Propagation measurements for satellite services into buildings

The structure of the slant path signal strength at frequencies from 500 MHz to 3000 MHz has been measured inside a series of buildings using a tower-mounted transmitter. The mean signal level was found to decrease with a rate of about 1 to 5 dB/GHz, depending on construction. For LEO satellite systems using CDMA, with up/down links at L/S band, one critical issue is the correlation bandwidth which determines whether up-link power control can be instituted based on down-link measurements. While not required for one-way services, power control is critical for two-way operations. To help answer this question, simultaneous slant path fade measurements were made at about 1600 and 2500 MHz into several buildings, also using a tower. Fade differences between L- and S-Band exhibited a normal distribution with means near 0 dB and standard deviations of about 7.5 dB. To evaluate the effect of LEO satellite reception in buildings without expecting user cooperation, fade measurements were obtained at a frequency near 1630 MHz inside several large high-rise office buildings. The transmissions were made from aircraft flying in a trajectory simulating LEO passes. The statistical properties of the signals after penetrating into buildings are of interest and will be presented. The statistics of the signals outside of a building could be Rayleigh, Riccan or Loo, depending upon the building's environment. However, analysis of the measurements taken inside suggest that a lognormal signal amplitude distribution applies in scenarios where a directive receiving antenna is not located near a window with a line-of sight view of the.