Implementation of an adaptive OFDMA PHY/MAC on USRP platforms for a cognitive tactical radio network

Cognitive radio is envisioned to solve the problem of spectrum scarcity in military networks and to autonomously adapt to rapidly changing radio environment conditions and user needs. Dynamic spectrum management techniques are needed for the coexistence of multiple cognitive tactical radio networks. Previous work has investigated the iterative waterfilling algorithm (IWFA) as a possible candidate to improve the coexistence of such networks. It has been shown that adding a constraint on the number of transmitter´s sub-channels improves the convergence of IWFA. In this paper, we propose an adaptive orthogonal frequency division multiple access (OFDMA) physical (PHY) and medium access control (MAC) for the coexistence of multiple cognitive tactical radio networks. The proposed scheme is implemented on universal software radio peripheral (USRP) platforms using Qt4/IT++ and the USRP hardware driver (UHD) application programming interface (API).