Granted Patent B2

US 9,467,181 · App. 14/710,828 · Granted Oct 11, 2016

Abstract

Claims (176)

1. A method of determining a noise estimate in case of receiver power unbalanced antennas, said method comprising:

receiving radio frequency signal at least from an interference source through a plurality of antennas over different propagation paths and processing paths;

determining a covariance matrix estimate based on the received radio frequency signal; and

determining the noise estimate by calculating

N

^

=

T

-

T

2

-

4

⁢

Δ

2

,

wherein {circumflex over (N)} is the noise estimate; and

Δ=c 11 c 22 −c 12 c 21 ;

T=c 11 +c 22 ; and

c jk , where j, k=1, 2, are elements of the covariance matrix estimate relating to two antennas of the plurality of antennas.

2. The method according to claim 1 ,

wherein the received radio frequency signal only comprises a radio frequency signal transmitted from at least one interference source in absence of an intended data or control radio frequency signal.

3. The method according to claim 2 , further comprising:

determining a quotient Q:

Q

=

c

11

⁢

c

22

c

12

⁢

c

21

;

performing at least one of

determining whether the quotient is approximately 1, Q≈1, which is indicative of the contribution of the interference signal strength being significantly bigger than the contribution of the noise; and

determining whether the quotient is significantly bigger than 1, Q>>1, which is indicative of the contribution of the noise being significantly bigger than the contribution of the interference signal strength.

4. The method according to claim 1 ,

wherein the received radio frequency signal comprises a radio frequency signal transmitted from at least one interference source and a radio frequency signal transmitted from a transmitter, wherein the radio frequency signal transmitted from the transmitter comprises at least one of a data and a control radio frequency signal,

the method further comprising:

storing the received radio frequency signal;

regenerating a radio frequency signal representative of the radio frequency signal transmitted from the transmitter; and

cancelling the regenerated radio frequency signal from the stored received radio frequency signal to obtain a residual radio frequency signal,

wherein the covariance matrix estimate is determined based on the residual radio frequency signal of the received radio frequency signal.

5. The method according to claim 4 ,

wherein the radio frequency signal representative of the radio frequency signal transmitted from the transmitter is regenerated based on a channel response estimate.

6. The method according to claim 4 , further comprising:

determining a quotient Q:

Q

=

c

11

⁢

c

22

c

12

⁢

c

21

;

performing at least one of

determining whether the quotient is approximately 1, Q≈1, which is indicative of the contribution of the interference signal strength being significantly bigger than the contribution of the noise; and

determining whether the quotient is significantly bigger than 1, Q>>1, which is indicative of the contribution of the noise being significantly bigger than the contribution of the interference signal strength.

7. The method according to claim 1 , further comprising:

determining whether the contribution of the noise is significantly bigger than the contribution of the interference signal strength; and

if this applies, determining the noise estimate by calculating

{circumflex over ( N )}≈min{ c 11 ,c 22 }.

8. The method according to claim 1 , further comprising:

determining whether the contribution of the interference signal strength is significantly bigger than the contribution of the noise; and

if this applies, determining the noise estimate by calculating

N

^

≈

Δ

T

.

9. A radio frequency receiver capable of determining a noise estimate in case of received power unbalanced antennas, the apparatus comprising:

a plurality of antennas for receiving a radio frequency signal from an interference source over different propagation paths and processing paths;

a covariance matrix estimator coupled through separate processing paths to a respective one of the plurality of antennas and arranged to determine an estimate of a covariance matrix based on the received radio frequency signal; and

wherein the noise estimator is further arranged to calculate

N

^

=

T

-

T

2

-

4

⁢

Δ

2

,

wherein {circumflex over (N)} is the noise estimate; and

Δ=c 11 c 22 −c 12 c 21 ;

T=c 11 +c 22 ; and

c jk are elements of the covariance matrix estimate.

10. The radio frequency receiver according to claim 9 ,

wherein the received radio frequency signal comprises a radio frequency signal transmitted from at least one interference source and a radio frequency signal transmitted from a transmitter, wherein the radio frequency signal transmitted from the transmitter comprises at least one of a data and a control radio frequency signal intended for being decoded at the receiver,

the radio frequency receiver further comprising:

a buffer arranged in the processing paths, coupled to the covariance matrix estimator and provided to store the received radio frequency signal;

a signal regenerator coupled to a decoder and arranged to regenerate a radio frequency signal representative of the radio frequency signal transmitted from the transmitter; and

a signal cancellator arranged to cancel the regenerated radio frequency signal from the stored received radio frequency signal to obtain a residual radio frequency signal,

wherein the covariance matrix estimator is arranged to determine the estimate of the covariance matrix based on the residual radio frequency signal of the received radio frequency signal.

11. The radio frequency receiver according to claim 10 , further comprising:

a channel response estimator coupled through separate processing paths to a respective one of the plurality of antennas and arranged to determine an estimate of a channel response based on the received radio frequency signal.

12. The radio frequency receiver according to claim 9 ,

wherein in case the contribution of the noise is significantly bigger than the contribution of the interference signal strength, the noise estimator is further arranged to determine the noise estimate by calculating

{circumflex over ( N )}≈min{ c 11 ,c 22 }.

13. The receiver according to claim 12 , wherein the noise estimator is further arranged to determine a quotient Q:

Q

=

c

11

⁢

c

22

c

12

⁢

c

21

;

and arranged to perform at least one of

determining whether the quotient is approximately 1, Q≈1, which is indicative of the contribution of the interference signal strength is significantly bigger than the contribution of the noise, and

determining whether the quotient is significantly bigger than 1, Q>>1, which is indicative of the contribution of the noise is significantly bigger than the contribution of the interference signal strength.

14. The radio frequency receiver according to claim 9 ,

wherein in case the contribution of the interference signal strength is significantly bigger than the contribution of the noise, the noise estimator is further arranged to determine the noise estimate by calculating

N

^

≈

Δ

T

.

15. The receiver according to claim 14 , wherein the noise estimator is further arranged to determine a quotient Q:

Q

=

c

11

⁢

c

22

c

12

⁢

c

21

;

and arranged to perform at least one of

determining whether the quotient is approximately 1, Q≈1, which is indicative of the contribution of the interference signal strength is significantly bigger than the contribution of the noise, and

determining whether the quotient is significantly bigger than 1, Q>>1, which is indicative of the contribution of the noise is significantly bigger than the contribution of the interference signal strength.

16. A non-transitory, tangible computer readable storage medium bearing computer executable instructions for operating a radio frequency receiver capable of determining a noise estimate in case of unbalanced antennas, wherein the instructions, when executing on one or more processing devices, cause the one or more processing devices to perform a method comprising:

determining a covariance matrix estimate based on a radio frequency signal received at least from an interference source through a plurality of antennas over different propagation paths and processing paths; and

determining a noise estimate by calculating

N

^

=

T

-

T

2

-

4

⁢

Δ

2

,

wherein {circumflex over (N)} is the noise estimate; and

Δ=c 11 c 22 −c 12 c 21 ;

T=c 11 +c 22 ; and

c jk , where j, k=1, 2, are elements of the covariance matrix estimate relating to two antennas of the plurality of antennas.

Assignments (14)