If the signal transmitted at the transmitter is represented as,
x(t) = X_i(t)cos(2pifct) - X_q(t)sin(2pifct), where X_i(t) and
are inphase and quadrature components of the message signal.
then, at the receiver does the following equation correctly represent
signal after downcoversion to baseband like in a "RFX2400 + USRP’ set
inphase component of received signal = X_i(t)cos(2pif_offsett + phi )
quadrature component of received signal = X_q(t)sin(2pif_offsett +
where, ‘f_offset’ is the frequency offset present and ‘phi’ is the
Can someone suggest a good reference to direct conversion receivers?