Computation of soft bits for a turbo decoder in a communication receiver
First Claim
1. A method on a communication receiver having a soft bit generator and a turbo decoder, the method for computing a threshold Sthi used in demodulating a quadrature amplitude modulated (QAM) signal received by the communication receiver to generate a plurality of soft bits per received symbol for input to the turbo decoder, the method including the steps of:
- the soft bit generator;
computing a mean amplitude A of the received symbols;
multiplying the mean amplitude A by a constant Ci for a square QAM constellation with 4m points, such that
Sthi=A×
Ci where m is a positive integer and I is a positive integer from 1 to (√
{square root over (4m-1)})−
1;
computing one or more of the soft bits from the threshold Sthi; and
outputting the computed soft bits to the turbo decoder.
2 Assignments
0 Petitions
Accused Products
Abstract
A device (20) for computing a threshold Sthi used in demodulating a quadrature amplitude modulated (QAM) signal to generate a plurality of soft bits per received symbol for input to a turbo decoder, the device including: means (30) for computing the mean amplitude A of the received symbols and multiplying the mean amplitude A by of the received symbols and multiplying the mean amplitude A by a constant Ci for a square QAM constellation with 4m points, such that Sthi=A×Ci where m is a positive integer and i is a positive integer from 1 to (√4m-1)−1.
14 Citations
11 Claims
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1. A method on a communication receiver having a soft bit generator and a turbo decoder, the method for computing a threshold Sthi used in demodulating a quadrature amplitude modulated (QAM) signal received by the communication receiver to generate a plurality of soft bits per received symbol for input to the turbo decoder, the method including the steps of:
the soft bit generator; computing a mean amplitude A of the received symbols; multiplying the mean amplitude A by a constant Ci for a square QAM constellation with 4m points, such that
Sthi=A×
Ciwhere m is a positive integer and I is a positive integer from 1 to (√
{square root over (4m-1)})−
1;computing one or more of the soft bits from the threshold Sthi; and outputting the computed soft bits to the turbo decoder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A device within a communication receiver for computing a threshold Sthi used in demodulating a quadrature amplitude modulated (QAM) signal received by the communication receiver to generate a plurality of soft bits per received symbol for input to a turbo decoder, the device including:
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means for computing a mean amplitude A of the received symbols and multiplying the mean amplitude A by of the received symbols and multiplying the mean amplitude A by a constant Ci for a square QAM constellation with 4m points, such that
Sthi=A×
Ciwhere m is a positive integer and i is a positive integer from 1 to (√
{square root over (4m-1)})−
1;means for computing one or more of the soft bits from the threshold Sthi; and means for outputting the computed soft bits to the turbo decoder.
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11. A device within a communication receiver for generating soft bits per received symbol for input to a turbo decoder used in demodulating a quadrature amplitude modulated (QAM) signal received by the communication receiver, the device including:
-
means for computing a mean amplitude A of the received symbols and multiplying the mean amplitude A by a constant Ci for a square QAM constellation with 4m points, such that
Sthi=A×
Ciwhere m is a positive integer and i is a positive integer from 1 to (√
{square root over (4m-1)})−
1; andmeans for computing one or more of the soft bits from the threshold Sthi; and means for outputting the computed soft bits to the turbo decoder.
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Specification