Communication - m Sequence                                 Home : www.sharetechnote.com

 

 

 

m Sequence (MLS : Maximum Length Sequence)

 

m-Sequence is a kind of (special kind of) LFSR sequence. So in order for you to understand m-sequence, first you need to understand the concept of LFSR sequence.

What is so special about m-sequence comparing to typical LFSR ? If you generate a sequence with LFSR, the output eventually repeats itself. But in most of the application, the purpose is to generate the longest possible non-repeating sequence with a given number of shift registers (Taps). m-Squence is a special type of LFSR which gives the longest non-repeating sequence for each give number of taps. The well-known m-sequence for various taps is shown in the following table.

 

No of Taps

Generator Polynomial

2

[2 1 0]

3

[3 2 0]

4

[4 3 0]

5

[5 3 0]

6

[6 5 0]

7

[7 6 0]

8

[8 6 5 4 0]

9

[9 5 0]

10

[10 7 0]

11

[11 9 0]

12

[12 11 8 6 0]

13

[13 12 10 9 0]

14

[14 13 8 4 0]

15

[15 14 0]

16

[16 15 13 4 0]

17

[17 14 0]

18

[18 11 0]

19

[19 18 17 14 0]

20

[20 17 0]

21

[21 19 0]

22

[22 21 0]

23

[23 18 0]

24

[24 23 22 17 0]

25

[25 22 0]

26

[26 25 24 20 0]

27

[27 26 25 22 0]

28

[28 25 0]

29

[29 27 0]

30

[30 29 28 7 0]

31

[31 28 0]

32

[32 31 30 10 0]

33

[33 20 0]

34

[34 15 14 1 0]

35

[35 2 0]

36

[36 11 0]

37

[37 12 10 2 0]

38

[38 6 5 1 0]

39

[39 8 0]

40

[40 5 4 3 0]

41

[41 3 0]

42

[42 23 22 1 0]

43

[43 6 4 3 0]

44

[44 6 5 2 0]

45

[45 4 3 1 0]

46

[46 21 10 1 0]

47

[47 14 0]

48

[48 28 27 1 0]

49

[49 9 0]

50

[50 4 3 2 0]

51

[51 6 3 1 0]

52

[52 3 0]

53

[53 6 2 1 0]