Multiple access for users with different modes in a common uplink burst in a time division duplex subframe structure
Various aspects of the present disclosure provide for methods, apparatus, and computer software for multiple access to a channel carrying a common uplink burst transmitted by users that utilize two different modes. Specifically, a coupled mode provides for range extension for users at a cell edge, while a decoupled mode provides for user data transmissions within the common uplink burst. Multiple access between these different modes may be provided in a non-orthogonal scheme by moderating the amount of interference between the respective modes. Further, multiple access between these different modes may be provided in an orthogonal scheme by utilizing interleaved frequency division multiple access (IFDMA).
1. A method operable at a scheduling entity for wireless communication over a time division duplex (TDD) carrier, the method comprising:
receiving a first uplink burst from a coupled mode user within each of a downlink-centric subframe and an uplink-centric subframe of a frame on the TDD carrier, wherein the first uplink burst of the coupled mode user comprises a sounding reference signal (SRS) and data configured to be demodulated using the SRS as a demodulation reference signal (DM-RS); and
receiving, simultaneously with the first uplink burst, a second uplink burst from a decoupled mode user within each of the downlink-centric subframe and the uplink-centric subframe of the frame on the TDD carrier, wherein the second uplink burst of the decoupled mode user comprises separate SRS and DM-RS; and
differentiating the first uplink burst from the coupled mode user from the second uplink burst from the decoupled mode user on the TDD carrier, utilizing non-orthogonal multiple access.
2. The method of claim 1 , wherein the differentiating comprises:
storing the received first uplink burst and second uplink burst in memory;
decoding the second uplink burst from the decoupled mode user;
applying interference cancellation to remove the second uplink burst from the stored received bursts; and
decoding the first uplink burst from the coupled mode user from the interference cancelled received uplink bursts.
3. The method of claim 1 , further comprising:
transmitting a control message to at least one of the decoupled mode user or the coupled mode user, the control message configured to control a contribution of the first uplink burst and/or the second uplink burst to a rise over thermal (RoT) detected by the scheduling entity such that the detected RoT does not exceed a predetermined threshold.
4. The method of claim 3 , wherein the control message comprises an indication of a modulation and coding scheme (MCS) to be utilized by the decoupled mode user.
5. The method of claim 3 , wherein the control message comprises a power control command for setting a power of the second uplink burst from the decoupled mode user.
6. The method of claim 3 , wherein the control message comprises a power control command for setting a power of the first uplink burst from the coupled mode user.
7. A method operable at a scheduling entity for wireless communication over a time division duplex (TDD) carrier, the method comprising:
receiving a first uplink burst from a coupled mode user within each of a downlink-centric subframe and an uplink-centric subframe of a frame on the TDD carrier, wherein the first uplink burst of the coupled mode user comprises a sounding reference signal (SRS) and data configured to be demodulated using the SRS as a demodulation reference signal (DM-RS); and
receiving, simultaneously with the first uplink burst, a second uplink burst from a decoupled mode user within each of the downlink-centric subframe and the uplink-centric subframe of the frame on the TDD carrier, wherein the second uplink burst of the decoupled mode user comprises separate SRS and DM-RS; and
differentiating the first uplink burst from the coupled mode user from the second uplink burst from the decoupled mode user on the TDD carrier, utilizing orthogonal multiple access.
8. The method of claim 7 , wherein the first uplink burst from the coupled mode user comprises at least one symbol comprising uplink control information, the uplink control information being structured as a single carrier waveform using interleaved frequency division multiple access (IFDMA) occupying a subset of subcarriers across resource blocks in the TDD carrier.
9. The method of claim 8 , wherein the second uplink burst from the decoupled mode user comprises at least one symbol comprising uplink control information, the uplink control information being structured as an orthogonal frequency division multiplexed (OFDM) waveform interleaved between at least a portion of the subcarriers making up the uplink control information corresponding to the first uplink burst from the coupled mode user.
10. A scheduling entity configured for wireless communication over a time division duplex (TDD) carrier, the scheduling entity comprising:
a processor;
a memory communicatively coupled to the processor; and
a transceiver communicatively coupled to the processor,
wherein the processor and the memory are configured to:
receive a first uplink burst from a coupled mode user within each of a downlink-centric subframe and an uplink-centric subframe of a frame on the TDD carrier, wherein the first uplink burst of the coupled mode user comprises a sounding reference signal (SRS) and data configured to be demodulated using the SRS as a demodulation reference signal (DM-RS); and
receive, simultaneously with the first uplink burst, a second uplink burst from a decoupled mode user within each of the downlink-centric subframe and the uplink-centric subframe of the frame on the TDD carrier, wherein the second uplink burst of the decoupled mode user comprises separate SRS and DM-RS; and
differentiate the first uplink burst from the coupled mode user from the second uplink burst from the decoupled mode user on the TDD carrier, utilizing non-orthogonal multiple access.
11. The scheduling entity of claim 10 , wherein the processor and the memory are further configured to:
store the received first uplink burst and second uplink burst in the memory;
decode the second uplink burst from the decoupled mode user;
apply interference cancellation to remove the second uplink burst from the stored received bursts; and
decode the first uplink burst from the coupled mode user from the interference cancelled received uplink bursts.
12. The scheduling entity of claim 10 , wherein the processor and the memory are further configured to:
transmit a control message to at least one of the decoupled mode user or the coupled mode user, the control message configured to control a contribution of the first uplink burst and/or the second uplink burst to a rise over thermal (RoT) detected by the scheduling entity such that the detected RoT does not exceed a predetermined threshold.
13. The scheduling entity of claim 12 , wherein the control message comprises an indication of a modulation and coding scheme (MCS) to be utilized by the decoupled mode user.
14. The scheduling entity of claim 12 , wherein the control message comprises a power control command for setting a power of the second uplink burst from the decoupled mode user.
15. The scheduling entity of claim 12 , wherein the control message comprises a power control command for setting a power of the first uplink burst from the coupled mode user.
16. A scheduling entity configured for wireless communication over a time division duplex (TDD) carrier, the scheduling entity comprising:
a processor;
a memory communicatively coupled to the processor; and
a transceiver communicatively coupled to the processor,
wherein the processor and the memory are configured to:
receive a first uplink burst from a coupled mode user within each of a downlink-centric subframe and an uplink-centric subframe of a frame on the TDD carrier, wherein the first uplink burst of the coupled mode user comprises a sounding reference signal (SRS) and data configured to be demodulated using the SRS as a demodulation reference signal (DM-RS); and
receive, simultaneously with the first uplink burst, a second uplink burst from a decoupled mode user within each of the downlink-centric subframe and the uplink-centric subframe of the frame on the TDD carrier, wherein the second uplink burst of the decoupled mode user comprises separate SRS and DM-RS; and
differentiate the first uplink burst from the coupled mode user from the second uplink burst from the decoupled mode user on the TDD carrier, utilizing orthogonal multiple access.
17. The scheduling entity of claim 16 , wherein the first uplink burst from the coupled mode user comprises at least one symbol comprising uplink control information, the uplink control information being structured as a single carrier waveform using interleaved frequency division multiple access (IFDMA) occupying a subset of subcarriers across resource blocks in the TDD carrier.
18. The scheduling entity of claim 17 , wherein the second uplink burst from the decoupled mode user comprises at least one symbol comprising uplink control information, the uplink control information being structured as an orthogonal frequency division multiplexed (OFDM) waveform interleaved between at least a portion of the subcarriers making up the uplink control information corresponding to the first uplink burst from the coupled mode user.