Redo the simple CDMA example of section 3.5, but now add random 'noise' to the transmitted signal

Question:

Redo the simple CDMA example of section 3.5, but now add random 'noise' to the transmitted signal (-2, 0, 0, -2, +2, 0). Add, for example, (1, -1, 0, 1, 0, -1). In this case, what can the receiver detect for sender A and B respectively? Now include the near/far problem. How does this complicate the situation? What would be possible countermeasures?