| 摘要 |
PURPOSE:To perform highly efficient high quality digital data transmission even under a weak propagation environment by combining a neural network and a viterbi decoder. CONSTITUTION:Reception demodulation signals pass through the forward direction calculation part 2-1 of the neural network 2 and are then inputted to the viterbi decoder 3. The output of the decoder 3 becomes decoded output and also the input of an encoder 4 and encoded again. The output of the encoder 4 becomes a reference signal for weight adjustment. In the meantime, a demodulation output value is supplied with time delay corresponding to the time delay of the decoder 3 by a delay line with a tap or a shift register 1 and becomes the input of the forward direction calculation part 2-2 of the network 2. A difference between the output of the calculator 2-2 and the decoder 4 is obtained and a differential signal is obtained. A weight is adjusted in a reverse direction calculation part 2-3 by the differential signal and signals reaching the viterbi decoder are calculated in the forward direction calculation part 2-1 by using the weight. The series of the operations is repeated. |
