APPARATUS AND METHOD FOR SOFT-DECISION DEMODULATING IN NON-SQUARE QUADRATURE AMPLITUDE MODULATION
First Claim
1. An apparatus for soft-decision demodulating in non-square quadrature amplitude modulation, the apparatus comprising:
- a signal receiving unit receiving a quadrature amplitude modulation (QAM) modulated signal at an m modulation degree at a transmitting side;
a soft-decision bit calculating unit determining a soft-decision bit value by calculating log likelihood ratios (LLRs) for m bits of the received QAM modulated signal; and
a signal decoding unit restoring the received QAM modulated signal based on the determined soft-decision bit value,wherein the soft-decision bit calculating unit defines a log likelihood ratio calculation equation by approximating soft-decision boundary points of constellation points for m bits of non-square QAM having odd bits, respectively.
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Abstract
Disclosed are an apparatus and a method for soft-decision demodulating in non-square quadrature amplitude modulation. The apparatus includes: a signal receiving unit receiving a quadrature amplitude modulation (QAM) modulated signal at an m modulation degree at a transmitting side; a soft-decision bit calculating unit determining a soft-decision bit value by calculating log likelihood ratios (LLRs) for m bits of the received QAM modulated signal; and a signal decoding unit restoring the received QAM modulated signal based on the determined soft-decision bit value, in which the soft-decision bit calculating unit defines a log likelihood ratio calculation equation by approximating soft-decision boundary points of constellation points for m bits of non-square QAM having odd bits, respectively.
4 Citations
16 Claims
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1. An apparatus for soft-decision demodulating in non-square quadrature amplitude modulation, the apparatus comprising:
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a signal receiving unit receiving a quadrature amplitude modulation (QAM) modulated signal at an m modulation degree at a transmitting side; a soft-decision bit calculating unit determining a soft-decision bit value by calculating log likelihood ratios (LLRs) for m bits of the received QAM modulated signal; and a signal decoding unit restoring the received QAM modulated signal based on the determined soft-decision bit value, wherein the soft-decision bit calculating unit defines a log likelihood ratio calculation equation by approximating soft-decision boundary points of constellation points for m bits of non-square QAM having odd bits, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for soft-decision demodulating in non-square quadrature amplitude modulation, the method comprising:
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receiving a quadrature amplitude modulation (QAM) modulated signal at an m modulation degree at a transmitting side; defining a log likelihood ratio calculation equation by approximating soft-decision boundary points of constellation points for m bits of non-square QAM having odd bits, respectively; calculating log likelihood ratios (LLRs) for m bits of the received QAM modulated signal by using the defined log likelihood ratio calculation equation; determining soft-decision bit values based on the calculated log likelihood ratios; and restoring the received QAM modulated signal based on the determined soft-decision bit value. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification