Physical downlink control channel design for NR systems
A new design for physical downlink control channel (PDCCH) is proposed for the next generation 5G new radio systems. A UE receives the configuration of a default control resource set (CORESET) in MIB/SIB from its serving base station. The default CORESET contains both common search space and UE-specific search space for candidate PDCCH transmission. A PDCCH in a default CORESET is mapped to physical resource in a distributed or localized manner. Specifically, various REG-to-CCE mapping rules are proposed to improve frequency diversity gain, or frequency selectivity gain, or to reduce latency of PDCCH processing. Further, to facilitate analog beamforming in mmWave systems, the default CORESET is transmitted in a synchronization signal (SS) block associated with a corresponding analog beam direction.
1. A method comprising:
receiving one or more synchronization signal blocks (SS Blocks) from a base station by a user equipment (UE), wherein each SS block is associated with a corresponding analog beam direction;
obtaining a default control resource set (CORESET) in an SS block and determining a corresponding UE-favored analog beam direction, wherein the default CORESET comprises a set of physical resource blocks (PRBs), a set of OFDM symbols, a numerology, a periodicity, and reference signal (RS) configuration;
obtaining a physical random-access channel (PRACH) resource associated with the default CORESET; and
performing an access procedure over the obtained PRACH resources; and
receiving an additional CORESET over a higher layer signaling after the UE obtains a UE ID from the base station.
2. The method of claim 1 , wherein the default CORESET contains both a common search space and a UE-specific search space for physical downlink control channel (PDCCH) transmission.
3. The method of claim 2 , wherein the UE receives a broadcast or multicast PDCCH transmitted in the default CORESET of all analog beam directions.
4. The method of claim 1 , wherein the UE receives a unicast PDCCH transmitted in the additional CORESET using the UE-favored analog beam direction.
5. The method of claim 1 , wherein each PDCCH is associated with a set of control channel elements (CCEs), and wherein the additional CORESET and the default CORESET contain an integer multiple number of CCEs in the frequency domain.
6. A user equipment (UE) comprising:
a radio frequency (RF) receiver that receives one or more synchronization signal blocks (SS Blocks) from a base station, wherein each SS block is associated with a corresponding analog beam direction;
a control circuit that obtains a default control resource set (CORESET) in an SS block and determining a corresponding UE-favored analog beam direction, wherein the default CORESET comprises a set of physical resource blocks (PRBs), a set of OFDM symbols, a numerology, a periodicity, and reference signal (RS) configuration; and
a channel access handling circuit that obtains a physical random-access channel (PRACH) resource associated with the default CORESET and performs an access procedure over the obtained PRACH resource, wherein the UE receives an additional CORESET over a higher layer signaling after the UE obtains a UE ID from the base station.
7. The UE of claim 6 , wherein the default CORESET contains both a common search space and a UE-specific search space for physical downlink control channel (PDCCH) transmission.
8. The UE of claim 7 , wherein the UE receives a broadcast or multicast PDCCH transmitted in the default CORESET of all analog beam directions.
9. The UE of claim 6 , wherein the UE receives a unicast PDCCH transmitted in the additional CORESET using the UE-favored analog beam direction.
10. The UE of claim 6 , wherein each PDCCH is associated with a set of control channel elements (CCEs), and wherein the additional CORESET and the default CORESET contain an integer multiple number of CCEs in the frequency domain.