I need to have output of qfunc as a handle function

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farah arabian 2017-12-5

评论： Walter Roberson 2017-12-6

all,

I need to have output of qfunc as a handle function but I face following error:

error:  """Error using qfunc 
The argument of the Q function must be a real array."""

so does anybody know how can I use handle function in qfunction??????

myf = @(ebn0)BER32APSK(c,M,ebn0)-p;

and inside of BER32APSK I would have:

fsum = fsum + qfunc(sqrt(((d2)*(log2(M))*ebn0)/2));

Walter Roberson 2017-12-5

One of d2 or log2(M) or ebn0 are not real-valued.

In particular check for the possibility that M is negative, as log of a negative number would give imaginary values.

Walter Roberson 2017-12-6

编辑：Walter Roberson 2017-12-6

I have gone through the formula in more detail. It has the following properties:

it is the sum of 442 terms of erfc(), then minus 1/10000000000
if x(1) == 1 exactly or x(2) == 1 exactly then there a few terms that have a limit of +1/40 as EBN0 goes to inf. As even one +1/40 is greater than -1/10000000000 in the sum, the sum is guaranteed positive for that case -- so there are no solutions if either x is exactly 1
if x(1) == x(2) exactly, then there is one term that has a limit of +1/40 as EBN0 goes to inf. As even one +1/40 is greater than -1/10000000000 in the sum, the sum is guaranteed positive for that case -- so there are no solutions if the x are exactly equal
in all other cases, x not 1 exactly and the x not exactly equal, the limit of all of the erfc() terms as EBN0 goes to inf is 0, so the limit as EBN0 goes to inf of the overall sum is -1/10000000000. As the terms start out positive for smaller EBN0 (30999999999/10000000000 for EBN0 = 0), the question involved becomes how far out do you have to go along EBN0 before the sum of those 442 terms happens to get small enough to just balance the -1/10000000000 . This is generally going to be a lot higher than the roughly 4 that you were expecting.

If you are expecting EBN0 solutions of roughly 4, then that would suggest that your equations may be wrong.

farah arabian 2017-12-6