Distributed antenna system for MIMO technologies

A method for conveying a plurality of MIMO spatial streams over a distributed antenna system comprising:

• receiving from a base station, each downlink MIMO spatial stream having a native frequency;
• converting each of the downlink MIMO spatial streams from the native frequency to a different, non-overlapping frequency band;
• combining each of the downlink MIMO spatial streams to form a combined downlink signal;
• transmitting the combined downlink signal to a base unit;
• transmitting the combined downlink signal to a plurality of remote units over a separate communication medium connecting the base unit to each remote unit;
• providing a multiplexer adapted for connecting the remote unit with a plurality of antenna units and transmitting the combined downlink signal to each of the antenna units over an antenna unit communication medium;
• separating, at respective ones of the antenna units, the combined downlink signal into each of the downlink MIMO spatial streams converting each of the downlink MIMO spatial streams to the native frequency band;
• and transmitting each of the downlink MIMO spatial streams through an associated antenna, at respective ones of the antenna units, the combined downlink signal into each of the downlink MIMO spatial streams converting each of the downlink MIMO spatial streams to the native frequency band;
• and transmitting each of the downlink MIMO spatial streams through an associated antenna.

A distributed antenna system comprising:

• a radio interface unit adapted to receive a plurality of downlink MIMO spatial streams from
• at least one base station, the radio interface unit including at least one mixer adapted for converting each of the downlink MIMO spatial streams from a native frequency bank to a different, non-overlapping frequency bank and a downlink duplexer adapted for combining each of the downlink MIMO spatial streams to form a combined downlink signal on to a common transmission medium;
• a base unit adapted to receive the combined downlink signal over the common transmission medium, and for transmitting the combined downlink signal to a plurality of remote units over a separate communication medium connecting the base unit to each remote unit;
• each remote unit including a multiplexer adapted for connecting the remote unit with a plurality of antenna units and for transmitting the combined downlink signal to each of the antenna units over an antenna unit communication medium;
• a plurality of MIMO antennae;
• a de-duplexer adapted for separating the combined downlink signal into each of the downlink MIMO spatial streams;
• and
• at least one downlink mixer adapted for converting each of the downlink MIMO spatial streams to the native frequency band.