this invention provides a mobile communication system which expanded the operation limitation of the heretofore adopted mobile communication systems and improved the spectrum efficiency greatly . a data transmission method for use in the mobile communication system of the present invention includes means for channel pluralizing by which to expand the shannon limit and means for interference reduction by which to expand the interference limit . more specifically , a transmitting module comprises m units of modulators and l units of transmitting antennas , generates l units of signals by multiplying m units of modulated signals by a complex matrix consisting of m × l units of elements , and transmits the l units of signals from the l units of transmitting antennas .