降低誤警報率之移頻FMCW訊號波型設計

Shifted Frequency FMCW Signal Design with Reduced False Alarm Rate

鍾日龍(Rih-Lung Chung) ； 簡康祐(Kang-You Chien) ； 王厚元(Hou-Yuan Wang) ； 許智捷(Chi-Chieh Hsiu)

《先進工程學刊》 10卷2期 (2015/04) Pp. 79-86

摘要

在本論文，我們採用波形設計法，藉由給定傳送波形不同的起始頻率，降低調頻連續波雷達波形的相關性，以解決共頻帶干擾問題。首先，我們藉由理論推導，得知若在頻帶干擾下二雷達傳送波形之初始頻率差大於二倍的低通濾波器頻寬，則二波形之相關性可大幅降低，並且誤拍頻可成功地移出低通濾波器頻寬外。接著，我們也推導出具速度下的拍頻，並得知速度的因子在設計低相關性的傳送波形可忽略不計。最後，我們用電腦模擬來驗證我們所提出的方法可以有效地降低誤警報率。

關鍵字

調頻連續波 ； 波形設計 ； 相關性 ； 頻帶干擾 ； 拍頻

並列摘要

In this paper, we adopt waveform design in which two transmitted frequency modulation continuous waves (FMCW) have different initial frequencies to tackle the common-band interference (CBI) problem. First, we design the two radar's sweeping waveforms with low correlation for removing false beat frequency. It is proved by the theoretical derivation that the false beat frequencies can be removed from radar's low pass filter (LPF) if the sweeping waveforms have different initial frequencies of the difference greater than two times of LPF's bandwidth. Next, by taking into account the factor of moving speed, we also derive the beat frequency with velocity. It is shown that the velocity can be almost ignored in the low-correlation criterion of waveform design. Finally, we employ computer simulation to demonstrate our proposed method can reduce false-alarm rates effectively.

並列關鍵字

FMCW ； waveform design ； correlation ； common-band interference (CBI) ； beat frequency