2 Practical seminars

2.1 Cyclic code combination synthesis

Objective: To learn the separable code combination of the cyclic code construction algorithm.

Task to the practical seminar:

1. To learn items 1.2.1 – 1.2.2 of this teaching manual.

2. To composite the information block, which consists of student’s surname and name initials.

3. To calculate key parameters of a cyclic code according to the variant.

4. To synthesise a code combination of the CC according to the calculated parameters.

5. To check up correctness of reception code combination in the binary form.

Initial data:

Parameter	Penultimate figure of number of the credit book
	1	2	3	4		5	6	7	8	9	0
рer	210-3	510-4	110-3	710-5		3,710-3	410-4	210-5	2,510-4	110-4	3,510-4
d0	3	4	3	4		3	4	3	4	3	4
Parameter	Last figure of number of the credit book
	1	2	3		4	5	6	7	8	9	0
	0,55	0,6	0,4		0,65	0,45	0,7	0,47	0,62	0,5	0,52
Рun er (1*10-6)	1,0	0,5	0,7		0,8	0,9	0,8	0,7	0,6	0,5	0,4

2.1.1 Compositing of the information block

For compositing it is necessary to use a fragment of the code table of primary ASCII code which is presented in fig. 2.1. The senior bits are read out from first four lines, and younger – from first four columns corresponding to a site of the letter.

								0			0
								0			1
								1			0
								1			0
Numbers of categories								English alphabet letters
b8	b7	b6	b5	b4	b3	b2	b1
8	7	6	5	4	3	2	1
				0	0	0	0				P
				0	0	0	1	A			Q
				0	0	1	0	B			R
				0	0	1	1	C			S
				0	1	0	0	D			T
				0	1	0	1	E			U
				0	1	1	0	F			V
				0	1	1	1	G			W
				1	0	0	0	H			X
				1	0	0	1	I			Y
				1	0	1	0	J			Z
				1	0	1	1	K
				1	1	0	0	L
				1	1	0	1	M
				1	1	1	0	N
				1	1	1	1	O

Figure 2.1 – ASCII Code. A fragment of the English alphabet

For example, Sidorov Ivan's initials are:

S ® 0100 0011;

I ® 0011 1001.