Patent ID: 6539071
Filing Date: 2003-03-25
Classification: H04L

Abstract:
A packet transmission system comprising at least a terminal and a head station, the head station comprising means for receiving packets of data transmitted by said terminal with a frequency error &Dgr;f, and error estimation means for computing, on the basis of the received data, a discrete error function Z(&Dgr;{circumflex over (f)}) and for deriving an estimation &Dgr;{circumflex over (f)} of the frequency error corresponding to a maximum value of the error function Z(&Dgr;{circumflex over (f)}) for a given accuracy denoted (Acc), characterized in that said error correction means comprise:iteration means for effecting: a first iteration (it1) of the computation of the error function Z(&Dgr;{circumflex over (f)}) for 2N+1 error values comprised in a fixed standard range Â±&Dgr;fmax dependent on said terminal for deriving a first frequency error estimation &Dgr;{circumflex over (f)}(i), and successive iterations (iti+1), with i being a strictly positive iteration index, for values comprised between a current estimation &Dgr;{circumflex over (f)}(i) and a neighboring value for which the error function Z(&Dgr;{circumflex over (f)}) has the largest amplitude, means for comparing the result of each iteration (iti+1) with the current estimation &Dgr;{circumflex over (f)}(i) and for deriving a new estimation &Dgr;{circumflex over (f)}i+1) of the frequency error until a predetermined number of iterations, it, related to the accuracy (Acc) is obtained as defined by the relation: Acc=Î”&it;â€ƒ&it;fmaxNÃ—2It-1&CenterDot;