Anritsu BERTWave MP2100B, Руководство по эксплуатации, Страница: 174 / 382

Chapter 6 Measuring Bit Error
6-14
Received bit string 101010101010101010………101010101010101010101010….
Detected bit string 1010101010………101010101010
512 bits
64 bits
Figure 6.3-5 Pattern Detection Bit String when Frame Position is 1
The bit string used at pattern synchronization must occur at least once
within the programmable pattern.
In the example in Figure 6.3-5, when the Frame Position is 513, the bit
string between addresses 0x000040 and 0x000047 is used to detect
pattern synchronization. This 8-byte bit string appears once in the
programmable pattern. As a result, if these 64 bits and the received bit
string match, pattern synchronization is obtained.
If there is no bit string appearing at least once in the programmable
pattern, the bit string appearing the least number of times is set at
Frame Position.
+0 +1 +2 +3 +4 +5 +6 +7 +8 +9 +A +B +C +D +E +F
000000 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
000010 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
000020 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
000030 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F
000040 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F
000050 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F
000060 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F
000070 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F
000080 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
000090 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
0000A0 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
0000B0 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F
0000C0 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F
0000E0 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F
0000E0 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F
0000F0 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7E
Figure 6.3-6 Programmable Pattern Example 2
Sometimes pattern synchronization is obtained at the wrong position
depending on the user data pattern.