Patent ID: 7894781

Claim:
Apparatus comprising: a first antenna system comprising at least first and second directional antennas installed at respective fixed locations, a second antenna system comprising at least third and fourth antennas installed at respective fixed locations, said first and second directional antennas each being aimed at said third and fourth antennas, transmitter means for applying to said first antenna a first radio-frequency signal having energy in a particular frequency band and representing a first data stream, and for applying to said second antenna a second radio-frequency signal having energy in said particular frequency band and representing a second data stream, said first and second antennas being located with respect to each other and with respect to said second antenna system in such a way that at least two versions of said first radio-frequency signal, having substantially different phases, arrive at said second antenna system with substantially no multipath diversity and in such a way that at least two versions of said second radio-frequency signal, having substantially different phases, arrive at said second antenna system with substantially no multipath diversity, wherein said at least two versions of said first radio-frequency signal arrive at said third and fourth antennas, respectively, and wherein said at least two versions of said second radio-frequency signal arrive at said fourth and third antennas, respectively.