Systems and methods for distributed antenna system reverse path summation using signal-to-noise ratio optimization

A remote antenna unit for a distributed antenna system having a plurality of remote antenna units, the remote antenna unit comprising:

• a first module coupled to at least one antenna, the first module including a converter that digitally samples a wireless RF signal received at the at least one antenna to produce a first stream of digital samples;
• a second module coupled to the first module and an incoming signal interface, the second module including a summer that produces a composite signal by summing digital samples from the first stream of digital samples with digital samples based on a second stream of digital samples received via the incoming signal interface;
• wherein the first module adjusts a gain of the first stream of digital samples by a first factor that normalizes a first uplink noise floor for the remote antenna unit based on a noise floor normalization value established for the distributed antenna system to match a lowest noise floor of all of the plurality of remote antenna units of the distributed antenna system, wherein the lowest noise floor is a performance characteristic of a remote antenna unit having a lowest noise power of all of the plurality of remote antenna units of the distributed antenna system;
• wherein the first module further adjusts the gain of the first stream of digital samples by a scaling factor based on a composite maximum host peak power for a host unit for the distributed antenna system, wherein the scaling factor is the same for each of the plurality of remote antenna units in the distributed antenna system, wherein the scaling factor changes when there is a change in a number of remote antenna units in the plurality of remote antenna units.

A distributed antenna system having optimized reverse path summation, the distributed antenna system comprising:

• a host unit;
• a plurality of remote antenna units coupled to the host unit including at least a first remote antenna unit having a first noise that is the lowest noise floor of any of the plurality of remote antenna units;
• wherein an uplink noise floor for the plurality of remote antenna units is normalized to a noise floor normalization value based on the first noise floor of the at least a first remote antenna unit that is the lowest noise floor of any of the plurality of remote antenna units, wherein the uplink noise floor for the plurality of remote antenna units is normalized such that the noise power of each of the plurality of remote antenna units is adjusted to match the first noise floor that is the lowest noise floor of any of the plurality of remote antenna units, wherein the lowest noise floor is a performance characteristic of the at least a first remote antenna unit having a lowest noise power;
• and
• wherein an uplink output gain for each of the plurality of remote antenna units is scaled by a scaling factor that is based on a composite maximum host peak power for the host unit, wherein the scaling factor is the same for each of the plurality of remote antenna units, wherein the scaling factor changes when there is a change in a number of remote antenna units in the plurality of remote antenna units;
• wherein each of the plurality of remote antenna units adjusts a gain of digital samples generated from wireless RF signals received at each respective remote antenna unit, based on the noise floor normalization value and the scaling factor, prior to summing of said digital samples with other digital samples received at each respective remote antenna unit.