Patent ID: 6922570

Claim:
Wireless radiofrequency data system comprising: a base-station comprising N first sets and a signal processing-unit connected with each of the N first sets for processing signals received and to be transmitted by the N first sets, and M seconds sets with N greater than M, wherein each first set and each second set comprises a transmitter- and receiver-unit having at least one antenna and provided with a transmitter and a receiver that operate on essentially the same radiofrequency or radiofrequency-band, wherein the signal processing-unit is provided with an inputport for inputting M signals Q to be received by the respective M second sets and comprises information about transfer-functions H of radiofrequency signals from each of the antennas of the N first sets to each of the antennas of the M second sets and/or vice versa, and wherein the signal processing-unit processes the signals received and to be transmitted by the N first sets on the basis of said transfer functions H such that for each second set of a plurality of the M second sets an individual communication channel is formed with the base-station wherein these communication channels are generated simultaneously and separately from each other, wherein the processing unit is arranged to process the M signals Q in combination on the basis of information of the transfer-functions H to establish M of said simultaneous communication channels by processing on the basis of the information about the transfer-functions H, the M signals Q to obtain the N transmit-signals R, to be transmitted by the first sets to the second sets, according to R=P D Q, (A) resulting in that the M signals Q are received separately by the respective second sets if the second sets each receive the N transmit-signals, where P D =[H*(H*H) −1 ] T is the pseudoinverse of H T and where H* is the complex conjugated and transposed of H, wherein H is a complex [N*M] matrix containing transfer functions h ij (i=1, . . . , N; j=, . . . , M), wherein h ij is the transfer function for transmission from the i th second set of the M second sets to the i th first set of the N first sets, and where Q is a complex M dimensional vector [Q 1 , Q 2 , . . . Q j , . . . , Q m ] wherein O j is the signal to be transmitted to the j th second set of the M second sets and where R=[R 1 , R 2 , . . . R j , . . . R N ] T wherein R i is the transmit-signal to be transmitted by the i th first set of the N first sets.