Methods and arrangements are provided where signaling of the modulation type by means of rotation of the training sequence is provided. For each modulation type, a set of rotation angles is chosen. These sets have no element in common. New training sequences are generated by rotating one original training sequence. The rotation angle that minimizes the PAPR of the transmit signal can be chosen. At the receiver side, knowing the original training sequence, the receiver estimates blindly the rotation angle among the known possible rotation angles. The estimated rotation angle in the receiver maps to a unique modulation type.