Narrowband frequency hopping mechanisms to overcome bandwidth restrictions in the unlicensed frequency spectrum
In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. In one example, the apparatus may be a base station. In certain configurations, the apparatus may transmit information indicating a narrowband frequency hopping pattern to at least one UE. In certain aspects, the narrowband frequency hopping pattern may correspond to a plurality of frames. In certain other aspects, the plurality of frames may include at least one non-anchor channel and being associated with a plurality of anchor channels. The apparatus may communicate with the at least one UE using the narrowband frequency hopping pattern, including concurrently transmitting a discovery reference signal (DRS) in each of the plurality of anchor channels at a start of each hopping frame. In certain aspects, communication on the plurality of anchor channels may occur during the same frames.
1. A method of wireless communication of a base station, comprising:
transmitting information indicating a narrowband frequency hopping pattern to at least one user equipment (UE), the narrowband frequency hopping pattern corresponding to a plurality of frames, the plurality of frames including at least one non-anchor channel and being associated with a plurality of anchor channels; and
communicating with the at least one UE using the narrowband frequency hopping pattern including concurrently transmitting a discovery reference signal (DRS) in each of the plurality of anchor channels at a start of each hopping frame, wherein communication on the plurality of anchor channels occurs during the same frames, and wherein each DRS includes at least a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) for a respective anchor channel.
2. The method of claim 1 , wherein each DRS further includes a physical broadcast channel (PBCH) and a system information block (SIB).
3. The method of claim 1 , wherein each anchor channel carries information indicating a hopping pattern on the at least one non-anchor channel for a corresponding anchor channel from the plurality of anchor channels.
4. The method of claim 1 , wherein a single non-anchor channel is associated with the plurality of anchor channels.
5. The method of claim 1 , wherein:
the at least one non-anchor channel in each of the plurality of frames includes M non-anchor channels within a wideband;
the M non-anchor channels are grouped into M carriers across the plurality of frames; and
each of the M carriers occupying a set of adjacent non-anchor channels in each of the plurality of frames.
6. The method of claim 5 , wherein the communicating with the at least one UE using the narrowband frequency hopping pattern further comprises:
transmitting a plurality of downlink transmissions to one or more UEs, the plurality of downlink transmissions being transmitted concurrently in the M carriers.
7. The method of claim 6 , wherein:
the one or more UEs include a single UE; and
the plurality of downlink transmissions include an initial downlink transmission transmitted on one of the M carriers and downlink retransmissions transmitted on a subset of the M carriers.
8. The method of claim 6 , wherein the plurality of downlink transmissions includes a reservation signal on each of the M carriers when a data transmission is unavailable.
9. The method of claim 6 , wherein the communicating with the at least one UE using the narrowband frequency hopping pattern further comprises:
receiving a plurality of uplink transmissions from the one or more UEs, the plurality of uplink transmissions being received concurrently in the M carriers.
10. The method of claim 9 , wherein:
a first portion of each of the M carriers is allocated for downlink transmissions and a second portion of each of the M carriers is allocated for uplink transmissions; and
the second portion is located subsequent to the first portion in a time domain.
11. The method of claim 5 , wherein:
each of the M carriers is associated with a respective hopping sequence across the plurality of frames; and
each respective hopping sequence includes a respective fixed offset from contiguous non-anchor channels in the M carrier.
12. The method of claim 11 , wherein each respective hopping sequence comprises a pseudo-random hopping sequence.
13. The method of claim 5 , wherein each of the M carriers have a same frame structure.
14. The method of claim 5 , wherein a total bandwidth of each of the M carriers meets a bandwidth threshold criteria.
15. The method of claim 5 , wherein the communicating with the at least one UE using the narrowband frequency hopping pattern comprises:
concurrently transmitting a first downlink transmission to a first UE in a first portion of each of the M carriers; and
concurrently transmitting a second downlink transmission to a second UE in a second portion of each of the M carriers, the second portion being subsequent to the first portion in a time domain.
