Patent attributes
A communication system in which probabilistic signal shaping and FEC coding are jointly applied using a partial amplitude-shaping scheme, under which bit-words representing binary labels of the transmitted amplitudes may have (i) a fixed number of amplitude most-significant bits (MSBs) generated using a shaping code and (ii) a fixed number of amplitude least-significant bits (LSBs) generated using an FEC code, e.g., without the shaping code being applied thereto. In various embodiments, the transmitted constellation symbols can carry, as sign bits, some original information bits and/or the parity bits generated by FEC-encoding some combination of the MSBs, the LSBs, and said some original information bits. Some embodiments are compatible with convolutional FEC codes, such as the trellis-coded modulation. Some embodiments can be used in communication systems relying on discrete multi-tone modulation, such as the systems providing DSL access over subscriber lines.
