K指數型濾波器的關鍵點是這種濾波器可以保持在相同頻寬下，頻率響應會隨著一個名為k值的參數不同而改變且沒有符元間干擾。當頻寬的滾落率固定時，不同的k值會增加衰減的深度。對於匹配濾波器而言，能有效減少訊號的反射和多重路徑所引的失真與傳統所用的升餘弦濾波器相比。模擬結果顯示，在正交分頻多工系統中且不同多重路徑環境下，使用K指數型濾波器可得到較好的傳輸表現。特別是在調變一個符號內包含的位元數越多時，效果就越顯著，就算通道估測錯誤或是在都卜勒效應影響下，都可以有較好的傳輸品質。The key point of the K-exponential filter is that the frequency responses of the filter can vary with different specified parameter k without inter symbol interference (ISI) while keeping the same bandwidth. When the rolling factor αof the bandwidth is fixed, different value k will increase the depth of attenuation. For the application to the pulse shaping, it can reduce the signal reflection and multipath distortion that is compared with the traditional Raised cosine filter. Simulation results show that the K index filter obtains the better performance in OFDM systems with different multi-path environments. In particular, the effect is more significant if the modulation symbol contains more bits. Besides, it can provide a better transmission quality even if the channel estimation error or the influence of the Doppler effect is considered.
