| 摘要 |
<p>A transmission system delays a carrier wave (20) and program audio (22) in the digital domain. The carrier wave and the program audio are converted to analog and the carrier wave is modulated by the program audio. The system includes a master oscillator (308) that generates a digital carrier wave. The digital carrier wave is transmitted to a delay stage (310) that delays the digital carrier wave by a certain delay value. The system further receives an analog or digital signal that is representative of programming. If an analog signal is received, the signal is transmitted to an analog-to-digital converter (302) where it is converted to digital audio. The digital audio is then transmitted to a delay stage (316) that delays the digital audio by the same delay value. The digital carrier wave and the digital audio are converted to an analog carrier wave and analog audio respectively. A modulator (322) modulates the analog carrier wave by the analog audio and sends the amplitude modulated carrier wave to a power amplifier (324). After power amplification, amplitude modulated carrier wave is broadcast by a conventional antenna (330). The delay of the carrier wave and the program audio are controlled by a processor (332). The processor may also control the output power of respective power amplifiers (324).</p> |
