Solutions to Data Congestion in Space; MmWave Communication for Nano-Satellites

This paper discusses some of the solutions to the issue of data congestion in Nano-satellite missions. The complexity of Nano-satellite missions has increased over the years, generating more data than ever and this paradigm shift has in-turn resulted in the need for larger downlink bandwidth requirements. The larger bandwidth's necessity and limited availability of frequency spectrum in lower frequencies spectrum has resulted in the problem of data congestion and invoked the need to investigate the use of mmWave frequency bands for Nano-satellite missions. In this paper, three use cases are discussed to demonstrate the need for using frequency bands higher than X-band and the communication strategy discussed in the use-cases are not restricted to the specific application mentioned in the use-cases but can be extended to similar applications. Irrespective of the frequency bands, there is a need to adapt standards such as DVB.S2 and DVB.S2X (Satellite digital broadcasting standard) that provide spectral efficient modulation schemes. Although these well-established standards are already used in satellite communications, this work proposes further optimization on the modulation schemes that helps improve efficiency of the transmitter front-end. A comparison between 16/32-QAM, 16/32-APSK, 16/32-oAPSK and the proposed 16/32-pAPSK (Polar-filtered Amplitude Phase Shift Keying) modulation schemes are discussed. Some of the practical challenges in using mmWave communications for nano-satellite missions are addressed in this paper with a study on the state-of-the-art mmWave semiconductor technology that are suitable for SSPA (Solid State Power Amplifier) design specifically for nano-satellite missions.