Patent ID: 7313174

Claim:
A method for extracting a sequence of pilot symbols allowing to estimate the transfer function of a transmission channel, at least one radio communication device communicating through the channel with a remote station, the station regularly inserting a reference pattern in a signal transmitted to the radio communication device, said reference pattern having a structure in a time-frequency space defined at least by a spacing in time between two pilot symbols (N t ) and a spacing in frequency between two pilot symbols (N f ), wherein at least one feature of the structure of said reference pattern, said features comprising the value of said spacing in time between two pilot symbols (N t ) and/or of said spacing in frequency between two pilot symbols (N f ) is variable during transmission of said signal, the method comprising: receiving said signal; extracting a current reference pattern from said signal; analyzing said current reference pattern, to provide at least one characteristic of the transmission channel belonging to the group consisting of a maximum Doppler frequency and a maximum delay spread of the channel; and determining features of a next reference pattern, comprising the value of said spacing in time between two pilot symbols (N t ) and/or of said spacing in frequency between two pilot symbols (N f ), as a function of said at least one characteristic of the transmission channel.