Analysis of Space Diversity Techniques for EHF (Extremely High Frequency) Satellite Downlinks.

This study investigated some of the diversity combining techniques that can be used with a space diversity downlink reception configuration to overcome the attenuation effects of rainfall. The diversity combining techniques selected for development and analysis were selection, equal gain, and maximal ratio combining. Each of these techniques were considered with two different digital signalling schemes, 8-ary phase-shift keying PSK and differentially encoded quadrature PSK DQPSK, to form six distinct diversity techniquesignaling scheme combinations. The analysis was accomplished by deriving the probability of bit error functions for 8-ary PSK and DQPSK and by developing the probability of density functions for each diversity technique under the assumption of a slowly fading Rayleigh channel. By taking the integral from zero to infinity of the product of the two functions for each diversity techniquesignaling scheme combination, the probability of bit error was calculate for each specified combination. Originator-supplied keywords include Communications satellites, and Diversity reception.