| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent processing delay by determining a logarithmic likelihood ratio fast and efficiently. <P>SOLUTION: A demodulating unit 220 outputs to a soft decision information calculating unit 250 an in-phase (I) component and a quadrature (Q) component of each received symbol included in a received signal as demodulation data. A reference amplitude calculating unit 240 calculates a reference amplitude from a coefficient corresponding to a channel estimate and a modulation scheme and outputs the reference amplitude obtained to the soft decision information calculating unit 250. The soft decision information calculating unit 250 calculates an LLR by bit from the I component and the Q component of each received symbol and the reference amplitude. At this point, the soft decision information calculating unit 250 calculates the LLR for each bit by performing arithmetic operation including arithmetic operation of an absolute value for each bit. Namely, the soft decision information calculating unit 250 uniformly calculates the LLR using the same operation expression for the same bit, regardless of a region, to which the received symbol belongs, on an IQ plane. <P>COPYRIGHT: (C)2011,JPO&INPIT |
