The invention discloses a communication 
system volume expansion method, which belongs to the 
wireless communication field. The method comprises the following steps: firstly, determining the relative position information of each 
base station and adjacent base stations; determining the position information and the 
signal channel 
quality information of a mobile terminal in a subdistrict through received up-running signals; then, coordinating a 
forward wave beam between adjacent subdistricts at a next down-
running time interval by each 
base station according to the relative position information, the mobile terminal position information and the 
signal channel 
quality information to avoid the interference between the 
forward wave beams of the adjacent subdistricts; and finally, carrying out the wave beam molding for sending the coordinated 
forward wave beam as the down-running signals. At the same time, the invention adds an antenna patch in the 
base station, and the antenna patch is used for receiving the up-running signals for further expanding the volume. Compared with the prior art, the invention can avoid the interference between the 
signal wave beams, can improve the 
frequency spectrum utilization rate and the 
system volume, and simultaneously realizes the transmission of the up-running and down-running data at the same frequency and the same time interval is realized through adding the antenna patch, so the 
system volume is further and greatly improved.