A method for mapping a physical hybrid automatic repeat request indicator channel, PHICH, in groups of a plurality of PHICHs, to orthogonal frequency division multiplexing, OFDM, symbols, each OFDM symbol comprising of a plurality of resource element groups, each resource element group being comprised of four resource elements, the method comprising: • determining indexes of resource element groups in which the PHICH is transmitted, the method being characterised in that said indexes are determined according to the ratio n' l'i / n' 0 or n' l'i / n' 1 of the number n' l'i of available resource element groups in the OFDM symbol, having index l' i, in which the i th repetition of the PHICH of a PHICH group is transmitted, i being an integer of 0 to 2, and the number n' 0 or n' 1 of available resource element groups in the first OFDM symbol, having index 0, of a sub-frame or in the second OFDM symbol, having index 1, of a sub-frame, the PHICH being transmitted through one, two or three OFDM symbols, where the index l' i = 0, if the PHICH is transmitted through one OFDM symbol, where the index l' i = (└m'/2┘ + i + 1) mod 2, m' denoting an index of the PHICH group including the PHICH, if the PHICH is transmitted through two OFDM symbols, and where the index l' i = i, if the PHICH is transmitted through three OFDM symbols, available resource element groups being resource element groups which can be used for PHICH transmission in the respective OFDM symbol, and • mapping the PHICH to the OFDM symbols according to the determined indexes. each OFDM symbol comprising of a plurality of resource element groups, each resource element group being comprised of four resource elements, • determining indexes of resource element groups in which the PHICH is transmitted, the method being characterised in that said indexes are determined according to the ratio n' l'i / n' 0 or n' l'i / n' 1 of the number n' l'i of available resource element groups in the OFDM symbol, having index l' i, in which the i th repetition of the PHICH of a PHICH group is transmitted, i being an integer of 0 to 2, and the number n' 0 or n' 1 of available resource element groups in the first OFDM symbol, having index 0, of a sub-frame or in the second OFDM symbol, having index 1, of a sub-frame, the PHICH being transmitted through one, two or three OFDM symbols, where the index l' i = 0, if the PHICH is transmitted through one OFDM symbol, where the index l' i = (└m'/2┘ + i + 1) mod 2, m' denoting an index of the PHICH group including the PHICH, if the PHICH is transmitted through two OFDM symbols, and where the index l' i = i, if the PHICH is transmitted through three OFDM symbols, available resource element groups being resource element groups which can be used for PHICH transmission in the respective OFDM symbol, and the method being characterised in that said indexes are determined according to the ratio n' l'i / n' 0 or n' l'i / n' 1 of the number n' l'i of available resource element groups in the OFDM symbol, having index l' i, in which the i th repetition of the PHICH of a PHICH group is transmitted, i being an integer of 0 to 2, and the number n' 0 or n' 1 of available resource element groups in the first OFDM symbol, having index 0, of a sub-frame or in the second OFDM symbol, having index 1, of a sub-frame, the PHICH being transmitted through one, two or three OFDM symbols, where the index l' i = 0, if the PHICH is transmitted through one OFDM symbol, • mapping the PHICH to the OFDM symbols according to the determined indexes.