Equalizer for quadrature carrier data transmission systems - appropiate derivation of correcting signals for errors between channels

摘要

The apparatus is as in 73.08476 and the equalizer, using filters, adders, decision circuits, not only corrects for amplitude and delays inter-symbol distortions but also corrects the transmission for cross-distortions between signals on two carriers with 90 deg. phase difference. The additions to the apparatus as in 73.08476 provide for adjustment of the phase at which samples are taken to feed error correction signals to equalizers (61) and (67). The outputs of two filters for the two carrier waves in quadrature are passed to the adder connected to a logic circuit which is used to maintain the correct phase relationship. The phase is determined by a special sampling process.