code: def wav2complex(filename):
      
      fs, x_LR_cols = ss.from_wav(filename)
      x = x_LR_cols[:,0] + 1j*x_LR_cols[:,1]
      return fs,x
docs: Return a complex signal vector from a wav file that was used to store
      the real (I) and imaginary (Q) values of a complex signal ndarray. 
      The rate is included as means of recalling the original signal sample 
      rate.
  
      fs,x = wav2complex(filename)
  
      Mark Wickert April 2014