One written test (2 mandatory technical papers and one aptitude digital, analog, signals processing and firmware ) There were 3 technical rounds, one aptitude round and one ceo round. First one took for about half an hour. Second one 45 mins. Third one 30 mins. Ceo round was for 45 mins. First 2 technical mainly asked about signals and systems concepts like dft, fourier analysis, decision boundaries map, mal, error probability, comparison of 16 qpsk, 16 qam constellation diagrams in terms of power and detection abilities, comparison of symmetrical and asymmetrical constellation diagrams. 3rd technical mainly of digital and analog communication, band pass sampling, basics of ofdm, info theory.