An improved joint carrier recovery and adaptive equalization algorithm for high-order quadrature amplitude modulation (QAM) is proposed. It combines a dual-mode adaptive equalization algorithm and an optimal frequency/phase detection algorithm which operate in an optimal four-step sequence. Computer simulation and FPGA implementation demonstrate that this algorithm is robust even under low signal-to-noise ratio (SNR) and is especially suitable for high-order QAM receivers. The algorithm can acquire a carrier frequency offset up to 300 kHz at 256QAM over typical coaxial cable channels.