| 摘要 |
PROBLEM TO BE SOLVED: To encode a digital signal by using a low dimensional convolutional encoder. SOLUTION: An output of a modulator 15 is converted into N-dimensional symbol with a mapping rule or J pieces of P-dimensional signal points. An encoder 13 outputs what is converted from them to the modulator 15. The modulator 15 includes an interleaver which reconstructs the sequence of signal points that make continuous signal points generated by the encoder 13 not to continuously appear on a television channel. To include the interleaver secures the optimum performance of convolutional decoder. That is, the modulator 14 generates N-dimensional symbol sequences as a digital signal function by using an N'-dimensional convolutional encoder in a trellis coding modulator between N-dimensional symbol intervals more than one time in order to encode a digital signal. With this, the trellis coding modulator generates higher order output that what is usually expected from a low dimensional convolution encoder. |