16. The method of claim 15 , wherein the communicating with the at least one UE using the narrowband frequency hopping pattern further comprises:
receiving a first uplink transmission in a third portion of a first carrier of the M carriers; and
receiving a second uplink transmission in the third portion of a second carrier of the M carriers, the first uplink transmission and the second uplink transmission being received concurrently, and the third portion being adjacent to the second portion in the time domain.
17. A method of wireless communication of a user equipment (UE), comprising:
receiving information indicating a narrowband frequency hopping pattern from a base station, the narrowband frequency hopping pattern corresponding to a plurality of frames, the plurality of frames including at least one non-anchor channel and being associated with a plurality of anchor channels; and
communicating with the base station using the narrowband frequency hopping pattern including receiving concurrent transmissions of a discovery reference signal (DRS) in each of the plurality of anchor channels at a start of each hopping frame, wherein communication on the plurality of anchor channels occurs during the same frames, and wherein each DRS includes at least a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) for a respective anchor channel.
18. The method of claim 17 , wherein each DRS further includes a physical broadcast channel (PBCH) and a system information block (SIB).
19. The method of claim 17 , wherein each anchor channel carries information indicating a hopping pattern on the at least one non-anchor channel for a corresponding anchor channel from the plurality of anchor channels.
20. The method of claim 17 , wherein a single non-anchor channel is associated with the plurality of anchor channels.
21. The method of claim 17 , wherein:
the at least one non-anchor channel in each of the plurality of frames includes M non-anchor channels within a wideband;
the M non-anchor channels are grouped into M carriers across the plurality of frames; and
each of the M carriers occupying a set of adjacent non-anchor channels in each of the plurality of frames.
22. The method of claim 21 , wherein:
each of the M carriers is associated with a respective hopping sequence across the plurality of frames; and
each respective hopping sequence includes a respective fixed offset from contiguous non-anchor channels in the M carrier.
23. The method of claim 22 , wherein the respective hopping sequence comprises a pseudo-random hopping sequence.
24. An apparatus for wireless communication of a base station, comprising:
a memory; and
at least one processor coupled to the memory and configured to:
transmit information indicating a narrowband frequency hopping pattern to at least one user equipment (UE), the narrowband frequency hopping pattern corresponding to a plurality of frames, the plurality of frames including at least one non-anchor channel and being associated with a plurality of anchor channels; and
communicate with the at least one UE using the narrowband frequency hopping pattern including concurrently transmitting a discovery reference signal (DRS) in each of the plurality of anchor channels at a start of each hopping frame, wherein communication on the plurality of anchor channels occurs during the same frames, and wherein each DRS includes at least a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) for a respective anchor channel.
25. The apparatus of claim 24 , wherein each DRS further includes a physical broadcast channel (PBCH) and a system information block (SIB).
26. The apparatus of claim 24 , wherein each anchor channel carries information indicating a hopping pattern on the at least one non-anchor channel for a corresponding anchor channel from the plurality of anchor channels.
27. The apparatus of claim 24 , wherein a single non-anchor channel is associated with the plurality of anchor channels.
28. An apparatus for wireless communication of a user equipment (UE), comprising:
a memory; and
at least one processor coupled to the memory and configured to:
receive information indicating a narrowband frequency hopping pattern from a base station, the narrowband frequency hopping pattern corresponding to a plurality of frames, the plurality of frames including at least one non-anchor channel and being associated with a plurality of anchor channels; and
communicate with the base station using the narrowband frequency hopping pattern including receiving concurrent transmissions of a discovery reference signal (DRS) in each of the plurality of anchor channels at a start of each hopping frame, wherein communication on the plurality of anchor channels occurs during the same frames, and wherein each DRS includes at least a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) for a respective anchor channel.
29. The apparatus of claim 28 , wherein each DRS further includes a physical broadcast channel (PBCH) and a system information block (SIB).
30. The apparatus of claim 28 , wherein a single non-anchor channel is associated with the plurality of anchor channels.