Link adaptation for OFDM systems
AssigneeMarvell International Ltd.
InventorsJungwon Lee, Jihwan P. Choi, Hui-Ling Lou
Life of this patent
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Abstract
A method of adaptively selecting a modulation and coding scheme (MCS) of a communication link includes obtaining a first parameter corresponding to a Quality of Service (QoS) requirement of the communication link, obtaining a second parameter indicative of a physical condition of the communication link, selecting an MCS based on at least the first parameter and the second parameter.
Claims48
A method of adaptively selecting a modulation and coding scheme (MCS) of a communication link, the method comprising:
- obtaining a first parameter corresponding to a Quality of Service (QoS) requirement of the communication link;
- obtaining a second parameter indicative of a physical condition of the communication link, wherein obtaining the second parameter includes estimating an instantaneous value of Carrier-to-Interference-plus-Noise Ratio (CINR) according to a formula:
- η
- CINR_dB
-
- [
- k
- ]
- =
- 10
-
-
- log
- 10
-
- (
- 10
- μ
- CINR_dB
-
- [
- k
- ]
- /
- 10
- -
- α
- ·
- 10
- σ
- CINR_dB
-
- [
- k
- ]
- /
- 10
- )
- ,
- wherein
- μCINR—dB[k] is a mean of a plurality of CINR measurements in decibels at a time k,
- σCINR—dB[k] is a standard deviation of the plurality of CINR measurements at the time k, and
- α is a coefficient to select a degree of confidence of estimating the instantaneous value of CINR;
- and
- selecting an MCS as a function of at least the first parameter, the second parameter, and a given packet length.
A device comprising:
- a first module, implemented in hardware, configured to obtain a CINR measurement indicative of a physical condition of a communication link, wherein the first module utilizes a plurality of Carrier-to-Interference-plus-Noise Ratio (CINR) measurements including the CINR measurement to calculate an instantaneous value of CINR according to a formula:
- η
- CINR_dB
-
- [
- k
- ]
- =
- 10
-
-
- log
- 10
-
- (
- 10
- μ
- CINR_dB
-
- [
- k
- ]
- /
- 10
- -
- α
- ·
- 10
- σ
- CINR_dB
-
- [
- k
- ]
- /
- 10
- )
- ,
- wherein
- μCINR—dB[k] is a mean of the plurality of CINR measurements in decibels at a time k,
- σCINR—dB[k] is a standard deviation of the plurality of CINR measurements at the time k, and
- α is a coefficient to select a degree of confidence of estimating the instantaneous value of CINR;
- a second module, implemented in hardware, configured to select a modulation and coding scheme (MCS) as a function of at least the instantaneous CINR measurement, a parameter corresponding to a Quality of Service (QoS) requirement of the communication link, and a given packet length.
A method of estimating an instantaneous value of a Carrier-to-Interference-plus-Noise Ratio (CINR) indicative of a quality of an OFDM communication link, comprising:
- obtaining a plurality of measurements indicative of the quality of the OFDM communication link, each of the plurality of measurements corresponding to a different time within a time interval;
- calculating a mean based on the plurality of measurements;
- calculating a standard deviation of the plurality of measurements;
- and
- calculating the instantaneous value of the CINR using the mean and the standard deviation.
An apparatus for estimating an instantaneous value of a Carrier-to-Interference-plus-Noise Ratio (CINR) indicative of a quality of an OFDM communication link, the apparatus comprising:
- a first module, implemented in hardware, configured to calculate a mean of a plurality of measurements indicative of the quality of the OFDM communication link, wherein each of the plurality of measurements corresponds to a different time within a time interval;
- a second module, implemented in hardware, configured to calculate a standard deviation of the plurality of measurements;
- and
- a third module, implemented in hardware, configured to calculate the instantaneous value of the CINR using the mean and the standard deviation.
A device comprising:
- a memory to store a plurality of modulation and coding scheme (MCS) values corresponding to different tuples, each tuple including a first element associated with a first parameter indicative of a physical condition of a communication link, a second element associated with a second parameter corresponding to a Quality of Service (QoS) requirement of the communication link, and a third element associated with a given packet length;
- a CINR measurement module configured to obtain the first parameter by utilizing a plurality of Carrier-to-Interference-plus-Noise Ratio (CINR) measurements to calculate an instantaneous value of CINR according to a formula:
- η
- CINR_dB
-
- [
- k
- ]
- =
- 10
-
-
- log
- 10
-
- (
- 10
- μ
- CINR_dB
-
- [
- k
- ]
- /
- 10
- -
- α
- ·
- 10
- σ
- CINR_dB
-
- [
- k
- ]
- /
- 10
- )
- ,
- wherein
- μCINR—dB[k] is a mean of the plurality of CINR measurements in decibels at a time k,
- σCINR—dB[k] is a standard deviation of the plurality of CINR measurements at the time k, and
- α is a coefficient to select a degree of confidence of estimating the instantaneous value of CINR;
- and
- a link adaptation module to select an MCS value from the plurality of MCS values based on the first parameter, the second parameter, and the given packet length.
Dependencies are inferred from the claim text.