Mixed numerology OFDM design
Methods, systems, and devices are described for hierarchical communications and low latency support within a wireless communications system. An eNB and/or a UE may be configured to operate within the wireless communications system which is at least partially defined through a first layer with first layer transmissions having a first subframe type and a second layer with second layer transmissions having a second subframe type. The first subframe type may have a first round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, and the second layer may have a second RTT that is less than the first RTT. Subframes of the first subframe type may be multiplexed with subframes of the second subframe type, such as through time division multiplexing. In some examples symbols of different duration may be multiplexed such that they different symbol durations coexist.
1. A method of wireless communication, comprising:
configuring a single frame structure of a single carrier with a first region having a first symbol duration and a second region having a second symbol duration different from the first symbol duration, wherein the first and second regions of the single frame structure of the single carrier are time-division multiplexed (TDM) or frequency-division multiplexed (FDM), wherein the first region includes a control channel and a shared channel, and the second region includes a control channel and a shared channel, and wherein the second region includes both downlink symbols and uplink symbols, and wherein the second symbol duration is configurable; and
communicating with a user equipment (UE) using the first or second region of the single frame structure of the single carrier.
2. The method of claim 1 , further comprising:
adjusting a portion of the single frame structure of the single carrier occupied by the second region based at least in part on a latency requirement of the UE.
3. The method of claim 2 , wherein the first and second regions are TDM, and wherein adjusting the portion of the single frame structure of the single carrier occupied by the second region comprises:
adjusting a time duration or periodicity of the second region.
4. The method of claim 2 , wherein the first and second regions are FDM, and wherein adjusting the portion of the single frame structure of the single carrier occupied by the second region comprises:
adjusting a bandwidth of the second region.
5. The method of claim 4 , further comprising:
configuring a guard band between the first and second regions.
6. The method of claim 1 , wherein configuring the single frame structure of the single carrier comprises:
transmitting a signal in a symbol of the first region, the signal indicative of the second symbol duration and comprising at least one of radio resource control (RRC) signaling, a broadcast message, Layer 1 signaling, or a media access control (MAC) layer signaling.
7. The method of claim 1 , further comprising:
configuring a third region of the single frame structure of the single carrier, the third region having the second symbol duration, wherein the first and second regions are FDM, and wherein the third region is TDM with the first and second regions.
8. The method of claim 7 , further comprising:
configuring a guard band between the first and second regions.
9. The method of claim 1 , wherein the second symbol duration is shorter than the first symbol duration.
10. The method of claim 1 , wherein the shared channel of the first region comprises a first physical downlink shared channel (PDSCH), and the control channel of the first region comprises a first physical downlink control channel (PDCCH); and
wherein the shared channel of the second region comprises a second physical downlink shared channel (PDSCH), and the control channel of the second region comprises a second physical downlink control channel (PDCCH).
11. The method of claim 1 , wherein the first region has a first bandwidth and wherein the second region has a second bandwidth different from the first bandwidth.
12. A method of wireless communication, comprising:
identifying a first region of a single frame structure of a single carrier, the first region having a first symbol duration;
identifying a second region of the single frame structure of the single carrier, the second region having a second symbol duration different from the first symbol duration, wherein the first and second regions of the single frame structure of the single carrier are time-division multiplexed (TDM) or frequency-division multiplexed (FDM), wherein the first region includes a control channel and a shared channel, and the second region includes a control channel and a shared channel, and wherein the second region includes both downlink symbols and uplink symbols, and wherein the second symbol duration is configurable; and
communicating with a base station using the first or second region of the single frame structure of the single carrier.
13. The method of claim 12 , wherein the first and second regions are FDM, and wherein the method further comprises:
identifying a guard band between the first and second regions.
14. The method of claim 12 , wherein identifying the second region of the single frame structure of the single carrier comprises:
receiving a signal in a symbol of the first region, the signal indicative of the second symbol duration and comprising at least one of radio resource control (RRC) signaling, a broadcast message, Layer 1 signaling, or a media access control (MAC) layer signaling.
15. The method of claim 12 , further comprising:
identifying a third region of the single frame structure of the single carrier, the third region having the second symbol duration, wherein the first and second regions are FDM and wherein the third region is TDM with the first and second regions.
16. The method of claim 15 , further comprising:
identifying a guard band between the first and second regions.
17. The method of claim 12 , wherein the second symbol duration is shorter than the first symbol duration.
18. The method of claim 12 , wherein the first region has a 15 kHz subcarrier spacing, and the second region has a 60 kHz or 120 kHz subcarrier spacing.
