K指數型濾波器是被設計用來在沒有符元間干擾情況下降低峰對平均功率比。關鍵點在於這種濾波器可以在同時保持相同頻寬下，其頻率響應隨著一個名為 的設計參數不同而跟著改變，這也是它的名稱由來。當頻寬的落滾率固定，則會存在一特定 值使得峰對平均功率比最小。模擬結果顯示出比起傳統所用的升餘弦濾波器，在正交分頻多功系統及交插分頻多重接取系統其最大峰對平均功率可分別降低0.25 dB及1 dB左右。此外，若是和同樣類型的多功能濾波器相比，它可在交插分頻多重接取系統擁有約略相當的成效，但在正交分頻多功系統卻有更好成效。 The K-exponential filter is designed for peak to average power ratio (PAPR) reduction without intersymbol interference (ISI). The key point is that the frequency responses of the filter which keeps the same bandwidth can vary with different designing parameter, the origin for the name. There is a minimum PAPR corresponding to an appropriate when roll-off factor α is fixed. The simulated result shows that the maximum PAPR reduction by the filters is about 0.25 dB in OFDM system and 1 dB in IFDMA system compared with the raised cosine filter. Besides, the K-exponential filter has almost equal performance in IFDMA system but better performance in OFDM system compared with the same kind of the versatile filter.
