Platform noise estimation and mitigation for wireless receivers
View Patent ↗An apparatus and method suitable to estimate impairments of wireless signals, including both noise and interference of the wireless signals are disclosed herein. The noise of the wireless signals may be caused by thermal noise and platform noise. An adaptive scheme may dynamically switch between estimating interference only or the combined noise and interference. Other embodiments may be disclosed or claimed.
1. An apparatus comprising:
a multipath antenna configured to receive wireless signals;
an estimator coupled to the multipath antenna and configured to:
perform a first estimation of impairments of the wireless signals indicative of interference and additive white Gaussian noise (AWGN) of the wireless signals,
perform a second estimation of the impairments of the wireless signals indicative of the interference and platform noise of the wireless signals, and
determine whether a difference between the first estimation and the second estimation is more than a predetermined threshold; and
a decoder configured to decode the wireless signals based on a result of said determination.
2. The apparatus of claim 1 , wherein the estimator is further configured to perform the second estimation based on temporal and spatial correlation of the impairments of the wireless signals.
3. The apparatus of claim 1 , wherein the estimator is further configured to perform the first estimation based on temporal correlation and spatial correlation of the impairments of the wireless signals.
4. The apparatus of claim 1 , wherein the estimator is configured to perform the second estimation based on a received pilot symbol, an estimated channel, a transmitted pilot symbol, and a number of pilot symbols over one time slot.
5. The apparatus of claim 1 , wherein the estimator is configured to perform the first estimation based on an estimation of a transmit power of a base station and a power of the AGWN of the wireless signals.
6. The apparatus of claim 5 , wherein the decoder is further configured to decode the wireless signals based on the first estimation in response to a determination that the difference between the first estimation and the second estimation is smaller than the pre-defined threshold; or
decode the wireless signals based on the second estimation in response to a determination that the difference between the first estimation and the second estimation is no smaller than the pre-defined threshold.
7. The apparatus of claim 1 , wherein the predetermined threshold is about 10%.
8. The apparatus of claim 1 , further comprising a combiner to combine the wireless signals.
9. A method, comprising:
receiving wireless signals;
performing a first estimation of impairments of the wireless signals indicative of interference and additive white Gaussian noise (AWGN) of the wireless signals;
performing a second estimation of the impairments of the wireless signals indicative of the interference and platform noise of the wireless signals;
comparing the first estimation to the second estimation; and
mitigating an effect of the impairments of the wireless signals based on said comparing.
10. The method of claim 9 , wherein determining the first estimation further includes estimating the interference of the wireless signals caused by intra-cell interference, inter-cell interference and inter-symbol interference of the wireless signals.
11. The method of claim 9 , wherein determining the second estimation further includes estimating a combined noise and interference covariance matrix based on received pilot symbols, estimated channel of respective ones of the received pilot symbols, transmitted pilot symbols, and number of pilot symbols over one time slot.
12. The method of claim 9 , further comprising averaging, by the station, a plurality of second estimations corresponding to a plurality of time slots, respectively, based on an infinite impulse response filter.
13. The method of claim 9 , wherein said comparing comprises determining whether a difference between the first estimation and the second estimation is more than a predetermined threshold and the method further comprises:
decoding, by the station, the wireless signals based on the first estimation in response to a determination that the difference is within the pre-defined threshold.
14. The method of claim 9 , wherein said comparing comprises determining whether a difference between the first estimation and the second estimation is more than a predetermined threshold and the method further comprises:
decoding, by the station, the wireless signals based on the second estimation in response to a determination that the difference exceeds the pre-defined threshold.
15. The method of claim 9 , wherein said comparing comprises determining whether a difference between the first estimation and the second estimation is more than about 10%.
16. A system comprising:
one or more antenna units to receive wireless signals;
a data bus coupled to the one or more antenna units;
a receiver operatively coupled to the data bus and the one or more antenna units to:
perform a first estimation of impairments of the wireless signals indicative of interference and additive white Gaussian noise (AWGN) of the wireless signals,
perform a second estimation of the impairments of the wireless signals indicative of the interference and platform noise of the wireless signals, wherein the platform noise includes noise caused by the data bus of the system,
compare a temporal correlation and a spatial correlation of the first estimation and the second estimation, and
determine whether a first difference between the temporal correlation of the first estimation and the second estimation, and a second difference between the spatial correlation of the first estimation and the second estimation are both more than a predetermined threshold; and
a decoder to decode the wireless signals based on said determination.
17. The system of claim 16 , wherein the predetermined threshold is about 10%.
18. The system of claim 16 , wherein to perform the second estimation further includes to estimate the impairments of the wireless signals based on received pilot symbol, estimated channel, transmitted pilot symbol, and number of pilot symbols in one time slot.
19. The system of claim 16 , wherein the receiver is further configured to average a plurality of second estimations corresponding to a plurality of time slots, respectively, based on an infinite impulse response filter.
20. The system of claim 16 , wherein the decoder to decode the wireless signals further includes the decoder to decode the wireless signals based on the second estimation in response to a determination that the first difference and the second difference are both more than the predetermined threshold.