| 摘要 |
A sixty-four state convolutional code known as the "Cole code" is disclosed and take systematic and non-systematic forms. The state variables of the Cole code are r(n-1), r(n-2), s(n-1), s(n-2), p(n-1), and x(n-1). In the four-to-five non-systematic form, four inputs p(n), q(n), r(n) and s(n) are used to generate five outputs y4(n), y3(n), y2(n), y1(n), and y0(n) according to: y4(n)=q(n); y3(n)=p(n)+r(n)r(n-1)+r(n-2)+r(n-1)s(n)+r(n-1)s(n-2); y2(n)=r(n-1)+s(n)+s(n-2); y1(n)=r(n)+r(n-1)r(n-2)+p(n-1)+p(n-2)+q(n-1); and y0(n)=s(n-1), where p(n-2)+q(n-1)=x(n-1). New state variables are obtained directly from the inputs and from the previous state variables, except for x(n) which is equals q(n)+p(n-1). In a three-to-four non-systematic implementation of the Cole code, q(n) is not input, y4 is not output, and q(n-1) is set equal to zero. In the four-to-five systematic form of the Cole code, the inputs y4, y3, y2, y1 are taken as outputs and are also used on conjunction with the convolutional encoder to generate a fifth output y0. With state variables x(n-1), p(n-1), r(n-1), r(n-2), s(n-1), s(n-2) relabled as w1, w2, w3, w4, w5, and w6, output y0 is taken as state variable w5. The state variables are updated according to: new w6=w5; new w5=y2+w3+w6; new w4=w3; new w3=y1+w3w4+w2+w1; new w2=y3+(new w3)w3+w4+w3(new w5)+w3w6; and new w1=y4+w2. In the three-to-four systematic Cole code, y4 is taken as zero.
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