New receiver for joint blind equalization and carrier phase recovery of QAM signals

The paper introduces a new receiver for joint blind equalization and carrier phase recovery. The new receiver overcomes several disadvantages of systems in the literature by accomplishing modulus equalization and phase recovery in two independent operations. The proposed structure enables alternative and independent approaches to be taken for the design of the modulus and phase equalizer, respectively, and we propose two new algorithms for the modulus equalizer and the phase shifter. In particular, we propose a new constant modulus (CM) and modulus decision directed (MDD) hybrid algorithm for the equalizer. The CM and MDD both influence the adaptation of equalizer weight taps simultaneously. This enhances both the convergence rate and the steady state performance. The selection of step sizes for the modulus equalizer and the phase shifter is discussed. We compare the performance of our receiver with other previous receivers via computer simulations.