 10-3 on component carrier C1. |
