Link Budget for NTNU Test Satellite

The NTNU Test Satellite, NUTS, is the project of Norwegian University of Science and Technology developed in the academic ambience of CubeSat scheme. Outset had placed three years ago and the plan is to be launched by 2014. Communication system has been previously studied and frequencies allocations were defined on VHF and UHF bands, the channel will carry information of TTC combinations under the NUTS constraints were studied by using block codes. Bit Error Probability by transmitting a coded message was obtained involving codes Hamming and Reed Solomon, scenario was varied for different bandwidth and symbol rate. Those parameters had an important role for this student satellite and restrictions implied. Finally, visibility time was obtained, defined parameters for transmission and devices chosen complaining with link budget results were used as input data on Satellite Tool Kit software, simulations of tracking were done in a period of one week, data generated related to access time was read in Matlab script and visibility time for different height computed. A previous study of the radio packet with AX.25 protocol was used as a base to estimate the transferred images per day that can be reached when different elevation angles are chosen as minimum. Link margin decreases at low elevation angles, then, a balance between modulation and error control, should be found. Different suitable scenarios are proposed here.