METHOD AND DEVICE FOR AN UPLINK TRANSMISSION DELAY ESTIMATION

A method for an uplink transmission delay estimation between a user equipment and a base station in a wireless communication network is disclosed.At least one random access preamble is received by the base station. The cyclic prefix is first removed (S402), an N-FFT is applied (S404) and the obtained sequence in the frequency domain is multiplied (S406) with a complex conjugate of a corresponding transmitted preamble sequence to obtain for each subcarrier k, a sequence of values Zk. A set of sums S[s] is computed (S408) from Zk. C candidate values Γ[c] are calculated (S414), each being a weighted linear combination of Γcs=Ssse−j2πlcss where 1[c,s] is a phase correcting factor. The candidate Copt among the C candidates with a smallest associated error calculated with respect to the sums S[s] is selected. A phase is determined responsive to the selected candidate. A delay is determined (S420) responsive to the determined phase.