A Novel Pilot Design and Channel Estimation in 5G Multi-Numerology Systems

Multi-numerology systems are considered to be promising communication frameworks in 5G new radio (NR) due to their flexibility. However, inter-numerology interference (inter-NI) degrades the quality of communication systems. Hence, techniques for mitigating inter-NI are needed to support multiple numerologies. In particular, the effect of the inter-NI should be considered in channel estimation process. We propose a pilot design which requires relatively short training overhead and mitigates the inter-NI. We stress that inter-NI does not exist in most cases when the proposed pilot signal is used. With taking account of the special case where inter-NI exists, we develop the channel estimation algorithm based on inter-NI cancellation. In addition, we analyze the effect of inter-NI cancellation algorithm which not only eliminates interference but also reduces the variance of noise. The simulation results verify that the performance of channel estimation with the proposed pilot signal is better than the quality of estimation with the case where user equipments transmit their pilot signals in a time division manner.