Binary convolutional encoder of cable modem downstream system TCM encoder

摘要

The present invention relates to a binary convolutional encoder having characteristics of G1 (= 010101), G2 (= 011111) generation code, 16 states, and 1/2 bit rate in a cable modem downstream system TCM encoder.;The apparatus of the present invention is composed of four memories 51 to 54 connected in series and four exclusive logic operation units 55 to 58. Each of the memories 51 to 54 delays the input signal by one clock, The first and second exclusive logic operation units 55 and 56 perform an exclusive logic operation on the input signal of the encoder, the output of the second memory 52, and the output of the fourth memory 54 according to the G1 generation code. To output the Y1 signal, and the third and fourth exclusive logic calculators 57 and 58 perform an exclusive logic operation on the output of the first memory 51 and the output of the third memory 53, and again perform the second exclusive logic sum. An exclusive logical sum operation with the output of the calculating section 56 outputs the Y2 signal.;Therefore, the present invention does not design the exclusive logic operator for convolutional coding separately for the output signals Y1 and Y2, and uses the exclusive logic operator for Y1 again for the calculation of Y2, thereby making the binary convolutional encoder with only minimal components. There is an effect that can be designed efficiently.