无线紫外光MIMO直升机助降ALOS链路性能分析

无线紫外光通信具有高速率高可靠性的特点，可以满足复杂环境下的通信。通过直升机助降的过程提出近似直视通信方式，并研究了无线紫外光MIMO系统的ALOS通信链路模型，同时计算了弱湍流条件下ALOS链路中MIMO系统的误码性能，并仿真分析其信噪比、发射功率、发射（接收仰角）以及通信距离对误码率的影响。计算分析当发射（接收）仰角小于35时，误码率随着发射（接收）仰角的增大，其增长趋势比较明显，当大于35时，误码率随着发射（接收）仰角的增大，其增长趋势变缓。结果表明，在无线紫外光ALOS链路中，采用天线阵列和多探测器的MIMO技术能够较好地降低误码率和抑制大气湍流，并提高抗衰弱能力。

Performance analysis of ALOS link by wirless UV MIMO in helicopter assisted landing

Wireless ultraviolet (UV) communication has the characteristics of high speed and high reliability, which can meet the needs of complex environment. The approximate line of sight (ALOS) communication mode was proposed through the process of helicopter assisted landing, and the ALOS link of wireless UV MIMO system was studied. Meanwhile, the error performance of MIMO system in ALOS link under weak turbulence was calculated, the influence of SNR, transmitting power, transmitting (receiving) elevation angle and communication distance on the BER were calculated and analyzed. When the elevation angle of transmitting (receiving) was less than 35, the BER increased rapidly with the increase of elevation angle, the trend growth of BER was slowing down with the increase of elevation angle when elevation was greater than 35. The result indicates that adopting the MIMO technology with antenna array and multi-detector can reduce BER, suppress the atmospheric turbulence and improve the ability of anti-fading in the wireless ultraviolet ALOS link.