{HEAD ~ Carrier signals} can be directly demodulated to produce {TAIL ~ baseband inphase and quadrature signals}, or first downconverted to produce intermediate frequency signals 
directly demodulated to produce
{ HEAD ~ Carrier signals } can be directly demodulated to produce { TAIL ~ baseband inphase and quadrature signals } , or first downconverted to produce intermediate frequency signals
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH