System and method for interference cancellation using terminal cooperation
Soft information for achieving interference cancellation in downlink transmissions can be communicated over device-to-device (D2D) links, thereby allowing paired user equipments (UEs) to receive downlink transmissions over the same radio resources. More specifically, paired UEs that receive transmissions over the same time-frequency resources may exchange soft or hard information over D2D links in order to facilitate interference cancellation. The D2D links may be unidirectional or bidirectional, and may be established over in-band or out-of-band resources. Paired UEs may be in the same or different cells, and may receive their respective transmissions from the same or different transmit point. UEs may be paired with one another based on various criteria, e.g., interference cancellation capabilities, scheduling metrics, etc.
1. A method for interference cancellation in a wireless network, the method comprising:
receiving, by a first user equipment (UE), a signal carrying a first downlink transmission and a second downlink transmission, the first downlink transmission being communicated over the same radio resources as the second downlink transmission;
receiving, by the first UE, information corresponding to the second downlink transmission over a device to device (D2D) link after receiving the signal carrying the first downlink transmission, the D2D link extending between the first UE and a second UE; and
using the information received over the D2D link to decode the first downlink transmission in accordance with an interference cancellation technique.
2. The method of claim 1 , further using the information received over the D2D link to decode the first downlink transmission in accordance with an interference cancellation technique comprises:
performing, by the first UE, interference cancellation on the signal in accordance with the information related to the second downlink transmission; and
decoding, by the first UE, the first downlink transmission after performing interference cancellation on the signal.
3. The method of claim 1 , wherein the information related to the second downlink transmission comprises an encoded bit-stream carried by the second downlink transmission.
4. The method of claim 1 , wherein the information related to the second downlink transmission comprises soft information related to the second downlink transmission.
5. The method of claim 1 , wherein the information related to the second downlink transmission comprises parity information carried in the second downlink transmission.
6. The method of claim 1 , further comprising:
exchanging information related to the first downlink transmission and information related to the second downlink transmission over the D2D link until both the first downlink transmission and the second downlink transmission have been successfully decoded using the interference cancellation technique.
7. The method of claim 1 , wherein the first downlink transmission and the second downlink transmission originate from the same transmit point (TP).
8. The method of claim 1 , wherein the first downlink transmission and the second downlink transmission originate from different transmit points (TPs).
9. A method for interference cancellation in a wireless network, the method comprising:
receiving, by a first user equipment (UE), a signal carrying a first downlink transmission and a second downlink transmission, the first downlink transmission being communicated over the same radio resources as the second downlink transmission; and
sending, by the first UE, information related to the first downlink transmission over a device to device (D2D) link after receiving the signal carrying the first downlink transmission, the D2D link extending between the first UE and a second UE, wherein the information related to the first downlink transmission is used by the second UE to decode the second downlink transmission in accordance with a signal interference cancellation technique.
10. The method of claim 9 , wherein the information comprises an encoded bit-stream carried by the first downlink transmission.
11. The method of claim 9 , wherein the information comprises soft information related to the first downlink transmission.
12. The method of claim 9 , wherein the information comprises parity information carried by the first downlink transmission.
13. The method of claim 9 , wherein the first downlink transmission and the second downlink transmission originate from the same transmit point (TP).
14. The method of claim 9 , wherein the first downlink transmission and the second downlink transmission originate from different transmit points (TPs).
15. The method of claim 9 , further comprising:
exchanging information related to the first downlink transmission and information related to the second downlink transmission over the D2D link until both the first downlink transmission and the second downlink transmission have been successfully decoded using the signal interference cancellation technique.
16. A first user equipment (UE) comprising:
a processor; and
a computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
receive a signal carrying a first downlink transmission and a second downlink transmission, the first downlink transmission being communicated over the same radio resources as the second downlink transmission; and
receive information corresponding to the second downlink transmission over a device to device (D2D) link after receiving the signal carrying the first downlink transmission, the D2D link extending between the first UE and a second UE; and
use the information received over the D2D link to decode the first downlink transmission in accordance with an interference cancellation technique.
17. The first UE of claim 16 , wherein the instructions to use the information received over the D2D link to decode the first downlink transmission in accordance with the interference cancellation technique includes instructions to:
perform interference cancellation on the signal in accordance with the information related to the second downlink transmission; and
decode the first downlink transmission after performing interference cancellation on the signal.
18. The first UE of claim 16 , wherein the information related to the second downlink transmission comprises an encoded bit-stream carried by the second downlink transmission.
19. The first UE of claim 16 , wherein the information related to the second downlink transmission comprises soft information related to the second downlink transmission.
20. The first UE of claim 16 , wherein the information related to the second downlink transmission comprises parity information carried in the second downlink transmission.
21. The first UE of claim 16 , wherein the programming further includes instructions to:
exchange information related to the first downlink transmission and information related to the second downlink transmission over the D2D link until both the first downlink transmission and the second downlink transmission have been successfully decoded using the interference cancellation technique.
22. A first user equipment (UE) comprising:
a processor; and
a computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
receive a signal carrying a first downlink transmission and a second downlink transmission, the first downlink transmission being communicated over the same radio resources as the second downlink transmission; and
send information related to the first downlink transmission over a device to device (D2D) link after receiving the signal carrying the first downlink transmission, the D2D link extending between the first UE and a second UE, wherein the information related to the first downlink transmission is used by the second UE to decode the second downlink transmission in accordance with a signal interference cancellation technique.
23. The first UE of claim 22 , wherein the information comprises an encoded bit-stream carried by the first downlink transmission.
24. The first UE of claim 22 , wherein the information comprises soft information related to the first downlink transmission.
25. The first UE of claim 22 , wherein the programming further includes instructions to:
exchange information related to the first downlink transmission and information related to the second downlink transmission over the D2D link until both the first downlink transmission and the second downlink transmission have been successfully decoded using the signal interference cancellation technique.