Technologies for NR coverage enhancement
Methods to enhance the coverage of NR systems for coverage-limited wireless devices are disclosed. A serving base station may configure a coverage-limited UE with parameters for the UE to operate in a coverage enhancement mode through RRC signaling, DCI, or RAR grant. The UE may use the configuration parameters to determine whether to enter into the coverage enhancement mode when connecting and communicating with the serving base station. The configuration parameters may configure the UE to exploit both time diversity and frequency diversity to extend and enhance coverage when receiving PDSCH and PDCCH channels. The UE may use the configuration parameters to receive PDSCH and PCCCH that are coverage enhanced using time repetitions and frequency hopping. Advantageously, the base station may flexibly and dynamically configure the UE with coverage enhancement parameters to extend the coverage of the UE using time diversity and frequency diversity gains as the UE moves around.
1. A method of communicating by a wireless device, the method comprising:
receiving, by the wireless device from a base station of a wireless communication network, configuration information used to extend a communication range of the wireless device when communicating with the base station, the configuration information including time repetition parameters and frequency hopping parameters used for downlink receptions by the wireless device, wherein the time repetition parameters and frequency hopping parameters comprise a number of time repetitions for each frequency hop; and
receiving, by the wireless device from the base station, downlink receptions that are repeated in time with a frequency hopping pattern based on the time repetition parameters and the frequency hopping parameters in the configuration information.
2. The method of claim 1 , wherein the time repetition parameters and frequency hopping parameters further comprise:
a total number of time repetitions; and
a frequency hopping step pattern.
3. The method of claim 2 , wherein the downlink receptions that are repeated in time with the frequency hopping pattern comprise data or control channel that are repeated using resources comprising:
time domain resources starting from a starting slot and consecutively incrementing a slot number for the total number of time repetitions; and
frequency domain resources including a first frequency hop resource, a second frequency hop resource at the first frequency hop resource plus a frequency offset, and additional frequency hop resources at the first frequency hop resource plus additional iterations of the frequency offset to complete the frequency hopping pattern, wherein each of the frequency hop resources is repeated in the time domain for the number of time repetitions for each frequency hop.
4. The method of claim 3 , wherein the resources used for the downlink receptions that are repeated in time with the frequency hopping pattern are preempted by resources used for transmitting system information by the base station.
5. The method of claim 2 , wherein the frequency hopping pattern is a function of a number of frequency domain resources assigned to the wireless device.
6. The method of claim 2 , wherein the frequency hopping step pattern comprises two frequency hopping step patterns, and wherein the method further comprises:
receiving, by the wireless device, a downlink bandwidth part (DL BWP) threshold from the base station; and
comparing a number of DL BWP resource blocks allocated to the wireless device against the DL BWP threshold to select one of the two frequency hopping step patterns for receiving the downlink receptions that are repeated in time with the frequency hopping pattern.
7. The method of claim 6 , wherein when the number of DL resource blocks allocated is less than the DL BWP threshold, one of the two frequency hopping step patterns with a lower number of steps is selected.
8. The method of claim 1 , wherein the frequency hopping step pattern comprises two frequency hopping step patterns, and wherein the method further comprises:
receiving, by the wireless device from the base station, a signaling to select one of the two frequency hopping step patterns for receiving the downlink receptions that are repeated in time with the frequency hopping pattern.
9. The method of claim 1 , further comprising:
receiving, by the wireless device, a reference signal threshold from the base station;
measuring, by the wireless device, a reference signal transmitted by the base station;
comparing the measured reference signal against the reference signal threshold to determine whether to enter a mode to extend the communication range of the wireless device; and
communicating to the base station that the wireless device enters into the mode to extend the communication range of the wireless device in response to the comparing.
10. A wireless device, comprising:
at least one radio, wherein the at least one radio is configured to communicate with a base station of a wireless communication network using at least one antenna; and
at least one processor coupled to the at least one radio, wherein the at least one processor is configured to:
receive from the base station configuration information used to extend a communication range of the wireless device when the wireless device communicates with the base station, the configuration information including time repetition parameters and frequency hopping parameters used for downlink receptions by the wireless device, wherein the time repetition parameters and frequency hopping parameters comprise a number of time repetitions for each frequency hop; and
receive from the base station downlink receptions that are repeated in time with a frequency hopping pattern based on the time repetition parameters and the frequency hopping parameters in the configuration information.
11. The wireless device of claim 10 , wherein the time repetition parameters and frequency hopping parameters further comprise:
a total number of time repetitions; and
a frequency hopping step pattern.
12. The wireless device of claim 11 , wherein the downlink receptions that are repeated in time with the frequency hopping pattern comprise data or control channel that are repeated using resources comprising:
time domain resources starting from a starting slot and consecutively incrementing a slot number for the total number of time repetitions; and
frequency domain resources including a first frequency hop resource, a second frequency hop resource at the first frequency hop resources plus a frequency offset, and additional frequency hop resource at the first frequency hop resource plus additional iterations of the frequency offset to complete the frequency hopping pattern, wherein each of the frequency hop resources is repeated in the time domain for the number of time repetitions for each frequency hop.
13. The wireless device of claim 12 , wherein the resources used for the downlink receptions that are repeated in time with the frequency hopping pattern are preempted by resources used for transmitting system information by the base station.
14. The wireless device of claim 11 , wherein the frequency hopping pattern is a function of a number of frequency domain resources assigned to the wireless device.
15. The wireless device of claim 11 , wherein the frequency hopping step pattern comprises two frequency hopping step patterns, and wherein the at least one processor is further configured to:
receive from the base station a downlink bandwidth part (DL BWP) threshold; and
compare a number of DL BWP resource blocks allocated to the wireless device against the DL BWP threshold to select one of the two frequency hopping step patterns to receive the downlink receptions that are repeated in time with the frequency hopping pattern.
16. The wireless device of claim 15 , wherein when the number of DL resource blocks allocated is less than the DL BWP threshold, one of the two frequency hopping step patterns with a lower number of steps is selected.
17. The wireless device of claim 11 , wherein the frequency hopping step pattern comprises two frequency hopping step patterns, and wherein the at least one processor is further configured to:
receive from the base station a signaling to select one of the two frequency hopping step patterns to receive the downlink receptions that are repeated in time with the frequency hopping pattern.
18. The wireless device of claim 10 , wherein the at least one processor is further configured to:
receive a reference signal threshold from the base station;
measure a reference signal transmitted by the base station;
compare the measured reference signal against the reference signal threshold to determine whether to enter a mode to extend the communication range of the wireless device; and
communicate to the base station that the wireless device enters into the mode to extend the communication range of the wireless device in response to the compare.
19. A method of communicating by a base station of a wireless communication network, the method comprising:
transmitting, by the base station to a wireless device of the communication network, configuration information used to extend a communication range of between the base station and the wireless device, the configuration information including time repetition parameters and frequency hopping parameters used for downlink transmissions and uplink receptions by the base station, wherein the time repetition parameters and frequency hopping parameters comprise a number of time repetitions for each frequency hop; and
transmitting, by the base station to the wireless device, downlink receptions that are repeated in time with a frequency hopping pattern based on the time repetition parameters and the frequency hopping parameters in the configuration information.
20. The method of claim 19 , wherein the time repetition parameters and frequency hopping parameters further comprise:
a total number of time repetitions; and
a frequency hopping step pattern.