Blind equalization algorithms with automatic constellation phase recovery for dual-mode CAP-QAM reception

Some emerging broadband access standards require a receiver that can first blindly start up, then blindly distinguish between carrierless amplitude modulation/phase modulation (CAP) and quadrature amplitude modulation (QAM), and finally decode the signal. The "brute force" solution to this problem would be to implement CAP and QAM receivers in parallel. However, we propose a novel dual-mode receiver based on a single equalizer which accommodates both line codes, yielding significant computational savings. We describe the receiver architecture, blind start-up methods, and line code identification algorithms, as well as computer simulations and a laboratory experiment to verify the theoretical receiver behavior.