A data modulation method, adapted to a transmitter having an antenna array including N antennas in a multi-antenna communication system, wherein N>1, and the method comprising: receiving a plurality of symbols to be transmitted; mapping each of the symbols as a L-dimensional coordinate, so as to divide the N antennas into L non-overlapping antenna groups in response to the L-dimensional coordinate, wherein 1 < L < N;, and each of the L non-overlapping antenna groups comprises at least K antennas, wherein K≥1; choosing one activating antenna from the K antennas in each of the non-overlapping antenna groups according to the L-dimensional coordinate of the symbols; and transmitting modulated signal by using the chosen activating antenna in each of the L non-overlapping antenna groups, wherein a signal modulation scheme used on each of the L chosen activating antennas is determined in accordance to the L-dimensional coordinate, the data modulation method being characterized in that the step of choosing one activating antenna from the K antennas in each of the L non-overlapping antenna groups according to the L-dimensional coordinate of the symbols comprises: assigning the L non-overlapping antenna groups to respectively represent the L dimensions of the L-dimensional coordinate of the symbols; and based on the L-dimensional coordinate of the symbols, determining one activating antenna in each of the L non-overlapping antenna groups according to the coordinate value in the dimension that the L non-overlapping antenna groups corresponding to. receiving a plurality of symbols to be transmitted; mapping each of the symbols as a L-dimensional coordinate, so as to divide the N antennas into L non-overlapping antenna groups in response to the L-dimensional coordinate, wherein 1 < L < N;, and each of the L non-overlapping antenna groups comprises at least K antennas, wherein K≥1; choosing one activating antenna from the K antennas in each of the non-overlapping antenna groups according to the L-dimensional coordinate of the symbols; and transmitting modulated signal by using the chosen activating antenna in each of the L non-overlapping antenna groups, wherein a signal modulation scheme used on each of the L chosen activating antennas is determined in accordance to the L-dimensional coordinate, the data modulation method being characterized in that the step of choosing one activating antenna from the K antennas in each of the L non-overlapping antenna groups according to the L-dimensional coordinate of the symbols comprises: assigning the L non-overlapping antenna groups to respectively represent the L dimensions of the L-dimensional coordinate of the symbols; and based on the L-dimensional coordinate of the symbols, determining one activating antenna in each of the L non-overlapping antenna groups according to the coordinate value in the dimension that the L non-overlapping antenna groups corresponding to. assigning the L non-overlapping antenna groups to respectively represent the L dimensions of the L-dimensional coordinate of the symbols; and based on the L-dimensional coordinate of the symbols, determining one activating antenna in each of the L non-overlapping antenna groups according to the coordinate value in the dimension that the L non-overlapping antenna groups corresponding to.