Measurements of Randomly Placed Wireless Transmitters Used as an Array for Receivers Located Within the Array Volume With Application to Emergency Responders

Emergency responders often experience poor quality wireless communications due to the complex radio-frequency propagation environment encountered at a typical emergency response location, such as an apartment complex, office building, or other large building structure. Our previous theoretical analysis in conjunction with simulation studies suggests that optimizing arrays of randomly located wireless transmitters can provide a significant increase in the received signal level for a receiver located in the array volume. Here we present experimental results from the application of our initial algorithm in representative complex propagation environments. Several different scenarios are included in the experiments to demonstrate the effectiveness of the optimization approach in an environment that contains a variety of scattering objects. For the various scenarios, we observed at least a 7 dB median gain over a single transmitter when the array consists of four transmitters.