Methods and devices for PDCCH monitoring

1. A method in a network device for configuration of Physical Downlink Control Channel, PDCCH, monitoring by a terminal device, the method comprising:

determining a PDCCH monitoring configuration indicating a PDCCH resource pool to be monitored by the terminal device at an aggregation level, the PDCCH monitoring configuration determined based on a received signal power at one of the terminal device and the network device and at least one of:

when the received signal power is lower than a first threshold power, a PDCCH resource pool for an aggregation level lower than a third threshold level is null; and

when the received signal power is higher than a second threshold power, a PDCCH resource pool for an aggregation level higher than a fourth threshold level is null; and

transmitting the PDCCH monitoring configuration to the terminal device.

2. The method of claim 1 , wherein the terminal device is configured with a PDCCH search space and the PDCCH resource pool for the aggregation level comprises less than all Control Channel Elements, CCEs, in the PDCCH search space.

3. The method of claim 2 , wherein the aggregation level is lower than or equal to a first threshold level.

4. The method of claim 3 , wherein the PDCCH monitoring configuration further indicates a PDCCH resource pool for an aggregation level higher than the first threshold level that comprises all CCEs in the PDCCH search space.

5. The method of claim 1 , wherein the PDCCH search space comprises at least one of a common PDCCH search space and a dedicated PDCCH search space.

6. The method of claim 1 , further comprising:

transmitting an instruction to enable or disable the PDCCH monitoring configuration to the terminal device via one of a Medium Access Control, MAC, Control Element, CE, and a PDCCH order.

7. A network device configured for configuration of Physical Downlink Control Channel, PDCCH, monitoring by a terminal device, the network device comprising a transceiver, a processor and a memory, the memory comprising instructions executable by the processor whereby the network device is configured to:

determine a PDCCH monitoring configuration indicating a PDCCH resource pool to be monitored by the terminal device at an aggregation level, the PDCCH monitoring configuration determined based on a received signal power at one of the terminal device and the network device and at least one of:

when the received signal power is lower than a first threshold power, a PDCCH resource pool for an aggregation level lower than a third threshold level is null; and

when the received signal power is higher than a second threshold power, a PDCCH resource pool for an aggregation level higher than a fourth threshold level is null; and

transmit the PDCCH monitoring configuration to the terminal device.

8. A method in a terminal device for Physical Downlink Control Channel, PDCCH, monitoring, comprising:

receiving from a network device a PDCCH monitoring configuration indicating a PDCCH resource pool to be monitored by the terminal device at an aggregation level; and

monitoring a PDCCH from the network device in accordance with the PDCCH monitoring configuration;

the PDCCH monitoring configuration dependent on a received signal power at the terminal device or the network device and at least one of:

when the received signal power is lower than a first threshold power, a PDCCH resource pool for an aggregation level lower than a third threshold level is null; and

when the received signal power is higher than a second threshold power, a PDCCH resource pool for an aggregation level higher than a fourth threshold level is null.

9. The method of claim 8 , wherein the terminal device is configured with a PDCCH search space and the PDCCH resource pool for the aggregation level comprises less than all Control Channel Elements, CCEs, in the PDCCH search space.

10. The method of claim 9 , wherein the aggregation level is lower than or equal to a first threshold level.

11. The method of claim 10 , wherein the PDCCH monitoring configuration further indicates a PDCCH resource pool for an aggregation level higher than the first threshold level that comprises all CCEs in the PDCCH search space.

12. The method of claim 8 , wherein the PDCCH search space comprises at least one of a common PDCCH search space and a dedicated PDCCH search space.

13. The method of claim 8 , further comprising:

receiving an instruction to enable or disable the PDCCH monitoring configuration from the network device via one of a Medium Access Control, MAC, Control Element, CE, and a PDCCH order.

14. A terminal device configured for Physical Downlink Control Channel, PDCCH, monitoring, the terminal device comprising a transceiver, a processor and a memory, the memory comprising instructions executable by the processor whereby the terminal device is configured to:

receive from a network device a PDCCH monitoring configuration indicating a PDCCH resource pool to be monitored by the terminal device at an aggregation level; and

monitor a PDCCH from the network device in accordance with the PDCCH monitoring configuration,

the PDCCH monitoring configuration dependent on a received signal power at the terminal device or the network device and at least one of:

when the received signal power is lower than a first threshold power, a PDCCH resource pool for an aggregation level lower than a third threshold level is null; and

when the received signal power is higher than a second threshold power, a PDCCH resource pool for an aggregation level higher than a fourth threshold level is null.