Limitations on the subcarrier frequency-to-symbol rate ratio

The residual-carrier tracking performance for PCM/PSK/PM/NRZ for square-wave and sine-wave subcarriers is evaluated as a function of the symbol SNR degradation. Explicitly, the RF residual carrier tracking performance is defined in terms of the subcarrier-to-symbol rate ratio, n. The upper and lower bound values for n are derived, and used to determine the minimum required bandwidth for maximum residual-carrier tracking performance. The analytical results obtained from the mathematical models are validated by computer simulation.<>