Sync word route

0

0

17x11 bytes

One

1

1

byte per

17x10 bytes

position

2

2

17x9 bytes

3

3

17x8 bytes

4

4

17x7 bytes

5

5

17x6 bytes

6

6

17x5 bytes

7

7

17x4 bytes

8

8

17x3 bytes

9

9

17x2 bytes

10

10

17x1

11

11

Figure 8 - DVB Conceptual Diagram of the Convolutional De-Interleaver Block

2.4.3.2 DSS

Before transmission, the data bytes are interleaved with each other in a cyclic pattern of thirteen. This ensures the

bytes are spaced out to avoid the possibility of a noise spike corrupting a group of consecutive message bytes.

Figure 9 below shows conceptually how the convolutional de-interleaving system works. On the PS20313, this

function is realized in the same Random Access Memory (RAM) as used for DVB, but utilizing a different

addressing algorithm.

Output

145

0

1

2

Input

12D

12D

12D

Figure 9 - DSS Conceptual Diagram of the Convolutional De-Interleaver Block

PLESSEY SEMICONDUCTORS LTD

TAMERTON ROAD | ROBOROUGH | PLYMOUTH | DEVON | PL6 7BQ

PS20313

12