DESIGN STUDY FOR A CDMA-BASED LEO SATELLITE NETWORK - DOWNLINK SYSTEM-LEVEL PARAMETERS

The performance analysis of a new concept of a code-division multiple- access (CDMA) based low earth orbit (LEG) satellite network for mobile satellite communications is presented and discussed, The starting poi nt was to analyze the feasibility of implementing multisatellite and m ultipath diversity reception in a CDMA network for LEO satellites, The results will be used to specify the design parameters for a system ex perimental test bed, Due to the extremely high Doppler, which is chara cteristic of LEO satellites, code acquisition is significantly simplif ied by using a continuous wave (CW) pilot carrier for Doppler estimati on and compensation, The basic elements for the analysis presented in this paper are: the channel model, the pilot carrier frequency estimat ion for Doppler compensation, and multipath and multisatellite diversi ty combining.