Application of Passband Decision Feedback Equalization in Two-Dimensional Data Communication Systems

We describe and experimentally evaluate a receiver structure for two-dimensional data communication systems based on passband decision feedback equalization and data-directed carrier recovery. The forward and feedback tap coefficients and the demodulator's carrier phase angle are adjusted adaptively; the carrier recovery and demodulation operation, as in the case of a linear equalization receiver, can compensate for rather severe frequency offset and phase jitter. Experimental results are reported of simulations of the receiver on voiceband telephone channels.