Patent ID: 7894330

Claim:
A method for mapping a physical hybrid automatic repeat request indicator channel (PHICH) to orthogonal frequency division multiplexing (OFDM) symbols using resource elements as units, the method comprising: determining indexes of resource element groups (REGs) in which repetitive patterns of the PHICH are transmitted; and mapping the PHICH to the OFDM symbols according to the determined indexes, wherein an index ( n i ) of the REG in an OFDM symbol of index l′ i is determined by using one of the following equation 1 or 2: n _ i = { ⁢ ( ⌊ ( N ID cell · n l i ′ ′ / n 0 ′ ) ⌋ + m ′ ) ⁢ mod ⁢ ⁢ n l i ′ ′ i = 0 ⁢ ( ⌊ ( N ID cell · n l i ′ ′ / n 0 ′ ) ⌋ + m ′ + ⌊ n l i ′ ′ / 3 ⌋ ) ⁢ mod ⁢ ⁢ n l i ′ ′ i = 1 ⁢ ( ⌊ ( N ID cell · n l i ′ ′ / n 0 ′ ) ⌋ + m ′ + ⌊ 2 ⁢ ⁢ n l i ′ ′ / 3 ⌋ ) ⁢ mod ⁢ ⁢ n l i ′ ′ i = 2 equation ⁢ ⁢ 1 where N ID cell denotes a cell ID, n′ l′ i denotes the number of available resource element groups in the OFDM symbol of index l′ i , n′ 0 denotes the number of available resource element groups in an OFDM symbol of index 0, and m′ denotes an index of a PHICH group, n _ i = { ⁢ ( ⌊ ( N ID cell · n l i ′ ′ / n 0 ′ ) ⌋ + m ′ ) ⁢ mod ⁢ ⁢ n l i ′ ′ i = 0 ⁢ ( ⌊ ( N ID cell · n l i ′ ′ / n 0 ′ ) ⌋ + m ′ + ⌊ n l i ′ ′ / 3 ⌋ ) ⁢ mod ⁢ ⁢ n l i ′ ′ i = 1 ⁢ ( ⌊ ( N ID cell · n l i ′ ′ / n 0 ′ ) ⌋ + m ′ + ⌊ 2 ⁢ ⁢ n l i ′ ′ / 3 ⌋ ) ⁢ mod ⁢ ⁢ n l i ′ ′ i = 2 equation ⁢ ⁢ 2 where N ID cell denotes a cell ID, n′ l′ i denotes the number of available resource element groups in the OFDM symbol of index l′ i , n′ 1 denotes the number of available resource element groups in an OFDM symbol of index 1, and m′ denotes an index of a PHICH group.