| 摘要 |
A decoding system is provided with a modulating unit that modulates user data by using a modulation rule that disperses information for arbitrary bits of user data into a plurality of bits of a modulation pattern by modulating user data with the modulation pattern, and a regenerating unit that regenerates a signal, through which modulated user data has been transmitted along a transmission path, to generate a regenerated signal. The decoding system is further provided with a transmission path decoding unit that generates in accordance with the modulation pattern a signal, which takes into account the characteristics of a transmission path and is in accordance with the modulation pattern, as a generated signal, and calculates a distance between the regenerated signal and the generated signal within a section having a length determined, either on a constant or dynamic basis, in accordance with the bit length of the modulation pattern. The decoding system is also provided with a demodulating unit that calculates confidence level information for each bit of the user data, and estimates each bit of the user data on the basis of the calculated confidence level information. The transmission path decoding unit generates k generated signals (k is a positive integer), and calculates k respective distances between the regenerated signal and the respective generated signals in the section. The demodulating unit uses a formula (A) to calculate for each bit of the user data both the likelihood that the bit will be 1 as well as the likelihood that the bit will be 0, and uses a formula (B) to calculate the confidence level information. |
