“…Also, [13] introduced an efficient soft-decision algorithm (SDDA) and improved the Newton method for blind equalization of 4QAM. In [14], authors studied the space-time blind equalization (BE) of high-throughput QAM signals in MIMO systems and overcame the local convergence problem by multi-stage processing. Reference [15] proposed a doubleblind equalization technique based on rectangular quadrature amplitude modulation (RQAM), namely a rectangular contour algorithm and an improved rectangular contour algorithm.…”