While I understand the problems trying to demodulate a DSB-SC signal using a direct conversion scheme, mostly the phasing issues arising from the fact that the sidebands are symettric and in quadrature, I still don't get why SSB receivers can't just pass band filter one of the sidebands and reinject the carrier, even if it's not frequency and phase synced with the original.
The scheme I see in most of receivers is an heterodyne approach: downconverting both sidebands, then filtering, and finally reinjecting the BFO. But, doesn't this present the same problems as reinjecting a carrier at an offset so as the desired sideband gets downconverted to audio frequency (after bandpass filtered it)?
Why do the other two major methods (phasing and weaver) need to have phasing syncronism while in heterodyne systems this is not required, but instead you have to downconvert twice?
Thanks and regards :)