Implementation of adaptive modulation for A/G communication system using ZeptoSDR

Software Defined Radio (SDR) technology is gaining popularity because of its capability to implement different applications with almost no hardware changes. Such a solution can decrease size, weight, power and cost requirements of avionics systems. This paper presents an experimental implementation of adaptive modulation technique for wideband air-to-ground (A/G) communication systems using Nutaq´s ZeptoSDR software defined radio platform. The system implementation provides a transmission of a real time captured video equipped by an adaptive modulation technique. The system autonomously chooses the most suitable modulation among BPSK, QPSK, 8PSK, 16QAM and 64QAM based on the estimation of link quality measured by the signal to noise ratio (SNR) in real time.