Distributed antenna system for MIMO technologies

摘要

The invention is directed to a method and system for supporting MIMO technologies which can require the transport of multiple spatial streams on a traditional Distributed Antenna System (DAS). According to the invention, at one end of the DAS, each spatial stream is shifted in frequency to a pre-assigned band (such as a band at a frequency lower than the native frequency) that does not overlap the band assigned to other spatial streams (or the band of any other services being carried by the DAS). Each of the spatial streams can be combined and transmitted as a combined signal over a common coaxial cable. At the other “end” of the DAS, the different streams are shifted back to their original (overlapping) frequencies but retain their individual “identities” by being radiated through physically separate antenna elements.

主权项

1. A distributed antenna system for distributing MIMO signals for at least one MIMO service in a distributed antenna system (DAS), comprising:
a) a remote unit configured to receive and distribute non-overlapping frequency MIMO downlink signals of at least one MIMO service; b) at least one antenna unit configured to receive the non-overlapping frequency MIMO downlink signals of the at least one MIMO service and frequency shift the non-overlapping frequency MIMO downlink signals into native frequency MIMO downlink signals; c) a single coaxial cable used to carry the non-overlapping frequency MIMO downlink signals of the at least one MIMO service between the remote unit and the at least one antenna unit; wherein the at least one antenna unit is operatively coupled to at least two MIMO antennas, the at least one antenna unit is configured to transmit the native frequency MIMO downlink signals via the at least two MIMO antennas.