[Discuss-gnuradio] gray code in D8PSK

[Arturo Rinaldi]

just  a simple question....why in D8PSK is the gray coding and decoding the following ?

# -----------------------
# Do Gray code
# -----------------------
# binary to gray coding -- constellation does Gray coding
binary_to_gray = {
    2 : range(2),
    4 : [0,1,3,2],
    8 : [0, 1, 3, 2, 7, 6, 4, 5]
    #8 : [0, 1, 3, 2, 6, 7, 5, 4]     <--------- why not this way in coding ?
    }

# gray to binary
gray_to_binary = {
    2 : range(2),
    4 : [0,1,3,2],
    8 : [0, 1, 3, 2, 6, 7, 5, 4]
    }


i was surprised to find a difference in bynary_to_gray and gray_to_binary in mapping the eight  symbols ! ! ! could you please explain me the reason ?


        thx in advance