The receiver locally regenerates the subcarrier by doubling a special 19 kHz pilot tone, but in other DSB-SC systems, the carrier may be regenerated directly from the sidebands by a Costas loop or squaring loop.
The receiver locally regenerates the subcarrier by. The receiver locally is doubling a special 19 kHz pilot tone. The carrier may be regenerated directly from the sidebands by a Costas loop or squaring loop. This was in other DSB-SC systems.