Circuit for demodulating digital signal undergoing different modulation schemes

Abstract

A circuit for demodulating a signal having a temporal mixture of different modulation schemes applied thereto includes a synchronization-word-detection unit which detects synchronization words included in the signal, and generates first and second position signals, based on the detected synchronization words, indicative of respective predetermined positions in the signal, a first selection unit which selects the first position signals during a first period, and selects the first position signals and the second position signals during a second period, and a carrier-reproduction unit which carries out frequency capturing during the first period by using the first position signals selected by the first selection unit, and carries out phase capturing during the second period by using the first position signals and the second position signals selected by the first selection unit, thereby reproducing a carrier.

Dependencies are inferred from the claim text.