Antenna diversity techniques

A communication system comprising:

• a spread spectrum transmitter connected to a transmitting antenna, said spread spectrum transmitter outputting a spread spectrum signal for transmission,
• a plurality of spatially separated receiving antennas each capable of generating an antenna signal in response to receiving said spread spectrum signal,
• a plurality of first mixers, each coupled to a single antenna signal,
• a plurality of frequency offset signals, each coupled to one of said first mixers, each of said frequency offset signals offset from the nearest other frequency offset signal by less than a predefined frequency amount less than the bandwidth of said spread spectrum signal,
• a combiner for combining an output from each of said first mixers into a backhaul signal,
• a backhaul cable having one end connected to said backhaul signal,
• a signal splitter connected to an opposite end of said backhaul cable, said signal splitter having as outputs a plurality of duplicate backhaul signals,
• a plurality of second mixers, each coupled to one of said duplicate backhaul signals,
• a plurality of inverse frequency offset signals, each an inverse of one of said frequency offset signals, and each one connected to an input of a second mixer, and
• a receiver coupled to an output from each of said second mixers.

A method for receiving a plurality of antenna signals, comprising the steps of:

• receiving a spread spectrum signal using a plurality of antennas, each antenna capable of generating an antenna signal in response thereto,
• generating a plurality of first frequency offset signals by adding a different frequency offset to each antenna signal from a plurality of frequency offsets, each first frequency offset signal differing in center frequency from the nearest other first frequency offset signal by less than a bandwidth of said received spread spectrum signal,
• combining said frequency offset signals into a backhaul signal,
• sending said backhaul signal over a cable,
• splitting, at an opposite end of said cable, said backhaul signal into a plurality of duplicate backhaul signals,
• adding one of said frequency offsets to each of said duplicate backhaul signals, and generating a plurality of second frequency offset signals thereby, and
• spread spectrum correlating each of said second frequency offset signals.

A method for receiving a plurality of antenna signals, comprising the steps of:

• receiving a spread spectrum signal using a plurality of antennas, and generating a plurality of antenna signals thereby,
• frequency isolating said plurality of antenna signals using a set of frequency offsets, thereby generating a plurality of frequency isolated antenna signals,
• combining said frequency isolated antenna signals for transmission over a cable,
• splitting an output of said cable into a plurality of duplicate cable signals,
• applying to each duplicate signal one frequency offset from said set of frequency offsets, thereby generating a plurality of frequency offset cable signals, and
• spread spectrum correlating each frequency offset cable signals.