Performance Analysis of O-QPSK with various types of Amplifier non-linearities in Inter- satellites Communications Links

The need for low cost remote sensing is on the rise and cube satellite remote sensing has been adopted by various space agencies. Newer applications are envisaged where in the remote sensing data reaches the authorized user directly thereby reducing the latency or turn-around time involved in the traditional Ground station based acquisition of remote sensing data from satellites. The cube satellite constellation is envisaged by various space agencies for enhanced revisit and area of imaging. But the cube-satellites are DC power limited and cannot possess required higher computational power. Hence in this paper a Cubesat-Microsat constellation is proposed with corresponding Intersatellite links. The Microsat acting as Master satellite acquires the data from various cube-satellites, process the data and in-turn will transmit the data via LEO-GEO Intersatellite link directly to the user. This eliminates the stringent tracking requirements for a Satellite in the Low earth orbit. The intersatellite links proposed for the constellation is bound to suffer with various types of Amplifier non linearities and Doppler effects. In this paper the cumulative effect of Doppler and Amplifier Non-linearities on the performance of OQPSK modulated signal is presented in this paper.