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Shuffle Exchange Network and de Bruijn’s Graph. 010. 011. Shuffle Exchange graph. 000. 001. 110. 111. 100. 101. Merge exchange into a single node. 01. 1. 1. 00. 0. 0. 1. 1. 11. 0. 0. 10. De Bruijn Graph (label: shift left and add the label).
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Shuffle Exchange Network and de Bruijn’s Graph 010 011 Shuffle Exchange graph 000 001 110 111 100 101 Merge exchange into a single node 01 1 1 00 0 0 1 1 11 0 0 10 De Bruijn Graph (label: shift left and add the label)
Same Graph, Another labeling on edges 01 1 1 0 0 00 0 0 11 1 1 10 node x1x0 x0 (x1 label)
1 001 011 1 1 0 0 1 000 010 101 0 111 0 1 0 0 1 1 100 110 1 f is either 0 or 1 For 0: shift 1: complement f Note that each complete cycle of shift register corresponds to a HC ofde Bruijns Graph
0 0 . 001 000
Shift Register 0 0 1 001 011 000 010 101 111 100 110 x3 + x + 1 is irreducible 001 011 111 110 101 010 100 001 => DeBruijn sequence 001 011 000 010 101 111 100 110 x3 + x2 + 1 is irreducible 001 010 101 011 111 110 100 001 0 0 1
Shift Register x3 + x2 + x + 1 ? = (x2+1)(x+1) not irreducible 001 011 110 100 => degenerated cycle 0 0 1 001 011 000 010 101 111 100 110
For 4 bit 0001 0011 0111 1111 1110 1101 1010 0101 1011 0110 1100 1001 0010 0100 1000
Cycle decomposition based n 001 011 100 110 011 011 101 010
1 1 1 0 1 000 0 0 0 Conventional labeling 1 1 1 0 1 00 0 0 0
001 011 000 010 101 111 100 110