2003 | OriginalPaper | Buchkapitel
Double-Sideband Suppressed-Carrier Amplitude Modulation and Coherent Detection
verfasst von : Steven A. Tretter
Erschienen in: Communication System Design Using DSP Algorithms
Verlag: Springer US
Enthalten in: Professional Book Archive
Aktivieren Sie unsere intelligente Suche um passende Fachinhalte oder Patente zu finden.
Wählen Sie Textabschnitte aus um mit Künstlicher Intelligenz passenden Patente zu finden. powered by
Markieren Sie Textabschnitte, um KI-gestützt weitere passende Inhalte zu finden. powered by
The standard AM modulated signal contains a sinusoidal component at the carrier frequency which does not convey any of the baseband message information. This component is included to create a positive envelope which allows demodulation by a simple, inexpensive envelope detector. From an information theory point of view, the power in the sinusoidal carrier component is wasted. In this experiment, you will see that it is not necessary to transmit the carrier component and that the baseband message can be recovered by a coherent demodulator. In fact, it can be shown that a coherent demodulator performs better than an envelope detector when the received signal is corrupted by additive noise. The type of modulation that will be studied in this chapter is called double-sideband suppressed-carrier amplitude modulation (DSBSC-AM). A close approximation to an ideal coherent demodulator called a Costas loop will be implemented.