在多頻帶的帶通採樣下降低抖動量的影響

Abstract

本論文中，我們提出了兩種方法去做補償和降低抖動量的影響。第一種方法，我們使用導頻信號的幫助去估出抖動量的大小，用估出來的抖動量再去補償，以至於降低抖動量的影響。再結合第二種方法，降低剩餘的抖動量，這邊我們使用了多頻帶的帶通採樣，以至於有多個取樣數可以降低抖動的影響去取平均。除此之外，我們還分析了理論值和模擬值，指出系統性能的準確度，也分析出那些參數會影響系統的性能，我們也和一些參考文獻上所找到的方法作為比較，證明使用我們所提出的方法成果會比較好。

Multiband bandpass sampling techniques have been widely used in Soft Define Radio (SDR) systems. The performance of systems using bandpass sampling is highly affected by jitter effects. This work investigates jitter effects for multiband bandpass sampling systems, and proposes a receiver that applies a two-stage method for combating the jitter effect. At the first stage, a maximum likelihood pilot-aided algorithm is used to estimate and compensate the dominated jitter. Then, at the second stage, we exploit the oversampled property of the received signal and propose a decimate-and-average scheme to further mitigate the residual jitter effect. Moreover, the performance of the proposed system is analyzed and Cramer-Rao Lower Bounds are derived. Simulation results corroborate the theoretical results, and show that the proposed schemes can significantly reduce the jitter effect.