This paper describes an adaptive software aided technique for phase error reduction in digital carrier recovery (CR)for high-order Quadrature Amplitude Modulation (QAM). Simulations and analytical results illustrate a phase error variance improvement of at least 30dB compared to conventional CR, leading to more than 3dB processing gain enhancement for high-order QAM, using the simple 4^th power phase estimation technique. The new technique can be employed to improve the performance of any CR loop, at the cost of slight complexity overhead independent of the modulation order.