Adaptive Filtering of Cell Measurements

1. A method for adaptive filtering of cell measurements, the method comprising a wireless communication device: calculating a first filtered measurement of a cell in a network, wherein the first filtered measurement is based on a network configured filter coefficient, the first filtered measurement indicative of a channel condition of the cell over a first measurement period; determining, based at least in part on a plurality of instantaneous measurement samples of the cell captured over a second measurement period, that a fading condition of the cell over the second measurement period exceeds a first threshold; modifying the network configured filter coefficient to derive a modified filter coefficient in response to the fading condition of the cell exceeding the first threshold over the second measurement period; filtering the plurality of instantaneous measurement samples based on the modified filter coefficient to calculate a second filtered measurement of the cell; comparing the first filtered measurement and the second filtered measurement; in an instance in which a difference between the second filtered measurement and the first filtered measurement exceeds a second threshold: clipping the second filtered measurement to derive a clipped value; and calculating an adjusted measurement value for the cell based at least in part on the clipped value; in an instance in which the difference between the second filtered measurement and the first filtered measurement does not exceed the second threshold, calculating the adjusted measurement value directly from the second filtered measurement; and using the adjusted measurement value for event evaluation and reporting.

2. The method of claim 1 , wherein the cell comprises a cell of a network using a Long Term Evolution (LTE) technology, and wherein the plurality of instantaneous measurement samples comprises one or more of a reference signal received power (RSRP) value or a reference signal received quality (RSRQ) value.

3. The method of claim 1 , wherein determining that the fading condition of the cell exceeds the first threshold comprises: calculating a variance of the plurality of instantaneous measurement samples of the cell captured over the second measurement period; and determining that the variance exceeds the first threshold.

4. The method of claim 1 , wherein modifying the network configured filter coefficient comprises increasing the network configured filter coefficient by a factor k.

5. The method of claim 4 , wherein k is a static value.

6. The method of claim 4 , wherein k is a value selected based at least in part on an extent of the fading condition over the second measurement period.

7. The method of claim 1 , wherein the plurality of instantaneous measurement samples are filtered based on the network configured filter coefficient in an instance in which the fading condition of the cell does not exceed the first threshold over the second measurement period.

8. The method of claim 1 , further comprising the wireless communication device: capturing a plurality of instantaneous measurement samples over a third measurement period; determining based at least in part on the plurality of instantaneous measurement samples captured over the third measurement period that a fading condition over the third measurement period does not exceed the first threshold; and resuming usage of the network configured filter coefficient in response to the fading condition over the third measurement period not exceeding the first threshold.

9. A method for adaptive filtering of cell measurements of a cell in a network, the method comprising a wireless communication device: determining a weighted variance of a plurality of instantaneous measurement samples of the cell captured over a measurement period. wherein the weighted variance comprises a weighted sum of squared terms; determining based at least in part on the weighted variance, that a fading condition of the cell over the measurement period exceeds a threshold; modifying a network configured filter coefficient to derive a modified filter coefficient in response to the fading condition of the cell exceeding the threshold over the measurement period; filtering the plurality of instantaneous measurement samples based on the modified filter coefficient to calculate a filtered measurement of the cell; calculating an adjusted measurement value for the cell based at least in part on the filtered measurement; and using the adjusted measurement value for event evaluation and reporting.

10. The method of claim 9 , further comprising: obtaining a first sampling rate defined by the network; selecting a second sampling rate; and determining the plurality of instantaneous measurement samples based on the second sampling rate, wherein the second sampling rate is based on the first sampling rate and the network configured filter coefficient.

11. The method of claim 1 , further comprising: obtaining a first sampling rate defined by the network; selecting a second sampling rate; and determining the plurality of instantaneous measurement samples based on the second sampling rate, wherein the second sampling rate is based on the first sampling rate and the network configured filter coefficient.

12. The method of claim 9 , further comprising: comparing the filtered measurement and a second filtered measurement calculated for a previous measurement period based on the network configured filter coefficient; and in an instance in which a difference between the filtered measurement and the second filtered measurement exceeds a second threshold, calculating the adjusted measurement value comprises: clipping the filtered measurement to derive a clipped value; and calculating the adjusted measurement value based at least in part on the clipped value.

