Location
Cocoa Beach, Florida
Start Date
3-4-1967 12:00 AM
Description
An indirect approach toward increasing the data rate of a deep-space communication system involving the use of a relay satellite was studied. A simple frequency translation type repeater was assumed for the re lay satellite. In addition, the repeater was said to possess the characteristics of constant out put with signal - to -noise power sharing and also suppression effects due to the repeater's inherent nonlinearity. The data rate capability of the indirect approach was compared with that of the direct one (no relay satellite) . In the comparison the earth terminal characteristics were assumed to be the same for both approaches. The results were ex pressed in terms of the merit f unction M( r), which i s the ratio of the signal - to noise spectra l density of the direct approach to that of the indirect one.
The calculations of the merit function indicate that the data rate improvement possesses a limiting value given by the ratio of the effective radiated power of the relay satellite to that of the mission vehicle of the direct link. Due to the relay satellite power sharing characteristics it should be placed closer to the mission vehicle than to the earth, and there also exist s between the earth station and the relay satellite a minimum desirable separation beyond which the limiting value of improvement can be obtained.
An Approach Toward Increasing the Data Rate of Future Deep Space Communication Systems
Cocoa Beach, Florida
An indirect approach toward increasing the data rate of a deep-space communication system involving the use of a relay satellite was studied. A simple frequency translation type repeater was assumed for the re lay satellite. In addition, the repeater was said to possess the characteristics of constant out put with signal - to -noise power sharing and also suppression effects due to the repeater's inherent nonlinearity. The data rate capability of the indirect approach was compared with that of the direct one (no relay satellite) . In the comparison the earth terminal characteristics were assumed to be the same for both approaches. The results were ex pressed in terms of the merit f unction M( r), which i s the ratio of the signal - to noise spectra l density of the direct approach to that of the indirect one.
The calculations of the merit function indicate that the data rate improvement possesses a limiting value given by the ratio of the effective radiated power of the relay satellite to that of the mission vehicle of the direct link. Due to the relay satellite power sharing characteristics it should be placed closer to the mission vehicle than to the earth, and there also exist s between the earth station and the relay satellite a minimum desirable separation beyond which the limiting value of improvement can be obtained.
