Reference signal power measurement filtering
A wireless communication device and method for filtering a power measurement of a reference signal received by a wireless communication device, by measuring, with a receiver, a current reference signal power and a current cell specific reference signal (CRS) power of the reference signal; generating, by a processor, a measurement reliability coefficient based on the current reference signal power and the current CRS power; and filtering, by a filter, the current reference signal power using the generated measurement reliability coefficient to generate a filtered reference signal power, wherein the measuring, generating, and filtering are performed in a physical layer.
1. A method for filtering a power measurement of a reference signal received by a wireless communication device, the method comprising:
measuring, with a receiver, a current reference signal power and a current cell specific reference signal (CRS) power of the reference signal;
generating, by a processor, a measurement reliability coefficient based on the current reference signal power and the current CRS power; and
filtering, by a filter, the current reference signal power using the generated measurement reliability coefficient to generate a filtered reference signal power,
wherein the measuring, generating, and filtering are performed in a physical layer, and
wherein the generating the measurement reliability coefficient comprises:
subtracting the current CRS power from the current reference signal power in a log domain to obtain a subtraction result; and
transforming, using a look up table, the subtraction result from the log domain into a linear domain.
2. The method of claim 1 , further comprising:
reporting the filtered reference signal power to a layer that is higher than the physical layer.
3. The method of claim 1 , wherein the reference signal is a Long Term Evolution (LTE) signal, and the current reference signal power is a Reference Signal Received Power (RSRP).
4. The method of claim 1 , wherein the generating the measurement reliability coefficient comprises dividing the current reference signal power by the current CRS power in a linear domain.
5. The method of claim 4 , wherein the measurement reliability coefficient is generated by performing a log to linear operation on a difference of the current reference signal power and the current CRS power to obtain the measurement reliability coefficient.
6. The method of claim 4 , wherein the filtered reference signal power is generated by multiplying the measurement reliability filter coefficient by the current reference signal power to produce a first multiplication result, subtracting the measurement reliability coefficient from a value of one to obtain a subtraction result, multiplying the subtraction result with a previous reference signal power to obtain a second multiplication result, and adding the first multiplication result with the second multiplication result.
7. The method of claim 1 , further comprising:
updating a stored reference signal power with the filtered reference signal power.
8. The method of claim 7 , further comprising:
when a reporting timer reaches a predetermined time, reporting the filtered reference signal power to a layer that is higher than the physical layer.
9. The method of claim 7 , further comprising:
prior to a reporting timer reaching a predetermined time, repeating the measuring, generating, and filtering steps.
10. The method of claim 1 , wherein the filter is an infinite impulse response filter.
11. A wireless communication device configured to filter a power measurement of a received reference signal, the wireless communication device comprising:
a receiver configured to measure a current reference signal power and a current cell specific reference signal (CRS) power of the reference signal;
a processor configured to generate a measurement reliability coefficient based on the current reference signal power and the current CRS power; and
a filter configured to filter the current reference signal power using the generated measurement reliability coefficient to generate a filtered reference signal power,
wherein the measuring, generating, and filtering are performed in a physical layer,
wherein the processor is further configured to generate the measurement reliability coefficient by dividing the current reference signal power by the current CRS power in a linear domain, and
wherein the processor is further configured to generate the filtered reference signal power by multiplying the measurement reliability filter coefficient by the current reference signal power to produce a first multiplication result, subtracting the measurement reliability coefficient from a value of one to obtain a subtraction result, multiplying the subtraction result with a previous reference signal power to obtain a second multiplication result, and adding the first multiplication result with the second multiplication result.
12. The wireless communication device of claim 11 , wherein the processor is further configured to report the filtered reference signal power to a layer that is higher than the physical layer.
13. The wireless communication device of claim 11 , wherein the reference signal is a Long Term Evolution (LTE) signal, and the current reference signal power is Reference Signal Received Power (RSRP).
14. The wireless communication device of claim 11 , wherein the processor is further configured to generate the measurement reliability coefficient by subtracting the current CRS power from the current reference signal power in a log domain and transforming, using a look up table, the subtraction result from the log domain into a linear domain.
15. The wireless communication device of claim 11 , wherein the processor is further configured to generate the measurement reliability coefficient by performing a log to linear operation on a difference of the current reference signal power and the current CRS power to obtain the measurement reliability coefficient.
16. The wireless communication device of claim 11 , wherein the processor is further configured to update a stored reference signal power with the filtered reference signal power.
17. The wireless communication device of claim 16 , wherein when a reporting timer reaches a predetermined time, the processor is further configured to report the updated filtered reference signal power to a layer that is higher than the physical layer.
18. The wireless communication device of claim 16 , wherein prior to a reporting timer reaching a predetermined time, the receiver, processor, and filter are further configured to repeat the measuring, generating, and filtering, respectively.
19. The wireless communication device of claim 11 , wherein the filter is an infinite impulse response filter.
20. A wireless communication device configured to filter power measurement of a received reference signal, the wireless communication device comprising:
a receiving means for measuring a current reference signal power and a current cell specific reference signal (CRS) power of the reference signal;
a processing means for generating a measurement reliability coefficient based on the current reference signal power and the current CRS power; and
a filtering means for filtering the current reference signal power using the generated measurement reliability coefficient to generate a filtered reference signal power,
wherein the measuring, generating, and filtering are performed in a physical layer,
wherein the measurement reliability coefficient is generated by performing a log to linear operation on a difference of the current reference signal power and the current CRS power to obtain the measurement reliability coefficient.
21. A computer program product embodied on a non-transitory computer-readable medium comprising program instructions configured such that the instructions, when executed by processing circuitry, cause the processing circuitry to implement the method of claim 1 .