A mobile communications system, comprising: - a plurality of base station apparatuses (2011, 2021, 2031, 10000) which are located at geographically dispersed locations and perform a wireless communication with a mobile device; - a maximum ratio combining means (305, 3051) which is connectable with said plurality of base station apparatuses for a communication via a first communication line and performs maximum ratio combining processing based on information corresponding to a received signal from said mobile device, said information being transmitted from said plurality of base station apparatuses; - a selection combining means (306, 3061) which is connectable with said plurality of base station apparatuses for a communication via a second communication line and performs selection combining processing based on information corresponding to a received signal from said mobile device, said information being transmitted from said plurality of base station apparatuses; and - a selection means (10100, 10101, 10201, 10300, 307) which selects one or both of said maximum ratio combining means and said selection combining means according to at least one of an external factor and a change in number and location of mobile devices being distributed under communication that exists in a coverage area of said plurality of base station apparatuses with which said mobile device performs a wireless communication, when signal combining is performed based on said information corresponding to said received signal from said mobile device, said information being transmitted from said plurality of base station apparatuses, in response to reception of a wireless signal by said plurality of base station apparatuses, said wireless signal being transmitted from one mobile device, and - wherein said selection means selects both of said maximum ration combining means and said selection combining means, a combining result of said maximum ratio means is transmitted to said selection combining means, and - wherein said plurality of base station apparatuses request said selection means to change a destination of said information corresponding to said received signal from said mobile device to one or both of said maximum ratio combining means and said selection combining means according to said change in number and location of mobile devices being distributed under communication in the coverage area. - a plurality of base station apparatuses (2011, 2021, 2031, 10000) which are located at geographically dispersed locations and perform a wireless communication with a mobile device; - a maximum ratio combining means (305, 3051) which is connectable with said plurality of base station apparatuses for a communication via a first communication line and performs maximum ratio combining processing based on information corresponding to a received signal from said mobile device, said information being transmitted from said plurality of base station apparatuses; - a selection combining means (306, 3061) which is connectable with said plurality of base station apparatuses for a communication via a second communication line and performs selection combining processing based on information corresponding to a received signal from said mobile device, said information being transmitted from said plurality of base station apparatuses; and - a selection means (10100, 10101, 10201, 10300, 307) which selects one or both of said maximum ratio combining means and said selection combining means according to at least one of an external factor and a change in number and location of mobile devices being distributed under communication that exists in a coverage area of said plurality of base station apparatuses with which said mobile device performs a wireless communication, when signal combining is performed based on said information corresponding to said received signal from said mobile device, said information being transmitted from said plurality of base station apparatuses, in response to reception of a wireless signal by said plurality of base station apparatuses, said wireless signal being transmitted from one mobile device, and - wherein said selection means selects both of said maximum ration combining means and said selection combining means, a combining result of said maximum ratio means is transmitted to said selection combining means, and - wherein said plurality of base station apparatuses request said selection means to change a destination of said information corresponding to said received signal from said mobile device to one or both of said maximum ratio combining means and said selection combining means according to said change in number and location of mobile devices being distributed under communication in the coverage area.