#Receive byte array from AXI traffic generator slave
payload = self.out0_util.sample_transaction()
#Note: this is a blocking call
formatString = "<"+str(len(payload.data)//2)+"h"
#"h" corresponds to a signed short which is 2 bytes in size. len() returns units of bytes.
upack = struct.unpack(formatString, payload.data)
#take the even numbered samples for real
rvec = upack[0:len(upack):2]
#take the odd numbered samples for imaginary
ivec = upack[1:len(upack):2]
#Reassemble into a complex numpy array
cVec = np.array(rvec) + 1j*np.array(ivec)