本文首先利用5.8 GHz微波实际测量了辉光放电等离子体源电子密度和碰撞频率随时间的变化规律.然后搭建实验平台,测试了多种通信调制体制的信号经过该等离子体源后的误码率,实验发现二进制相移键控(BPSK)调制方式的信号在该时间变化的等离子体信道中通信误码率最小.最后加入磁场,实验测试了L波段(1.5 GHz)BPSK调制信号和S波段(2.5 GHz)正交相移键控(QPSK)信号在该磁化等离子体中的衰减、相移以及眼图和星座图的变化,通过与非磁化情况下对比发现,加入磁场后,信道的通信性能有所改善,误码率显著降低,可以有效地缓解时变等离子体引起的幅度和相位上的寄生调制效应.
In this paper the influences of the time-varying plasma and magnetized time-varying plasma on the communication performance are investigated. Using a 5.8 GHz microwave source, the electron density and collision frequency of the timevarying glow discharge plasma are measured. An experimental platform is set up to test the bit error rates(BERs) of a variety of the modulation signals after going though the time-varying plasma channel. The experimental results show that the binary phase shift keying(BPSK) modulation signal has a minimal communication BER. Meanwhile, the variations of L-band BPSK and S-band QPSK(quadrature phase shift keying) signal's eye diagram, and the constellation diagram,and the variation of energy after a magnetized plasma are observed. Compared with the un-magnetized situation, the magnetized plasma communication performance is greatly improved and the BER becomes much lower. The results prove that the magnetic field can effectively relieve the amplitude modulation and phase modulation caused by the plasma channel.