Methods and apparatuses of measuring impulse noise parameters in multi-carrier communication systems
A method and apparatus for measuring and tracking Impulse Noise parameters in a communication system are described. The method includes estimating one or more parameters of the impulse noise, the parameters including a period, an offset and duration of the impulse noise.
1. A method for estimation of impulse noise within frames of a multi-carrier system, each of the frames being characterized by a frame number from a plurality of frame numbers, the method comprising:
detecting the frames of the multi-carrier system that are affected by the impulse noise;
estimating one or more parameters of the impulse noise using the frame numbers of the frames that are affected by the impulse noise,
wherein the one or more parameters of the impulse noise comprise a period, an offset, and a duration of the impulse noise; and
predicting a position of future frames affected by the impulse noise using the one or more parameters of the impulse noise.
2. The method recited in claim 1 , wherein the one or more parameters of the impulse noise are estimated using only the frame numbers of the frames that are affected by the impulse noise.
3. The method recited in claim 1 , wherein estimating the one or more parameters comprises:
averaging the frame numbers of the frames that are affected by the impulse noise.
4. The method recited in claim 3 , wherein averaging the frame numbers comprises:
evaluating the equation:
D
=
1
N
∑
j
=
0
N
-
1
D
i
-
j
,
where D i represents a number of consecutive impulsive frames for an i th detected impulse, and N represents an averaging window.
5. The method recited in claim 1 , wherein estimating the one or more parameters comprises:
estimating the offset and the period of the impulse noise using a second order feedback loop.
6. The method recited in claim 5 , wherein the feedback loop forces an error between an instantaneous period value and a previous period value to zero.
7. The method recited in claim 5 , wherein the feedback loop forces an error between an instantaneous offset value and a previous offset value to zero.
8. The method recited in claim 1 , wherein estimating the one or more parameters comprises:
estimating the offset and the period of the impulse noise using one of a minimum mean square error algorithm or a least means square algorithm.
9. The method recited in claim 1 , further comprising:
determining a signal-to-noise ratio based upon the frames that are affected by the impulse noise; and
performing bit-loading based on the signal-to-noise ratio.
10. An apparatus for estimation of impulse noise within frames of a multiple tone signal, each of the frames being characterized by a frame number from a plurality of frame numbers, comprising:
a detector module configured to detect the frames of the multiple tone signal that are affected by the impulse noise, and
an impulse noise parameter measurement module configured to estimate one or more parameters of the impulse noise using the frame numbers of the frames that are affected by the impulse noise,
wherein the one or more parameters of the impulse noise comprise a period, an offset, and a duration of the impulse noise, and
wherein the detector module is configured to predict a position of a future frame affected by the impulse noise using the one or more parameters of the impulse noise.
11. The apparatus recited in claim 10 , wherein the impulse noise parameter measurement module is further configured to estimate the one or more parameters of the impulse noise using only frame numbers of the frames that are affected by the impulse noise.
12. The apparatus recited in claim 10 , wherein the impulse noise parameter measurement module is configured to estimate the duration of impulse noise by averaging the frame numbers that are affected by the impulse noise.
13. The apparatus recited in claim 12 , wherein the impulse noise parameter measurement module is further configured to average the frame numbers by evaluating the equation:
D
=
1
N
∑
j
=
0
N
-
1
D
i
-
j
,
where D i represents a number of consecutive impulsive frames for an i th detected impulse, and N represents an averaging window.
14. The apparatus recited in claim 10 , wherein the impulse noise parameter measurement module comprises:
a feedback loop configured to estimate the offset and the period of the impulse noise.
15. The apparatus recited in claim 14 , wherein the feedback loop is configured to force an error between an instantaneous period value and a previous period value to zero.
16. The apparatus recited in claim 14 , wherein the feedback loop is configured to force an error between an instantaneous offset value and a previous offset value to zero.
17. The apparatus recited in claim 10 , wherein the impulse noise parameter measurement module is configured to estimate the offset and the period of the impulse noise using one of a minimum mean square error algorithm or a least means square algorithm.
18. The apparatus recited in claim 10 , further comprising:
a signal-to-noise ratio module, coupled to the detector module, configured to determine a signal-to-noise ratio based on the frames that are affected by the impulse noise; and
a bit-loading module, coupled to the signal-to-noise ratio module, configured to determine a bit rate based on the signal-to-noise ratio.
19. The apparatus recited in claim 10 , wherein the multi-tone transceiver is implemented as part of a set top box employing a digital subscriber line modem.