Reference Signal Design for Remote Interference Management in 5G New Radio

Abstract

In time division duplexing based mobile networks, under certain atmospheric ducting conditions, the uplink reception may be interfered by the downlink transmissions of remote base-stations (BSs) located hundreds of kilometers away. This paper addresses such remote interference problem in 5G new radio (NR) macro deployment context. Specifically, two potential reference signal (RS) designs for remote interference management (RIM) are described, together with receiver detection processing framework, to efficiently detect the interference due to multiple remote aggressor base-stations.The first signal structure, denoted as the one OFDM symbol (1OS) based RIM-RS, is building on the channel state information reference signals (CSI-RS) of 5G NR. The second candidate is referred to as the two OFDM symbol (2OS) based RIM-RS design, and builds on the design principles of LTE RIM-RS. The considered RIM-RS solutions are extensively analyzed and compared, with different parameterizations, in several realistic interference scenarios. The obtained results show that the 2OS RS design provides better RIM performance in scenarios where the number of interfering BSs is small. However, when the number of interfering BSs increases, the 1OS RS design starts to outperform the 2OS based approach. Additionally, it is shown that the 1OS RIM-RS provides smaller overhead and can be frequency multiplexed with the physical downlink shared channel.