Abstract: The interference components in a first composite signal are cancelled at baseband frequencies using a second composite signal. The first composite signal has a desired carrier and an interfering carrier. The desired carrier has a constant envelop and is angle modulated with baseband .phi..sub.1 (t). The interfering carrier has any type of modulation. The second composite signal has the interfering carrier. The first composite signal is angle demodulated. The first composite signal is also multiplied with the second composite signal. The product signal from the multiplier has a high and a low frequency component. The low frequency component is extracted from the product signal. The low frequency component is phase shifted by plus 90 degrees when the instantaneous frequency of the desired carrier is greater than the instantaneous frequency of the interfering carrier. When the instantaneous frequency relationship is reversed, the low frequency component is phase shifted by minus 90 degrees.