Software Defined Radios for CubeSat Applications: A Brief Review and Methodology
CubeSats have revolutionized the way scientists and students perceive space. The majority of CubeSat communication is greatly limited by the AX.25 standards, the small communication window, the available transmission power, and the available bandwidth at VHF/UHF band. As a result, CubeSat radios could only establish low data rate links which restrict the communication capabilities of a CubeSat mission. In this paper, a brief review of current Software Defined Radios used in space missions is given. In addition, two different design methodologies for Software Defined Radios for CubeSats are proposed that can be used as guideline for CubeSat developers. Finally, a High Data Rate Software Defined Radio for the UOW CubeSat project is presented that address all the above limitations. The radio operates at S-band, employs Quadrature Amplitude Modulation with a maximum data rate of 60Mbps consuming 2.6 Watts in transmit mode and 0.4 Watts in receive mode. The digital signal processing functions and the mode control of the radio are orchestrated by a Field Programmable Gate Array System-on Chip. The analog Radio Frequency domain is accommodated by a 4-layer Printed Circuit Board with dimensions of 92mm x 88mm. The goal of the UOW CubeSat radio is an adaptive, on-flight reconfigurable communication platform that will revolutionize the current communication capabilities of the CubeSats and expand nanosatellites mission perspectives.