SIC Based Secondary Coexistence Over ATSC 3.0 Broadcast Channels

Coexistent communication, wherein multiple networks with dissimilar transmit waveform properties are deployed over the same band, has attracted a lot of recent attention, because of its high spectral efficiency. One of the most promising primary system candidates for such a deployment is over the ATSC 3.0 signaling based digital television broadcast transmission bands due to the excellent propagation characteristics. The throughput of the secondary system in such a deployment scenario suffers because of the high interference power from the broadcaster. Moreover, the secondary transmission parameters are chosen in such a way that the Quality of Service (QoS) of the primary network does not degrade. This paper investigates the feasibility of secondary network communication, under such a hostile scenario, using Successive Interference Cancellation (SIC) techniques. Various factors that contribute to the error in SIC systems are studied both analytically as well as through simulations. Based on the analysis, two schemes, namely, secondary slot size reduction and symbol blanking, are proposed for improving SIC performance. The performance of these schemes are analyzed in terms of the error vector magnitude of the primary network's estimated channel and its bit error rate. Through simulations it is also shown that, by using the proposed schemes, the secondary network is able to communicate at as low as -40 dB carrier-to-interference ratio.