16-11-2012, 12:07 PM
GOLD SEQUENCE GENERATION
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Theory:
Gold sequence is the special case of PN-sequence.The generation of the gold sequence is embedded in the gold theorem which states that g1(x) and g2(x) be preferred pair of primitive polynomial of degree n whose corresponding shift register generates maximal length sequence of period of 2n -1 and whose correlation function has magnitude less than equal to
2(n+1)/2+1 for odd
Or 2(n+1)/2+1 for even
Then shift register corresponding to product polynomial g1(x),g2(x) will generate 2n+1 different sequences.With each sequence having a period 2n-1 and cross correlation between any pair of such sequence satisfying the “preceding condition” it must satisfies the following properties.
Balance property:
The given sequence is said to satisfy balance property if the number of binary ones differs from zeroes by at most one digit in a period.
Run property:
The run is defined as the sequence of single type of binary digits.Its properties states that among the runs of ones and zeroes it is desirable that one half of each type are length one.
Correlation property:
If period of sequence is compared term by term with any cyclic shift of itself,it is best if the number of agreements differs from the number of disagreements.