A method performed in a preamble transmitter for transmitting a preamble sequence, the method comprising the steps of generating S11 a short sequence s(n), the short sequence having the same time duration as an OFDM symbol used for carrying data traffic in a radio access network of the preamble transmitter, constructing S12 a preamble sequence by concatenating a plurality of said short sequences in time, and transmitting S13 the constructed preamble sequence as a radio signal to a preamble receiver transmission and reception of a random access preamble signal.