Digital Communications BER Performance in AWGN (BPSK and QPSK)

This chapter talks about Simulink utilizing binary Phase‐Shift Keying (BPSK) and quaternary Phase‐Shift Keying (QPSK) modulations. Frame‐based simulations execute faster and are often needed for matrix computations, where it is inconvenient to use sample‐based computation. Theoretical BPSK bit error rate (BER) performance in additive white Gaussian noise (AWGN) is well known. Simulation results using AWGN blocks and Gaussian noise generator blocks yield identical performance with properly chosen parameters. Use of a large sample size produces excellent agreement between theoretical and simulated BER performance. The AWGN block or a Gaussian noise block may be selected for either sample‐based or frame‐based simulation. The BPSK and QPSK simulations that were developed do not fully demonstrate the power of Simulink when the theoretical performance is known. A fixed point example is included where theoretical performance is difficult or impossible to obtain.