In Double Sideband Reduced Carrier (DSBRC), the carrier signal is reduced to a fixed level that is below the carrier level for the modulator. The reduced carrier level is transmitted along with and serves as a reference frequency for the receiving equipment to use for demodulation. If the carrier level is reduced to a zero level, it is referred to as double sideband suppressed carrier( DSBSC).
Before demodulation, the carrier signal is added back on the receive side. The advantage of carrier reduction is the reduced transmit power. The method can also be used for single-sideband modulation.