Modern communications systems tend to use complex signals instead of the real signals used in Problem 3. In this case, I used a software-defined radio with a digital signal processor (DSP) to create a received signal of the form: x(t) = xaudio(t)e/2nft In this case, I can send two audio signals at the same time on the same frequency channel. Xaudio (t) has the form: xaudio(t) = x(t) +jx(t) where x(t) and x2(t) are two separate wav files. This approach is much simpler than the one used in Problem 3, and it is commonly implemented in many digital signal processors (DSPS). I have stored the received signal x(t) in a file named "problem4.bin". This file is setup in the way that DSPs store complex data. Namely, the real and imaginary parts are each 32-bit floating point values that alternate as shown below: Please do the following: Real(x(1)) Imag(x(1)) Real(x(2)) Imag(x(2))