Random access channel (RACH) coverage enhancement

1. A method of random access channel (RACH) procedure at a user equipment (UE), comprising the steps of:

transmitting a first message including a random preamble selected from a set of preambles to a base station (BS);

receiving a second message including control information required for establishing communication between the UE and the BS in one or more physical downlink control channels (PDCCHs) in a first time duration;

determining one PDCCH in the one or more PDCCHs which has the highest received signal power (RSRP);

in a third message reporting the one PDCCH with the highest RSRP to the base station and transmitting uplink scheduling information in one or more physical uplink shared channels (PUSCHs) in a second time duration; and

receiving a fourth message, the fourth message includes a contention resolution process and a report indicating the one PUSCH with the highest RSRP.

2. The method of claim 1 , wherein each physical downlink control channel (PDCCH) in the one or more PDCCHs is received with a different beam.

3. The method of claim 1 , wherein the one or more physical downlink control channels (PDCCHs) are repetitions of a particular PDCCH.

4. The method of claim 2 , further comprising:

determining one physical downlink control channel (PDCCH) in the one or more PDCCHs with a best beam steered towards the user equipment (UE); and

reporting the one PDCCH with the best beam to the base station (BS) in the third message.

5. The method of claim 1 , wherein:

the first time duration includes one or more time slots; and

the physical downlink control channels (PDCCHs) are received in same Control Resource Set (CORSET) in the one or more time slots.

6. The method of claim 1 , wherein:

the first time duration includes one or more time slots;

the physical downlink control channel (PDCCHs) are received in different Control Resource Set (CORSET)[in the one or more time slots.

7. A user equipment (UE), comprising:

a transceiver configured to:

transmit a first message including a random preamble selected from a set of preambles to a base station (BS);

receive a second message including control information required for establishing communication between the UE and the BS in one or more physical downlink control channels (PDCCHs) in a first time duration;

determine one PDCCH in the one or more PDCCHs which has the highest received signal power (RSRP);

report the one PDCCH with the highest RSRP to the BS in a third message;

transmit uplink scheduling information in one or more physical uplink shared channels (PUSCHs) in the third message in a second time duration; and

receive a fourth message, the fourth message includes a contention resolution process and a report indicating the one PUSCH with the highest RSRP.

8. The user equipment (UE) of claim 7 , wherein the transceiver is further configured to receive each physical downlink control channel (PDCCH) in the one or more PDCCHs with a different beam.

9. The user equipment of claim 7 , wherein the one or more physical downlink control channels (PDCCHs) are repetitions of a particular PDCCH.

10. The user equipment (UE) of claim 8 , wherein the transceiver is further configured to:

determine one physical downlink control channel (PDCCH) in the one or more PDCCHs with a best beam steered towards the UE; and

report the one PDCCH with the best beam to the base station (BS) in the third message.

11. The user equipment (UE) of claim 7 , wherein

the first time duration includes one or more time slots; and

the transceiver is further configured to:

receive the physical downlink control channels (PDCCHs) in the Control Resource Set (CORSET) in the one or more time slots.

12. The user equipment (UE) of claim 7 , wherein:

the first time duration includes one or more time slots; and

the transceiver is further configured to:

receive the physical downlink control channels (PDCCHs) in different Control Resource Set (CORSET) in the one or more time slots.

13. A base station (BS), comprising:

a transceiver configured to:

receive a first message including a random preamble selected from a set of preambles from a user equipment (UE);

transmit a second message including control information required for establishing communication between the user equipment (UE) and the BS in one or more physical downlink control channels (PDCCHs) in a first time duration;

receive a third message, from the UE, reporting one PDCCH with a highest received signal power (RSRP);

receive uplink scheduling information, from the UE, in one or more physical uplink shared channels (PUSCHs) in the third message in a second time duration;

determine one PUSCH of the one or more PUSCHs with the highest RSRP;

report the one PUSCH with the highest RSRP to the UE in the third message; and

transmit a fourth message, the fourth message includes a contention resolution process and a report indicating the one PUSCH with the highest RSRP.

14. The base station (BS) of claim 13 , wherein the transceiver is further configured to transmit each physical downlink control channel (PDCCH) in the one or more PDCCHs with a different beam.

15. The base station (BS) of claim 13 , wherein the one or more physical downlink control channels (PDCCHs) are repetitions of a particular PDCCH.

16. The base station (BS) of claim 14 , wherein the transceiver is further configured to:

receive the one physical downlink control channel (PDCCH) with a best beam steered towards to the user equipment (UE) in the third message.

17. The base station (BS) of claim 13 , wherein

a first time duration includes one or more time slots; and

the transceiver is further configured to:

transmit the physical downlink control channel (PDCCH) in the Control Resource Set (CORSET in the one or more time slots.

18. The base station (BS) of claim 13 , wherein:

the first time duration includes one or more time slots; and

the transceiver is further configured to:

transmit the physical downlink control channel (PDCCH) in different Control Resource Set (CORSET) in the one or more time slots.

19. A system, comprising one or more processors and one or more non-transitory computer-readable media storing computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to perform operations, the operations comprising:

transmitting, to a base station (BS), a first message including a random preamble selected from a set of preambles;

receiving, at a user equipment (UE), a second message including control information required for establishing communication between the UE and the BS in one or more physical downlink control channels (PDCCHs) in a first time duration;

determining one PDCCH in the one or more PDCCHs which has a highest received signal power (RSRP);

reporting, to the BS, the one PDCCH with the highest RSRP in a third message;

transmitting, to the BS, uplink scheduling information in one or more physical uplink shared channels (PUSCHs) in the third message in a second time duration; and

receive a fourth message, from the BS, the fourth message including a contention resolution process and a report indicating the one PUSCH with the highest RSRP.

20. The system of claim 19 , wherein each physical downlink control channel (PDCCH) in the one or more PDCCHs is received with a different beam.