Following is a made up example just to make the question clear:
In some cases when using an IC, it requires dual supply for its rails. And in that case such as above circuit, if we had single supply option such as 12V or any single supply instead of +/-6V, how should be the biasing done considering the circuit above?
So the system ground is MCU ground which is the laptop USB ground and in the circuit above the circuit ground and the system ground is same.
But if we use a single supply such as 12V supply, should we bias the negative rail and Vsig with Vcc/2? And how to couple it to MCU/system ground in that case?
Taking the example in the question and showing the modification for it would be better to see in the answer.