A simplified architecture is disclosed for ADC conversion of received
in-phase I and quadrature Q signals. Circuit area is substantially
reduced by sharing a single ADC to convert both signals, switching the
ADC input alternately between the i and q signals. In an embodiment, the
ADC is clocked at an increased sample rate, and the digital output
signals are aligned to compensate for the phase difference resulting from
the implementation of a single ADC. Aligning includes delaying one of the
digital signals, and interpolating the other one of the digital signals
in a low pass filter so as to compensate for the phase difference
introduced by the sampling during the first and second time intervals.
The first and second time intervals are equal to a predetermined ADC
sample period corresponding to a sample clock cycle. Delaying the first
digital signal includes a delay of 1/2 clock cycle.