13. The method of claim 9 , wherein the cell comprises a cell of a network using a Long Term Evolution (LTE) technology, and wherein calculating the adjusted measurement value comprises calculating one or more of a reference signal received power (RSRP) value or a reference signal received quality (RSRQ) value.

14. The method of claim 9 , wherein modifying the network configured filter coefficient comprises increasing the network configured filter coefficient by a factor k.

15. The method of claim 14 , wherein k is a static value.

16. A wireless communication device comprising: a transceiver configured to transmit data to and receive data from a network; and processing circuitry coupled to the transceiver, the processing circuitry configured to control the wireless communication device to at least: determine based at least in part on a plurality of instantaneous measurement samples of a cell in the network that a fading condition of the cell over a measurement period exceeds a threshold; modify a network configured filter coefficient to derive a modified filter coefficient in response to the fading condition of the cell exceeding the threshold over the measurement period; filter the plurality of instantaneous measurement samples based on the modified filter coefficient to calculate a filtered measurement of the cell; derive a first value by clipping the filtered measurement when a difference of the filtered measurement and a second filtered measurement exceeds a second threshold; set the first value equal to the filtered measurement when the difference does not exceed the second threshold; calculate an adjusted measurement value for the cell based at least in part on the first value; and use the adjusted measurement value for event evaluation and reporting.

17. The wireless communication device of claim 16 , wherein the cellular network is a network using a Long Term Evolution (LTE) technology, and wherein the plurality of instantaneous measurement samples comprises one or more of a reference signal received power (RSRP) value or a reference signal received quality (RSRQ) value for the cell.

18. The wireless communication device of claim 16 , wherein the processing circuitry is further configured to control the wireless communication device to determine that the fading condition of the cell exceeds the threshold at least in part by: calculating a variance of the plurality of instantaneous measurement samples of the cell captured over the measurement period; and determining that the variance exceeds the threshold.

19. The wireless communication device of claim 16 , wherein the processing circuitry is further configured to control the wireless communication device to modify the network configured filter coefficient at least in part by increasing the network configured filter coefficient by a factor k.

20. A computer program product for adaptive filtering of cell measurements, the computer program product comprising at least one non-transitory computer readable storage medium having computer program code stored thereon, the computer program code comprising: program code for determining a weighted variance of a plurality of instantaneous measurement samples of a cell in a network, wherein the weighted variance comprises a weighted sum of squared terms; program code for determining, based at least in part on the weighted variance, that a fading condition of the cell over a measurement period exceeds a threshold; program code for modifying a network configured filter coefficient to derive a modified filter coefficient in response to the fading condition of the cell exceeding the threshold over the measurement period; program code for filtering the plurality of instantaneous measurement samples based on the modified filter coefficient to calculate a filtered measurement of the cell; program code for calculating an adjusted measurement value for the cell based at least in part on the filtered measurement; and program code for using the adjusted measurement value for event evaluation and reporting.

21. The computer program product of claim 20 , further comprising: program code for comparing the filtered measurement and a second filtered measurement calculated for a previous measurement period based on the network configured filter coefficient; program code for clipping the filtered measurement to derive a clipped value in an instance in which a difference between the filtered measurement and the second filtered measurement exceeds a second threshold; and program code for calculating the adjusted measurement value based at least in part on the clipped value in an instance in which the difference between the filtered measurement and the second filtered measurement exceeds a second threshold.

22. The computer program product of claim 20 , wherein the cell comprises a cell of a network using a Long Term Evolution (LTE) technology, and wherein the plurality of instantaneous measurement samples comprises one or more of a reference signal received power (RSRP) value or a reference signal received quality (RSRQ) value.

23. The computer program product of claim 20 , wherein the program code for modifying the network configured filter coefficient comprises program code for increasing the network configured filter coefficient by a factor k.

24. The computer program product of claim 20 , further comprising: computer code for obtaining a first sampling rate defined by the network; computer code for selecting a second sampling rate; and computer code for determining the plurality of instantaneous measurement samples based on the second sampling rate, wherein the second sampling rate is based on the first sampling rate and the network configured filter coefficient.