Patent ID: 6590941
Filing Date: 2003-07-08
Classification: H04L

Abstract:
A method for estimating a carrier frequency error between received symbols (rk) and transmitted symbols (ck) in a packet transmission system, comprising the steps of:computing an error function (H(&Dgr;{circumflex over (f)})) for error values (&Dgr;{circumflex over (f)}) in an acquisition interval ([âˆ’fmax, +fmax]) and; deriving an estimation (&Dgr;{circumflex over (f)}0) of the carrier frequency error, the error function (H(&Dgr;{circumflex over (f)})) being defined for minimizing a magnitude which is representative of an average distance between the received phase-compensated symbols (râ€²k) and estimations (&ccirc;kej2&pgr;k&Dgr;{circumflex over (f)}) of the received symbols bearing frequency error estimation, obtained by varying the frequency error (&Dgr;{circumflex over (f)}) in the acquisition interval ([âˆ’fmax, +fmax]) for estimations of the transmitted symbol (&ccirc;k), the estimation (&Dgr;{circumflex over (f)}0) of the carrier frequency error corresponding to the minimum of a function F(&ccirc;k, &Dgr;{circumflex over (f)}) which depends on variables representing an estimation of the transmitted symbol &ccirc;k and an estimation of a normalized frequency error &Dgr;{circumflex over (f)} in the acquisition interval ([âˆ’fmax, +fmax]), respectively, defined by an equation of the type: F&af;(c^k,Î”&it;â€ƒ&it;f^)=&Sum;N-1k=0&it;&LeftBracketingBar;rkâ€²-c^k&it;&ee;j&it;â€ƒ&it;2&it;â€ƒ&it;Ï€&it;â€ƒ&it;k&it;â€ƒ&it;Î”&it;â€ƒ&it;f^&RightBracketingBar;2wherein:N represents the number of symbols used for computing the frequency error estimation (&Dgr;{circumflex over (f)}0), and râ€²k is a magnitude which is representative of the received symbols which are corrected in phase.