收发同源设备中相位噪声对信号的影响分析

收发同源设备中信号经过下变频、A/D采样、数字信号处理、D/A恢复和上变频等流程,本文给出了相应的信号传输模型,并针对频标相位噪声对信号通过的影响进行了分析,基于上、下变频时刻频标相位噪声发生变化的分析,推导出了频标相噪对信号经过收发同源设备所产生的影响表达式,并得出结论:由于频标相噪的存在,使得信号通过收发同源设备后伪码速率和载波均被引入一个与频标频率变化率相关的因子,可视为引入了多普勒偏移量,并明确给出了该偏移量的表达式。该结论与普遍认为的收发同源可以完全抵消频标相噪的影响有较大区别,实验验证结果较好地吻合了理论分析的结论。

The Influence of Phase Noise to Signal Analysis Based on Transmitter and Receiver Homologous Equipment

Signals through transmit and receive homologous equipment, contains analog down conversion, A/D sampling, digital signal transfer and management, D/A recovering and analog up conversion. This paper presents the signal transmission model of transmitter and receiver homologous equipment, analysis the influence of phase noise on the signal. With respect to the frequency standard phase noise at down-convert moment, it already changed at the up-convert moment, so it concluded that: Signals through transmit and receive homologous equipment, RF carrier frequency and code rate are multiplied a constant factor because of frequency standard phase noise. It could be equivalent to the introduction of a Doppler offset shift, and its trend keeps consistent with frequency standard drift trend. The point is fundamentally different from the general conclusion , it considers the transmitter and receiver derived by the same frequency standard can fully offset the impact. Finally, by designing the special experimental program, this paper expects to verify the derivation of Doppler drift factor expression. Experimental test results show that Doppler shift test results are consistent with the formula derived result, and the frequency drift trend is in line with expectations. Therefore, the experimental test results show that the paper deduced conclusion is correctly.