2019/06 95 p.
RAN4 requirements designed to ensure co-existence between different networks operating on adjacent carriers in the same band (i.e. ACLR, ACS) were developed in release 15 under the assumption of synchronized TDD. Interference between adjacent carriers is mitigated as long as all networks apply uplink and downlink at the same occasions.
Dynamic TDD describes a mode of operation in which a network adapts the DL/UL subframe pattern according to traffic conditions. If different nodes in the same network apply DL and UL at different times, then interference between different UEs and different BS occurs. RAN1 has specified measurements to enable co-channel Cross Link Interference (CLI) mitigation within the same network.
Dynamic TDD also causes interferers between networks on adjacent channels. Unlike the co-channel case, interference between adjacent channel networks cannot be coordinated. Instead, the interference is mitigated by transmitter and receiver selectivity (ACLR and ACS) as analogue filtering is not generally feasible within an operating band.
As part of the CLI WI, RAN4 has been tasked to investigate the adjacent channel co-existence effects arising when CLI, or more generically dynamic TDD is operated in an aggressor network. The scope of the investigation is to target no or very minimal impact on RF requirements, and so the investigation examines the throughput losses experienced in a victim network assuming that all base stations and UEs conform to the release 15 requirements.
This report captures a description of the adjacent channel interference effects that arise with dynamic TDD as well as a simulation investigation of adjacent channel interference in a number of different deployment scenarios.
full Table of Contents for TR 38.828 Word version: 16.0.0