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) signal modulated using m states of modulation 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, andwherein the soft-decision bit calculating unit calculates a log likelihood ratio for a third bit by using an equation given below;
1 Assignment
0 Petitions
Accused Products
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.
-
Citations
15 Claims
-
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) signal modulated using m states of modulation 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, and wherein the soft-decision bit calculating unit calculates a log likelihood ratio for a third bit by using an equation given below; - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for soft-decision demodulating in non-square quadrature amplitude modulation, the method comprising:
-
receiving a quadrature amplitude modulation (QAM) signal modulated using m states of modulation 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, wherein in the calculating of the log likelihood ratios (LLRs) for m bits, a log likelihood ratio for a third bit is calculated by using an equation given below; - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. 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) signal modulated using m states of modulation 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, and wherein the soft-decision bit calculating unit calculates a log likelihood ratio for a fourth bit by using an equation given below;
-
Specification