Patent ID: 9270513
Filing Date: 2016-02-23
CPC Classification: H04L

Claim Text:
1. A decision-directed modified least mean square (DD-MLMS) method comprising: receiving an mQAM modulated data signal comprising a plurality of symbols; and equalizing the data signal using an adaptive finite impulse response (FIR) filter having multiple tap coefficients, wherein the tap coefficients are adaptively updated using a DD-MLMS algorithm and a cost function according to earlier symbol character information, wherein the filter tap coefficients updating equation is w(n)=w(n−1)+μe(n)x(n)*, where w(n) is the adaptive FIR filter, μ is a convergence parameter, e(n) is a complex error vector, x(n) is the received data signal, and [·]* stands for conjugation operation; wherein each of the symbols is determined as a decision symbol that is a shortest distance away from a respective mQAM constellation point, and the DD-MLMS algorithm tries to force the equalized signal to reside on the decision point, whereby carrier phase offset is blindly compensated.