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US 7,209,712 B2Granted
Mean square estimation of channel quality measure
AssigneeQUALCOMM Incorporated
InventorJack M. Holtzman
Life of this patent
Estimating the term…
Abstract
Methods and apparatus for improving the feedback of channel information to a serving base station, which provides accuracy and reliability of such information. The process determines the received link quality indicators using historical information of the previously received indicators. The method may be applied to full link quality indicators, differential indicators, and/or a combination of both.
Claims40
A method in a wireless communication system, comprising:
- receiving a link quality indicator, the link quality indicator one of a plurality of link quality indicator values;
- determining a conditional probability for each of the plurality of link quality indicator values, wherein the link quality indicator is a full link quality indicator, and wherein the link quality indicator is a measure of the Carrier to Interference ratio (C/I);
- evaluating
- ∑
- i
- =
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- n
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- Ci
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-
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- R
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- ∑
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- =
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- n
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-
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- R
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-
- P
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- ,
- wherein n is the total number of link quality values, Ci represents each link quality indicator, R represents the received link quality indicator, P(|) is a conditional probability operator, and i and j are indices;
- selecting one of the plurality of link quality indicators values based on the conditional probabilities, wherein selecting one of the plurality of link quality indicator values considers the minimum mean square error.
43 more elements
A method in a wireless communication system, comprising:
- receiving a link quality indicator, the link quality indicator one of a plurality of link quality indicator values;
- determining a conditional probability for each of the plurality of link quality indicator values, wherein the link quality indicator is a full link quality indicator, and wherein the link quality indicator is a measure of the Carrier to Interference ratio (C/I);
- estimating the root mean square error of the mean square error as
- E
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- wherein (C{circumflex over (/)}I) is an estimate of the link quality indicator;
- and
- selecting one of the plurality of link quality indicators values based on the conditional probabilities, wherein selecting one of the plurality of link quality indicator values considers the minimum mean square error.
57 more elements
A method in a wireless communication system, comprising:
- receiving a link quality indicator, the link quality indicator one of a plurality of link quality indicator values;
- determining a conditional probability for each of the plurality of link quality indicator values;
- selecting one of the plurality of link quality indicator values based on the conditional probabilities;
- estimating a future channel condition based on the conditional probabilities;
- estimating a probability distribution of likely link quality indicator values,
- wherein estimating the probability distribution further comprises:
- calculating a standard deviation of
- (
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- ^
-
- I
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- =
- π
- 2
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- estimate of average absolute difference;
- and
- storing the estimate of the probability distribution in a memory storage device.
19 more elements
A method in a wireless communication system, comprising:
- receiving a link quality indicator, the link quality indicator one of a plurality of link quality indicator values;
- determining a first estimate of the received link quality indicator;
- determining a second estimate of the received link quality indicator using previously received link quality indicators;
- and
- determining a third estimate of the received link quality indicator as a function of the first and second estimates;
- determining a conditional probability for each of the plurality of link quality indicator values;
- determining a weighting factor as a function of the first and second estimates;
- and
- applying the weighting factor to determining the third estimate, wherein determining the weighting factor comprises:
- calculating
- α
- =
- e
- 2
- e
- 1
- +
- e
- 2
- ,
- wherein e1 is a mean square error of the first estimate and e2 is a mean square error of the second estimate;
- and
- selecting one of the plurality of link quality indicator values based on the conditional probabilities.
20 more elements
A wireless apparatus, comprising:
- means for receiving a link quality indicator, wherein the link quality indicator is a full link quality indicator corresponding to a Carder to Interference ratio (C/I), the apparatus further comprising:
- means for evaluating
- ∑
- i
- =
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- n
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-
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- wherein n is the total number of link quality values, Ci represents each link quality indicator, R represents the received link quality indicator, P(|) is a conditional probability operator, and i and j are indices, the link quality indicator one of a plurality of link quality indicator values;
- means for determining a conditional probability for each of the plurality of link quality indicator values;
- means for selecting one of the plurality of link quality indicator values based on the conditional probabilities;
- and
- means for estimating a minimum mean square error of the conditional probabilities,
- wherein selecting one of the plurality of link quality indicator values considers the minimum mean square error.
