Method for transmitting digital data over a communication channel, between: - a transmitter base comprising transmission antennas of index n, where n is between 1 and N and N is an integer greater than or equal to 1, and - receivers of index k, where k is between 1 and K and K is an integer greater than or equal to 1, each comprising at least one receiving antenna, a method wherein a signal carrier of frequency f o is used to transport the digital data in the communication channel, and sub-carriers are used of index m, where m is between 1 and M and M is an integer greater than or equal to 1, adapted to transport K streams of digital data s k in parallel from the transmitter base, each stream of digital data s k being intended for each receiver of index k, wherein said method comprises the following steps: each of the K streams of digital data s k are transformed into M parallel streams s k (m) of symbols, each of the parallel streams being intended for a sub-carrier of index m, N.M complex symbols t n (m) are calculated from the K.M symbols s k (m), by: t n m = ∑ k = 1 K α k. H k, n * m. s k m where * denotes a complex conjugate, H k, n (m) is a complex value estimating the transfer function of the communication channel between the transmission antenna n and the receiving antenna k at a corresponding frequency of the sub-carrier m, and α k is a normalization coefficient, N multi-carrier modulations of the complex symbols t n (m) are performed, where m is between 1 and M, to produce N transmission signals v n (t), each transmission signal v n (t) being intended for a transmission antenna n, and all the multi-carrier modulations being synchronous with each other, and each transmission signal v n (t) in the communication channel is transmitted by the transmission antenna n of the transmitter base. - a transmitter base comprising transmission antennas of index n, where n is between 1 and N and N is an integer greater than or equal to 1, and - receivers of index k, where k is between 1 and K and K is an integer greater than or equal to 1, each comprising at least one receiving antenna, a method wherein a signal carrier of frequency f o is used to transport the digital data in the communication channel, and sub-carriers are used of index m, where m is between 1 and M and M is an integer greater than or equal to 1, adapted to transport K streams of digital data s k in parallel from the transmitter base, each stream of digital data s k being intended for each receiver of index k, wherein said method comprises the following steps: each of the K streams of digital data s k are transformed into M parallel streams s k (m) of symbols, each of the parallel streams being intended for a sub-carrier of index m, N.M complex symbols t n (m) are calculated from the K.M symbols s k (m), by: t n m = ∑ k = 1 K α k. H k, n * m. s k m where * denotes a complex conjugate, H k, n (m) is a complex value estimating the transfer function of the communication channel between the transmission antenna n and the receiving antenna k at a corresponding frequency of the sub-carrier m, and α k is a normalization coefficient, N multi-carrier modulations of the complex symbols t n (m) are performed, where m is between 1 and M, to produce N transmission signals v n (t), each transmission signal v n (t) being intended for a transmission antenna n, and all the multi-carrier modulations being synchronous with each other, and each transmission signal v n (t) in the communication channel is transmitted by the transmission antenna n of the transmitter base. each of the K streams of digital data s k are transformed into M parallel streams s k (m) of symbols, each of the parallel streams being intended for a sub-carrier of index m, N.M complex symbols t n (m) are calculated from the K.M symbols s k (m), by: t n m = ∑ k = 1 K α k. H k, n * m. s k m where * denotes a complex conjugate, H k, n (m) is a complex value estimating the transfer function of the communication channel between the transmission antenna n and the receiving antenna k at a corresponding frequency of the sub-carrier m, and α k is a normalization coefficient, N multi-carrier modulations of the complex symbols t n (m) are performed, where m is between 1 and M, to produce N transmission signals v n (t), each transmission signal v n (t) being intended for a transmission antenna n, and all the multi-carrier modulations being synchronous with each other, and each transmission signal v n (t) in the communication channel is transmitted by the transmission antenna n of the transmitter base.