| 摘要 |
PURPOSE:To provide a digital multi-level demodulation method and multi-level demodulator in which a unique word undetection rate is reduced and frame synchronization is realized at a high speed with simple configuration. CONSTITUTION:Four kinds of reference data (UI1-UI3, UQ1-UQ3), (UIB1-UIB3, UQ1-UQ3), (UI1-UI3, UQB1-UQB3), (UIB1-UIB3, UQB1-UQB3) being combinations of logic inversion data (UIB1-UIB3) of I-channel bit patterns (UI1-UI3) of a known unique word and logic inversion data (UQB1-UQB3) of Q-channel bit patterns (UQ1-UQ3) are stored in registers (21a-21d). Demodulated I, Q channel data (I1-I3, Q1-Q3) and the reference data for the registers are EXNORed and a signal (ST) representing detection of the unique word is generated when coincidence with any of reference data is found out. |
