Ma Ying, Shi Fangjing, Fan Yangyu
School of Electronic Information Engineering, Xi'an Technological University, Xi'an 710032, China.
School of Electronics and Information, Northwestern Polytechnical University, Xi'an 710129, China.
Micromachines (Basel). 2024 Apr 29;15(5):593. doi: 10.3390/mi15050593.
Combined in-band full duplex-multiple input multiple output (IBFD-MIMO) technology can significantly improve spectrum efficiency and data throughput, and has broad application prospects in communications, radar, the Internet of Things (IoT), and other fields. Targeting the self-interference (SI) issue in microwave photonic-based IBFD-MIMO communication systems, a microwave photonic self-interference cancellation (SIC) method applied to the narrowband 2 × 2 IBFD-MIMO communication system was proposed, simulated, and analyzed. An interleaver was used to construct a polarization multiplexing dual optical frequency comb with a frequency shifting effect, generating a dual-channel reference interference signal. The programmable spectrum processor was employed for filtering, attenuation, and phase-shifting operations, ensuring amplitude and phase matching to eliminate the two self-interference (SI) signals. The simulation results show that the single-frequency SIC depth exceeds 45.8 dB, and the narrowband SIC depth under 30 MHz bandwidth exceeds 32.7 dB. After SIC, the desired signal, employing a 4QAM modulation format, can be demodulated with an error vector magnitude (EVM) as low as 4.7%. Additionally, further channel expansion and system performance optimization are prospected.
带内全双工多输入多输出（IBFD-MIMO）技术能够显著提高频谱效率和数据吞吐量，在通信、雷达、物联网（IoT）等领域具有广阔的应用前景。针对基于微波光子的IBFD-MIMO通信系统中的自干扰（SI）问题，提出、仿真并分析了一种应用于窄带2×2 IBFD-MIMO通信系统的微波光子自干扰消除（SIC）方法。使用交织器构建具有频移效应的偏振复用双光频梳，产生双通道参考干扰信号。采用可编程频谱处理器进行滤波、衰减和相移操作，确保幅度和相位匹配以消除两个自干扰（SI）信号。仿真结果表明，单频SIC深度超过45.8 dB，30 MHz带宽下的窄带SIC深度超过32.7 dB。在进行SIC之后，采用4QAM调制格式的期望信号能够以低至4.7%的误差向量幅度（EVM）进行解调。此外，还展望了进一步的信道扩展和系统性能优化。
