How to derive Q-factor from BER?

I have BER = 0.5 * Erfc(Q / sqrt(2))

How can I derive Q from this formula? I tried solve command, but get {Empty sym: 0-by-1} error?

Answer 1

[Priyanshu Mishra]

Hi Alina,

Since I do not have your code, I have written a small code. You may refer to it:

ber = 2*10^-4

syms ber Q

eqn = 0.5*erfc(Q/sqrt(2))

Q = vpasolve(eqn,Q)

For more information, visit documentation of vpasolve.

[Niki Erlando]

Hi Priyanshu,

I tried to follow your simple code, but somehow i kept getting the same answer eventhough i use a different value of BER ..

the answer is 2.254e+11184

Please help me