I'm trying to modulate array of bits with GMSK modulation with BT=0.3 . What I'm doing is making O-QPSK modulation for given bits, then applying Gaussian filter on I and Q arrays and after that converting it to MSK modulation. Gaussian filter seems to be applied correctly. However the resulting MSK signal does not look similar to the example from book.
Here's my code to convert O-QPSK to MSK:
def msk_mod (i,q,samples_per_symbol): i_res=i q_res=q for k in range(0,int(samples_per_symbol/2)): i_res.append(0) q_res.insert(0,0) for k in range(0,len(i_res)): i_res[k]*=np.cos(np.pi*k/(samples_per_symbol)-np.pi/2) q_res[k]*=np.sin(np.pi*k/(samples_per_symbol)-np.pi/2) return i_res,q_res
but in the book I/Q data looks like that