Assume I have such modulated data which is, for example, $x=0.7+0.7i$. That modulated data is encapsulated in a vector as below:
where $c$ is any constant number, let’s say, for example: $c=0.7$ . My question is how can I detect if the received vector is $y_1$ or $y_2$ ? I mean is there a mathematical expression I can apply for detection?