46 more elements
A method in a wireless communication system, comprising:
- receiving a link quality indicator, the link quality indicator one of a plurality of link quality indicator values;
- determining a conditional probability for each of the plurality of link quality indicator values;
- and
- selecting one of the plurality of link quality indicator values based on the conditional probabilities;
- and
- estimating a probability distribution of likely link quality indicator values wherein means for estimating the probability distribution further comprises:
- means for calculating a standard deviation of
- (
- C
-
- /
- ^
-
- I
- )
- =
- π
- 2
- ·
- estimate of average absolute difference;
- and
- storing the estimate of the probability distribution in a memory storage device.
19 more elements
A wireless apparatus, comprising:
- means for receiving a link quality indicator, the link quality indicator one of a plurality of link quality indicator values;
- means for determining a first estimate of the received link quality indicator;
- means for determining a second estimate of the received link quality indicator using a previously received link quality indicator;
- and
- means for determining a third estimate of the received link quality indicator as a function of the first and second estimates;
- means for determining a weighting factor as a function of the first and second estimates, wherein means for determining the weighting factor comprises:
- means for calculating
- α
- =
- e
- 2
- e
- 1
- +
- e
- 2
- ,
- wherein e1 is a mean square error of the first estimate and e2 is a mean square error of the second estimate;
- means for applying the weighting factor to determining the third estimate;
- means for determining a conditional probability for each of the plurality of link quality indicator values;
- and
- means for selecting one of the plurality of link quality indicator values based on the conditional probabilities.
19 more elements
A method in a wireless communication system, comprising:
- receiving a plurality of differential link quality indicators;
- and
- for each of the plurality of differential link quality indicators estimating an originally transmitted differential indicator, wherein the originally transmitted differential indicator is one of two binary values, by:
- determining a minimum mean square error for each of the two binary values,
- wherein determining a mean square error comprises:
- for each binary value, evaluating;
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- and
- estimating the originally transmitted as the binary value corresponding to the minimum mean square error.
17 more elements
An apparatus in a wireless communication system, comprising:
- means for receiving a plurality of differential link quality indicators;
- and
- means for estimating an originally transmitted differential indicator for each of the plurality of differential link quality indicators, wherein the originally transmitted differential indicator is one of two binary values, by:
- determining a minimum mean square error for each of the two binary values, wherein determining a mean square error comprises:
- for each binary value, evaluating;
- b
- ^
- =
- tanh
-
- (
- x
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- .
- and
- estimating the originally transmitted as the binary value corresponding to the minimum mean square error.
16 more elements
A wireless infrastructure element, comprising:
- a processor for processing computer readable instructions;
- and
- a memory storage device for storing computer readable instructions for:
- receiving a link quality indicator, wherein the link quality indicator is a full link quality indicator corresponding to a measure of a Carrier to Interference ratio (C/I), and wherein the computer readable instructions are further for:
- evaluating
- ∑
- i
- =
- 1
- n
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- Ci
-
-
- P
-
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- R
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- Ci
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-
- P
-
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- Ci
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- n
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-
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- R
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-
- P
-
- (
- Cj
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- ,
- wherein n is the total number of link quality values, Ci represents each link quality indicator, R represents the received link quality indicator, P(|) is a conditional probability operator, and i and j are indices the link quality indicator one of a plurality of link quality indicator values;
- determining a conditional probability for each of the plurality of link quality indicator values;
- and
- selecting one of the plurality of link quality indicator values based on the conditional probabilities;
- and
- wherein the computer readable instructions are further for:
- estimating a minimum mean square error of the conditional probabilities,
- wherein selecting one of the plurality of link quality indicator values considers the minimum mean square error.
52 more elements
A wireless infrastructure element, comprising:
- a processor for processing computer readable instructions;
- and
- a memory storage device for storing computer readable instructions for:
- receiving a link quality indicator, the link quality indicator one of a plurality of link quality indicator values;
- determining a conditional probability for each of the plurality of link quality indicator values;
- and
- selecting one of the plurality of link quality indicator values based on the conditional probabilities,
- wherein the computer readable instructions are further for:
- determining a first estimate of the received link quality indicator;
- calculating
- α
- =
- e
- 2
- e
- 1
- +
- e
- 2
- ,
- wherein e1 is a mean square error of the first
- estimate and e2 is a mean square error of the second estimate;
- and
- determining a second estimate of the received link quality indicator using a previously received link quality indicator;
- determining a third estimate of the received link quality indicator as a function of the first and second estimates;
- determining a weighting factor as a function of the first and second estimates;
- and
- applying the weighting factor to determining the third estimate.
25 more elements
Dependencies are inferred from the claim text.