Cooperative interference subtraction scheme

1. A method for subtracting interference in a wireless communications network, the method comprising:

receiving a first baseband signal including an interference signal at a first base station;

receiving a second baseband signal including the interference signal at a second base station;

calculating a channel translation parameter based on the first baseband signal and the second baseband signal;

receiving a signal including a user equipment (UE) transmission at the first base station during a first time slot; and

subtracting interference from the signal including the UE transmission using the channel translation parameter,

wherein subtracting interference from the signal including the UE transmission includes:

receiving a signal including a UE transmission at the second base station during the first time slot;

decoding the UE transmission received at the second base station; and

subtracting the UE transmission from the signal including the UE transmission received by the second base station to create an interference signal,

wherein the interference subtracted from the signal received at the first base station is a result of subtracting the UE transmission from the signal including the UE transmission received by the second base station.

2. The method of claim 1 , wherein the channel translation parameter is a ratio between the first baseband signal and the second baseband signal.

3. The method of claim 1 , wherein subtracting interference from the signal including the UE transmission includes:

reconstructing the interference signal by multiplying a signal received by the second base station during a quiet time for the second base station by the channel translation parameter.

4. The method of claim 1 , wherein the first time slot is a quiet time for the second base station.

5. The method of claim 1 , further comprising scheduling a quiet time at the first base station and the second base station, wherein the first and second baseband signals are received during the quiet time.

6. The method of claim 1 , further comprising cancelling interference from the first baseband signal.

7. The method of claim 1 , further comprising:

evaluating a plurality of candidate base stations; and

designating one of the plurality of candidate base stations as the second base station based on the results of the evaluation.

8. The method of claim 1 , further comprising:

calculating a second channel translation parameter for the second base station and a third base station;

receiving a second signal from UE at the third base station; and

subtracting interference from the second received signal using the second channel translation parameter.

9. The method of claim 1 , wherein subtracting the interference from the received signal is performed according to the following equation:

r A ( t 1 ) = r A,UE ( t 1 )+ h A I ( t 1 )+ n A ( t 1 )−β A,B r B ( t 1 )= r A,UE ( t 1 )+ {circumflex over (n)} A ( t 1 )

in which {circumflex over (n)} A (t 1 ) represents noise due to the interference estimation process in addition to additive white Gaussian noise (AWGN) at the first base station, r A,UE (t 1 ) represents the signal from UE at time t 1 , h A I(t 1 ) represents interference received by the first base station at time t 1 , n A (t 1 ) represents noise received by the first base station at time t 1 , β A,B is the channel translation parameter, and r B (t 1 ) represents a signal receive at the second base station at time t 1 .

10. The method of claim 1 , wherein the channel translation parameter is calculated according to the following equation:

r

A

⁡

(

t

q

)

r

B

⁡

(

t

q

)

=

β

A

,

B

in which r A is the first baseband signal, r B is the second baseband signal, and β A,B is the channel translation parameter.

11. An interference subtraction system for wireless communications, the system comprising:

a first base station that receives a first baseband signal including an interference signal and receives a signal including a user equipment (UE) transmission during a first time slot;

a second base station that receives a second baseband signal including the interference signal;

a processor;

a memory; and

a non-transitory computer readable medium with computer executable instructions stored thereon which, when executed by the processor, perform the following operations:

calculating a channel translation parameter based on the first baseband signal and the second baseband signal; and

subtracting interference from the signal including the UE transmission using the channel translation parameter,

wherein subtracting interference from the signal including the UE transmission includes:

receiving a signal including a UE transmission at the second base station during the first time slot;

decoding the UE transmission received at the second base station; and

subtracting the UE transmission from the signal including the UE transmission received by the second base station to create an interference signal,

wherein the interference subtracted from the signal received at the first base station is a result of subtracting the UE transmission from the signal including the UE transmission received by the second base station.

12. The system of claim 11 , wherein the channel translation parameter is a ratio between the first baseband signal and the second baseband signal.

13. The system of claim 11 , wherein subtracting interference from the signal including the UE transmission includes:

reconstructing the interference signal by multiplying a signal received by the second base station during a quiet time for the second base station by the channel translation parameter.

14. The system of claim 11 , wherein a quiet time is scheduled at the first base station and the second base station, and wherein the first and second baseband signals are received during the quiet time.

15. The system of claim 11 , wherein the operations further comprise:

evaluating a plurality of candidate base stations; and

designating one of the plurality of candidate base stations as the second base station based on the results of the evaluation.

16. A method for subtracting interference in a wireless communications network, the method comprising:

receiving a first baseband signal including an interference signal at a first base station;

receiving a second baseband signal including the interference signal at a second base station;

calculating a channel translation parameter based on the first baseband signal and the second baseband signal;

receiving a signal including a user equipment (UE) transmission at the first base station during a first time slot;

subtracting interference from the signal including the UE transmission using the channel translation parameter;

decoding the signal including the UE transmission;

reconstructing the UE transmission from the decoded signal;

subtracting the reconstructed UE transmission from the signal including the UE transmission to create a second interference signal; and

subtracting the second interference signal from a signal received at a third base station.

17. An interference subtraction system for wireless communications, the system comprising:

a first base station that receives a first baseband signal including an interference signal and receives a signal including a user equipment (UE) transmission during a first time slot;

a second base station that receives a second baseband signal including the interference signal;

a third base station that receives a third signal;

a processor;

a memory; and

a non-transitory computer readable medium with computer executable instructions stored thereon which, when executed by the processor, perform the following operations:

calculating a channel translation parameter based on the first baseband signal and the second baseband signal;

subtracting interference from the signal including the UE transmission using the channel translation parameter;

decoding the signal including the UE transmission;

reconstructing a UE transmission from the decoded signal;

subtracting the reconstructed UE transmission from the signal including the UE transmission to create a second interference signal; and

subtracting the second interference signal from the third signal received at the third base station.