Antenna Pattern Deconvolution for Precise Incident Power Density Pattern Measurement

Future cellular and fixed wireless loops (FWL) systems employing highly directive base stations antennas (5 to 8 degrees beamwidth) and moderately directive subscribers' antennas (15 to 25 degrees beamwidth) exhibit unique radio propagation characteristics. These characteristics could be leveraged in a new air interface capable of achieving much higher capacities than those of classical vehicular cellular systems. The directive beams are expected to substantially reduce the interference levels thereby allowing multiple frequency reuse within an individual cell as well as some frequency reuse in adjoining cells. In order to assess the ultimate capabilities and limitations of such systems, as well as facilitate engineering design tradeoffs, a thorough characterization of the co-channel interference is needed. An important property of the environment of such systems is the interference caused by scattering of the signal from a subscriber transmitter into directions other than the direct line of sight between the subscriber and the base station. Such scattering results in fields incident on the base station at a variety of different angles. In particular, for multibeam base station applications scattering could arrive at the base station in the direction being used by a different beam, resulting in interference that is difficult to reduce by normal nulling techniques. Thus interference can be highly dependent on this incident power density pattern (IPDP) caused by scattering of the signal radiated from the subscriber.