A radio access system with distributed antennas

The paper analyzes a radio access system that has multiple antennas spatially distributed throughout the coverage area of a radio port, instead of a single antenna at the radio port. The same signal is simulcast by each antenna in the coverage area of the port. The signals at a given port could be multiplexed and modulated for radio transmission at a single node, then transmitted on a coaxial cable bus to and from the distributed port antennas. Frequency translation and RF amplification may need to be performed at each antenna, except for indoor applications with short coaxial cables. The paper presents calculations of signal to interference ratios (SIR) of ports with distributed antennas. It is shown that the use of distributed antennas can substantially increase the SIR above a system with a single antenna per port, and this increase is quantified