Co-Channel Interference in High Capacity Fixed Wireless Loops(FWL)

The increased demand for fast internet and other data services resulted in severe bandwidth requirements for future fixed wireless loop (FWL) systems. These requirements could be met through very efficient re-use of the allocated bandwidth. Such a re-use could possibly be achieved via the utilization, at the base station, of highly directive (5degrees to 10degrees) scanning beams in conjunction with fixed directive (15degrees to 25degrees) subscriber antennas beams. At each base station, multiple and non-overlapping scanning beams, with low sidelobes, simultaneously operating at the same frequency band can increase the frequency re-use many-fold. Such beams could help to reduce delay spread and co-channel interference. Scattering, diffraction, and multiple reflections of transmission from subscribers in actual environments could result in a wide angular spectrum of power incident on base station, referred to hereafter as the Incident Power Density Patter (IPDP). We discuss the IPDP and some of its important S/I implications for proper system capacity simulations.