SRS Periodicity Determination Aided by Time-Domain Channel Property

In TDD MIMO system, SRS is typically used to acquire DL CSI. The SRS periodicity is a key factor impacting the system performance in mobile scenarios. A shorter SRS periodicity facilitates more frequent CSI updating and better adaptability to channel variation, but also causes higher RS overhead. In this paper, we propose to use TDCP, which reflects the channel variation rate and is measured and reported by UE, to determine the SRS periodicity. Possible reporting formats of TDCP are discussed and evaluated. LLS results show that, DL throughput can be significantly improved with the aiding of TDCP, and a reporting format of TDCP including multiple amplitudes and phases of time-domain channel correlations provides best performance and flexibility.