  New radio technologies for the fifth generation of wireless system have been
extensively studied globally. Specifically, air interface protocols for 5G
radio access network will be standardized in coming years by 3GPP. Due to its
crucial function in scheduled system, physical layer downlink control channel
(PDCCH) is a core element to enable all physical layer data transmissions.
Recently, configurable distributed PDCCH with the intention to cope with
different scenarios has been developed in 3GPP. To have comprehensive
understanding of respective technical advantages and potential scenario
dependent limitations, detailed performance analysis and evaluations of
configurable distributed PDCCH are thoroughly studied in this paper. In
particular, exponential effective SNR mapping (EESM) has been employed as the
performance metric of configurable distributed PDCCH in different scenarios. It
is demonstrated from EESM results that configurable distributed PDCCH offers
additional degree of freedom for the trade-off between achieved frequency
diversity and channel estimation gain by adjusting resource bundling level
according to the channel and interference scenario experienced by the control
channel transmission.