19. The method of claim 12 , wherein the first region is a first subframe of the single frame structure, and the second region is a second subframe of the single frame structure that is different than the first subframe;
wherein the first subframe comprises a first number of orthogonal frequency division multiplexing (OFDM) symbols, and the second subframe comprises a second number of OFDM symbols that is different from the first number of OFDM symbols; and
wherein each of the OFDM symbols in the first subframe have the first symbol duration, and each of the OFDM symbols in the second subframe have the second symbol duration that is different than the first symbol duration.
20. The method of claim 12 , wherein the first region has a first bandwidth and wherein the second region has a second bandwidth different from the first bandwidth.
21. An apparatus for wireless communication, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory, the instructions executable by the processor to cause the apparatus to:
configure a single frame structure of a single carrier with a first region having a first symbol duration and a second region having a second symbol duration different from the first symbol duration, wherein the first and second regions of the single frame structure of the single carrier are time-division multiplexed (TDM) or frequency-division multiplexed (FDM), wherein the first region includes a control channel and a shared channel, and the second region includes a control channel and a shared channel, and wherein the second region includes both downlink symbols and uplink symbols, and wherein the second symbol duration is configurable; and
communicate with a user equipment (UE) using the first or second region of the single frame structure of the single carrier.
22. The apparatus of claim 21 , wherein the instructions are executable by the processor to cause the apparatus to:
adjust a portion of the single frame structure of the single carrier occupied by the second region based at least in part on a latency requirement of the UE.
23. The apparatus of claim 22 , wherein the first and second regions are TDM, and wherein the instructions are executable by the processor to cause the apparatus to:
adjust a time duration or periodicity of the second region.
24. The apparatus of claim 22 , wherein the first and second regions are FDM, and wherein the instructions are executable by the processor to cause the apparatus to:
adjust a bandwidth of the second region.
25. The apparatus of claim 24 , wherein the instructions are executable by the processor to cause the apparatus to:
configure a guard band between the first and second regions.
26. The apparatus of claim 21 , wherein the instructions are executable by the processor to cause the apparatus to:
transmit a signal in a symbol of the first region, the signal indicative of the second symbol duration and comprising at least one of radio resource control (RRC) signaling, a broadcast message, Layer 1 signaling, or a media access control (MAC) layer signaling.
27. The apparatus of claim 21 , wherein the instructions are executable by the processor to cause the apparatus to:
configure a third region of the single frame structure of the single carrier, the third region having the second symbol duration, wherein the first and second regions are FDM, and wherein the third region is TDM with the first and second regions.
28. The apparatus of claim 27 , wherein the instructions are executable by the processor to cause the apparatus to:
configure a guard band between the first and second regions.
29. The apparatus of claim 21 , wherein the second symbol duration is shorter than the first symbol duration.
30. An apparatus for wireless communication, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory, the instructions executable by the processor to cause the apparatus to:
identify a first region of a single frame structure of a single carrier, the first region having a first symbol duration;
identify a second region of the single frame structure of the single carrier, the second region having a second symbol duration different from the first symbol duration, wherein the first and second regions of the single frame structure of the single carrier are time-division multiplexed (TDM) or frequency-division multiplexed (FDM), wherein the first region includes a control channel and a shared channel, and the second region includes a control channel and a shared channel, and wherein the second region includes both downlink symbols and uplink symbols, and wherein the second symbol duration is configurable; and
communicate with a base station using the first or second region of the single frame structure of the single carrier.
31. The apparatus of claim 30 , wherein the first and second regions are FDM, and wherein the instructions are executable by the processor to cause the apparatus to:
identify a guard band between the first and second regions.
32. The apparatus of claim 30 , wherein the instructions are executable by the processor to cause the apparatus to:
receive a signal in a symbol of the first region, the signal indicative of the second symbol duration and comprising at least one of radio resource control (RRC) signaling, a broadcast message, Layer 1 signaling, or a media access control (MAC) layer signaling.
33. The apparatus of claim 30 , wherein the instructions are executable by the processor to cause the apparatus to:
identify a third region of the single frame structure of the single carrier, the third region having the second symbol duration, wherein the first and second regions are FDM and wherein the third region is TDM with the first and second regions.
34. The apparatus of claim 33 , wherein the instructions are executable by the processor to cause the apparatus to:
identify a guard band between the first and second regions.
35. The apparatus of claim 30 , wherein the second symbol duration is shorter than the first symbol duration.