Results¶

When the communication between the USRPs was established, the transmitted constellation below was obtained.

Figure 2.2 Transmitted Constellation

Using an IQ sampling of 500k, obtaining a symbol rate of 62500 symbols/sec, without any noise, the received constellation is shown below. The BER in this case is, evidently, 0.

Figure 2.2 Received Constellation without AWGN

The constellation on figure 11 was obtained when adding AWGN, for a target $E_b/N_0$ (received $E_b/N_0$) of 5.The constellation will vary as the values of $E_b/N_0$ vary, making it either noisier, or making it resemble a noiseless channel.

Figure 2.3 Noisy Constellation

With AWGN, the $BER$ is calculated, then compared to the theoretical one, obtaining a $BER$ vs $E_b/N_0$ graph like the one depicted below in figure 12. It can be seen that the simulated $BER$ follows, as expected, the same behavior as the theoretical $BER$.

Figure 2.3 BER vs Eb/No without coding