Patent ID: 9008248
Filing Date: 2015-04-14
Classification: H04N

Abstract:
1. A method for demodulating a plurality of channels among a group of contiguous channels in a radio-frequency (RF) input signal, comprising: receiving the RF input signal comprising the group of contiguous channels and a mirror image of the group of contiguous channels; mixing the RF input signal with an in-phase local oscillator signal to produce a mixed in-phase signal and with a quadrature local oscillator signal to produce a mixed quadrature signal, wherein the group of contiguous channels and the mirror image of the group of contiguous channels are centered at baseband within the mixed in-phase signal and within the mixed quadrature signal; performing image rejection on the mixed in-phase and quadrature signals in the digital domain to recover the plurality of channels, wherein a first one of the plurality of channels originates from the group of contiguous channels and a second one of the plurality of channels originates from the mirror image of the group of contiguous channels, and wherein the step of performing comprises: recovering a first one of the plurality of channels by using the mixed in-phase signal as a reference to reject the second one of the plurality of channels in the mixed quadrature signal and using the mixed quadrature signal as a reference to reject the second one of the plurality of channels in the mixed in-phase signal; and recovering a second one of the plurality of channels by the using the mixed in-phase signal as a reference to reject the first one of the plurality of channels in the mixed quadrature signal and using the mixed quadrature signal as a reference to reject the first one of the plurality of channels in the mixed in-phase signal.