An internal combustion engine includes a crankshaft and first and second cam actuated intake valves. The sample support further comprises at least one reaction chamber entered by an inflow channel branched off said at least one distributor channel, and a venting opening for each reaction chamber. A kth group is selected from the N groups in each OFDM symbol of a TTI, and a physical channel corresponding to a set of subcarriers indexed with predetermined values, included in the kth groups of the TTI is indexed with an ordered pair.