5th unit[1].pdf

download 5th unit[1].pdf

of 7

Transcript of 5th unit[1].pdf

  • 7/28/2019 5th unit[1].pdf

    1/7

    UNIT 5Problems

    1. The generator matrix (G) of a particular (7, 4) linear block code is given by G

    = 1 1 1

    1 0 1 0 1 1 1 1 0

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    i) Find the parity check matrix (H).ii) List all the code vectors.iii) compute the syndrome for the received vector 1101101. Is this a valid

    code.(16)

    Solution :

    i) List all the code vectors.Code words.X = DG = [0000]

    = [0000]1 1 1 1 0 1 0 1 1 1 1 0

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    = [0000] = 0000000

    = [0001]

    = 1100001

    = [0010] = 0110010 = [0011] = 1010011 = [0100] = 1010100 = [0101] = 1100110 = [0110] = 1100001 = [0111] = 0000111

    = [1000]

    = 1111000

    = [1001] = 0011001 = [1010] = 1001010 = [1011] = 0101011 = [1100] = 0101100 = [1101] = 1001101

  • 7/28/2019 5th unit[1].pdf

    2/7

    = [1110] = 0011110 = [1111] = 1111111

    = 0000000,

    = 1100001,

    = 0110010,

    = 1010011,

    = 1010100,

    = 0110101, = 1100110, = 0000111, = 1111000,= 0011001, = 1001010, = 0101011, = 0101100,= 1001101, = 0011110, = 1111111

    ii) The parity check matrix (P).

    =

    1 1 1 1 0 1 0 1 1

    1 1 0

    1 0 0

    0 1 0

    0 0 1

    0

    0

    0

    0 0 0 1

    =

    1 1 1 1 0 1 0 1 1 1 1 0

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    Given n = 7, K = 4 where

    = 1 1 1

    1 0 1

    0 1 11 1 0and

    = 1 0 00 1 00 0 1

    0

    0

    00 0 0 1

    thus = [ ] = [ ]

    = 1 0 00 1 00 0 1

    = 1 1 01 0 1

    1 1 1

    1

    1

    0

  • 7/28/2019 5th unit[1].pdf

    3/7

    = 1 0 00 1 00 0 1

    1 1 0

    1 0 1

    1 1 1

    1

    1

    0

    iii) Error detection:Code vector received r = 1101101

    The combination for error detection r.HT

    = 0. = 0[1101101] =

    1 0 0

    0 1 0

    0 0 1

    1 1 1

    1 0 1

    0 1 1

    1 1 0

    = [0 1 0]

    . 0The code vector is not valid2. The generator matrix (G) of a particular (7, 4) linear block code is given by G

    = 1 1 1 1 0 1 1 1 1 1 1 1

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    i) Find the parity check matrix (P).ii) List all the code vectors.iii) compute the syndrome for the received vector 1101101. Is this a valid

    code.(16)

    Solution :

    i) List all the code vectors.

    Code words.X = DG

    = [0000]

    = [0000]1 1 1 1 0 1 1 1 1 1 1 1

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    = [0000] = 0000000 = [0001] = 1110001 = [0010] = 1110010

  • 7/28/2019 5th unit[1].pdf

    4/7

    = [0011] = 0000011 = [0100] = 1010100 = [0101] = 0100101 = [0110] = 0100110

    = [0111]

    = 1010111

    = [1000] = 1111000 = [1001] = 0001001 = [1010] = 0001010 = [1011] = 1111011 = [1100] = 0101100 = [1101] = 1011101 = [1110] = 1011110 = [1111] = 1111111 = 0000000, = 1110001, = 1110010, = 0000011, = 1010100,

    = 0100101,

    = 0100110,

    = 1010111,

    = 1111000,

    = 0001001, = 0001010, = 1111011, = 0101100,= 1011101, = 1011110, = 1111111ii) The parity check matrix (P).

    = 1 1 1 1 0 1 1 1 1 1 1 1

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    = 1 1 1

    1 0 1 1 1 1 1 1 1

    1 0 0

    0 1 00 0 1

    0

    00

    0 0 0 1

    Given n = 7, K = 4 where

    = 1 1 11 0 11 1 11 1 1

    and

    = 1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    thus = [ ] = [ ]

  • 7/28/2019 5th unit[1].pdf

    5/7

    = 1 0 00 1 00 0 1

    = 1 1 1

    1 0 1

    1 1 11 1 1

    = 1 1 11 0 1

    1 1 1

    1

    1

    1

    = 1 0 00 1 0

    0 0 1

    1 1 1

    1 0 1

    1 1 1

    1

    1

    1

    iii) Error detection:Code vector received r = 1101101The combination for error detection r.HT = 0. = 0

    [1101101] =

    1 0 0

    0 1 0

    0 0 1

    1 1 1

    1 0 1

    1 1 11 1 1

    = [0 1 1]. 0The code vector is not valid

    3. The generator matrix (G) of a particular (7, 4) linear block code is given by G

    =

    1 1 1 1 0 1

    1 1 1 1 0 1 1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    i) Find the parity check matrix (P).ii) List all the code vectors.iii) compute the syndrome for the received vector 1101101. Is this a valid

    code.

  • 7/28/2019 5th unit[1].pdf

    6/7

    Solution :

    i) List all the code vectors. - 8marksCode words.X = DG

    = [0000] = [0000]1 1 1 1 0 1 1 1 1 1 0 1

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    = [0000] = 0000000 = [0001] = 1010001 = [0010] = 1110010 = [0011] = 0100011

    = [0100]

    = 1010100

    = [0101]

    = 0000101

    = [0110] = 0100110 = [0111] = 1110111 = [1000] = 1111000 = [1001] = 0101001 = [1010] = 0001010 = [1011] = 1011011 = [1100] = 0101100 = [1101] = 1111101 = [1110] = 1011110

    = [1111]

    = 0001111

    = 0000000, = 1010001, = 1110010, = 0100011, = 1010100,= 0000101, = 0100110, = 1110111, = 1111000,= 0101001, = 0001010, = 1011011, = 0101100,= 1111101, = 1011110, = 0001111

    ii) The parity check matrix (P). - 4marks

    = 1 1 1 1 0 1 1 1 1 1 0 1

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    = 1 1 1 1 0 1 1 1 1 1 0 1

    1 0 0

    0 1 0

    0 0 1

    0

    0

    00 0 0 1

    Given n = 7, K = 4 where

  • 7/28/2019 5th unit[1].pdf

    7/7

    = 1 1 11 0 11 1 11 0 1

    and

    = 1 0 00 1 00 0 1

    00

    00 0 0 1

    thus = [ ] = [ ]

    = 1 0 00 1 00 0 1

    = 1 1 1

    1 0 1

    1 1 11 0 1

    = 1 1 11 0 11 1 1

    1

    0

    1

    =

    1 0 0

    0 1 0

    0 0 1 1 1 1

    1 0 1

    1 1 1

    1

    0

    1

    iii) Error detection: `- 4marksCode vector received r = 1101101The combination for error detection r.HT = 0. = 0

    [1101101] =

    1 0 0

    0 1 0

    0 0 1

    1 1 1

    1 0 1

    1 1 1

    1 0 1

    = [0 0 1]. 0The code vector is not valid