| 摘要 |
A modulation process for a digital transmission system having an error correcting code and determination of the number of bits to load on a transmission channel. The process judiciously associates a coder for introducing redundancy to the binary information, an interleaver for suppression the correlation to the encoded information and a labeling of the same based on a GRAY type coding in order to associate the said binary information with points of a constellation which is selected among a predetermined set of constellations. The process achieves a precise determination of the order and size of the constellation to utilize and, therefore, the computation of the bit loading as a function of the signal to noise ratio measured in reception and as a function of the bit error rate Pbit at the output of the receiver. The process is well adapted to the Multi Tone transmission system, and to the use of turbo codes.
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