An adaptive equalizer based on greatest constraint satisfaction criterion for coded communication systems

We propose an adaptive equalizer for coded communication systems, which adjusts filter taps using the gradient descent algorithm under the greatest constraint satisfaction (GCS) criterion. In particular, we derive the GCS equalizer for a low-density parity-check (LDPC)-coded multiple-input multiple-output (MIMO) system. We demonstrate by simulations that the GCS equalizer significantly outperforms the minimum mean square error (MMSE) equalizer under binary phase-shift keying (BPSK) modulation, and performs similar under quadrature phase-shift keying (QPSK) modulation.