Experimental Study of Constellation Rotation in NOMA Wi-Fi Networks

Non-orthogonal multiple access is promising way to increase the efficiency of Wi-Fi networks in the downlink. With this technology, an access point can simultaneously transmit data to various devices using the same time-frequency resource. The decoding efficiency of a signal transmitted using non-orthogonal multiple access depends not only on the channel conditions between devices but also on the structure of the composite signal. In this paper, we present a testbed that uses a constellation rotation to decrease the influence of the phase noise and show that the constellation rotation increases the decoding probability of a NOMA Wi-Fi signal.