Single Channel Simulcast
Encyclopedia
Single/Multi Channel Simulcast is the simultaneous transmission of an amplitude modulated
and Digital Radio Mondiale
(DRM) in the same (SingleChannel Simulcast - SCS) or a neighbouring channel (MultiChannel Simulcast - MCS).
To produce this SCS multiplex
signal, the initial carrier is modulated by the DRM signal using quadrature phase modulation. This FM
signal is then modulated as if it were a normal AM
carrier, thus producing two modes on the single signal.
Clearly the advantage of this is that both DRM and analogue radios can receive a signal they can discriminate and demodulate, with little disadvantage to either mode.
It can, however, decrease DRM range, and the phase changes in the carrier can induce local oscillator interference in the AM receiver, which will show as white noise.
Amplitude modulation
Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...
and Digital Radio Mondiale
Digital Radio Mondiale
Digital Radio Mondiale is a set of digital audio broadcasting technologies designed to work over the bands currently used for AM broadcasting, particularly shortwave...
(DRM) in the same (SingleChannel Simulcast - SCS) or a neighbouring channel (MultiChannel Simulcast - MCS).
To produce this SCS multiplex
Multiplexing
The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...
signal, the initial carrier is modulated by the DRM signal using quadrature phase modulation. This FM
FM broadcasting
FM broadcasting is a broadcasting technology pioneered by Edwin Howard Armstrong which uses frequency modulation to provide high-fidelity sound over broadcast radio. The term "FM band" describes the "frequency band in which FM is used for broadcasting"...
signal is then modulated as if it were a normal AM
Amplitude modulation
Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...
carrier, thus producing two modes on the single signal.
Clearly the advantage of this is that both DRM and analogue radios can receive a signal they can discriminate and demodulate, with little disadvantage to either mode.
It can, however, decrease DRM range, and the phase changes in the carrier can induce local oscillator interference in the AM receiver, which will show as white noise.