光子型远程分布式微波信号接收码元速率估计

Symbol rate estimation for remote distributed microwave signal reception using photonic technique

基于光子学技术,设计了一种针对远程分布式微波信号接收的码元速率估计方案。首先,远程终端将接收的微波信号经电光调制器对连续激光源进行载波抑制双边带调制,生成携带微波信号的两个光边带信号;此光信号经光纤链路传输至中心站在光域滤除其中一个边带;其次,进行光电探测,通过分析电频谱的谐波实现微波信号码元速率估计。针对此方案,搭建仿真及实验系统装置:仿真成功地从60 GHz微波信号中提取出0.8 GBaud和6 GBaud的二进制伪随机码(PRBS)信号码元速率、从25 GHz微波信号中提取出3GBaud的PRBS码元速率;实验成功地从25 GHz的微波信号中提取出3 GBaud和5 GBaud的PRBS码元速率。

Based on photonic technique, an approach to the symbol rate estimation of the remote distributed microwave sig- nal reception is proposed and demonstrated experimentally. Firstly, the received microwave signal is applied to modulating the light wave under the carrier-suppressed double sideband （CS-DSB） modulation in the remote terminal, generating two optical sideband signals carrying the microwave signal. Then the two sidebands are transmitted to the central station through optical fiber links, and one of them is filtered out in the optical domain. After the photoelectric detection （PD）, the microwave signal symbol rate can be obtained by analyzing the spectrum of the electrical signals. The proposed approach is verified via both simulations and experiments. In the simulations, the symbol rate of 0.8 GBaud or 6 GBaud is successfully extracted for pseudo-random binary signal （PRBS） with the carrier frequency at 60 GHz. At the same time, the symbol rate of 3 GBaud is extracted for PRBS signals with 25 GHz carrier frequency. In the experiments, the symbol rate at 3 GBaud or 5 GBaud is achieved when the carrier frequency is 25 GHz. The proposed approach has the advantages such as wide instantaneous bandwidth, low loss for remote transmission, availability for distributed monitoring, and strong immunity to electromagnetic interference, which would play an important role for the microwave signal analysis and estimation.