A method performed by a network node in a wireless communication system, the method comprising: based on that a subcarrier spacing is a first subcarrier spacing of 15 kHz: configuring a first plurality of symbols related to the first subcarrier spacing such that i) a first cyclic prefix, CP, is assigned to an initial symbol in the first plurality of symbols and to every 7-th symbol after the initial symbol in the first plurality of symbols, and ii) a second CP is assigned to remaining symbols in the first plurality of symbols, wherein a length of the first CP is longer than a length of the second CP; based on that the subcarrier spacing is a second subcarrier spacing which is 2 m times the first subcarrier spacing: configuring a second plurality of symbols related to the second subcarrier spacing such that i) a third CP is assigned to an initial symbol in the second plurality of symbols and to every 7*2 m -th symbol after the initial symbol in the second plurality of symbols, and ii) a fourth CP is assigned to remaining symbols in the second plurality of symbols, wherein a length of the third CP is longer than a length of the fourth CP; and communicating with a wireless device by using the first plurality of symbols or the second plurality of symbols, based on whether the subcarrier spacing is the first subcarrier spacing or the second subcarrier spacing, wherein the m is a positive integer that represents a subcarrier spacing configuration, wherein a length between symbols with the first CP in the first plurality of symbols is same as a length between symbols with the third CP in the second plurality of symbols, and wherein a difference between the length of the first CP and the length of the second CP is same as a difference between the length of the third CP and the length of the fourth CP. based on that a subcarrier spacing is a first subcarrier spacing of 15 kHz: configuring a first plurality of symbols related to the first subcarrier spacing such that i) a first cyclic prefix, CP, is assigned to an initial symbol in the first plurality of symbols and to every 7-th symbol after the initial symbol in the first plurality of symbols, and ii) a second CP is assigned to remaining symbols in the first plurality of symbols, wherein a length of the first CP is longer than a length of the second CP; based on that the subcarrier spacing is a second subcarrier spacing which is 2 m times the first subcarrier spacing: configuring a second plurality of symbols related to the second subcarrier spacing such that i) a third CP is assigned to an initial symbol in the second plurality of symbols and to every 7*2 m -th symbol after the initial symbol in the second plurality of symbols, and ii) a fourth CP is assigned to remaining symbols in the second plurality of symbols, wherein a length of the third CP is longer than a length of the fourth CP; and communicating with a wireless device by using the first plurality of symbols or the second plurality of symbols, based on whether the subcarrier spacing is the first subcarrier spacing or the second subcarrier spacing, wherein the m is a positive integer that represents a subcarrier spacing configuration, wherein a length between symbols with the first CP in the first plurality of symbols is same as a length between symbols with the third CP in the second plurality of symbols, and wherein a difference between the length of the first CP and the length of the second CP is same as a difference between the length of the third CP and the length of the fourth CP. <EOS>