5G NR PDCCH: Design and Performance

This paper analyzes physical downlink control channel (PDCCH) for 5G New Radio (NR) technology defined as part of Rel-15 3GPP physical layer specifications. The particular combination of design elements makes NR PDCCH unique compared to the PDCCH or EPDCCH designs in LTE. We focus on the physical aspects of NR PDCCH structure and provide an in-depth summary of the design considerations, analysis of novel search space (SS) design options to better balance the PDCCH blind decoding (BD) and channel estimation capabilities, and performance evaluation of various transmission schemes and configurations supported by NR PDCCH. This study attests the flexibility and robustness of NR PDCCH design in addition to potential further enhancements for the scenarios with more stringent reliability requirements, e.g., URLLC applications.