【摘要】 针对同时存在恶意干扰与非法窃听的通信环境，提出一种协作干扰(cooperative jamming, CJ)掩护的保密通信架构，收发信机之间采用跳频技术躲避恶意干扰，并采用协作干扰技术阻塞非法窃听。但该架构的通信带宽较大，会在收发频率振荡器中引起显著的同相和正交(in-phase and quadrature, IQ)通道失衡。鉴于此，对收发IQ通道失衡引起的信号失真进行数学建模，给出接收机处信干噪比的数学表达式，并给出干扰抑制比的闭合表达式。仿真结果表明，收发IQ通道失衡引起的信号失真的功率远大于热噪声功率。随着收发IQ通道失衡加剧，所提架构的信干噪比和干扰抑制比性能均会急剧下降，当幅度和相位失衡分别达到0.95和π/50时，信干噪比和干扰抑制比均损失了47 dB。更多还原

【Abstract】 A CJ(cooperative jamming) masked secure communication architecture was proposed for confidential communications when malicious interference and illegal eavesdropping coexist. Thereinto, the FH(frequency-hopping) technology was adopted in the transceiver to avoid malicious interference, and the CJ technology was employed to block illegal eavesdropping. Nevertheless, the proposed architecture employs a wide frequency bandwidth, which will raise nonnegligible IQ(in-phase and quadrature) imbalances at the transceiver oscillators. In view of this, the mathematical modeling was conducted on the signal distortion caused by the imbalance of the receiving and transmitting IQ channels, a mathematical expression for SDNR(the signal to distortion-plus-noise ratio) at the receiver was provided, and a closed-form expression for the system CJSR(CJ suppression ratio) was derived. Simulation results show that the power of the signal distortion raised by transceiver IQ imbalance is much greater than that of the thermal noise. Besides, both the SDNR and CJSR will decline sharply as the transceiver IQ imbalance deteriorates, and when the magnitude and phase imbalance are 0.95 and π/50 respectively, both the SDNR and CJSR performance will deteriorate 47 dB.更多还原