自由空间光通信中的光广义正交空间调制技术

Optical generalized quadrature spatial modulation technology in free space optical

为了提高现有光空间调制系统的频谱效率,提出了一种在同相和正交域同时激活多根发射光学天线分别传输调制信号的实部与虚部的光广义正交空间调制(OGQSM)技术。该技术将调制符号扩展到同相和正交域,使得系统在空间域可以携带更多的比特,从而提高了系统频谱效率和误码性能。采用适用于所有湍流状态的Malaga湍流信道,分析了OGQSM系统在大气湍流、指向误差和路径损耗联合作用下的系统误码性能。蒙特卡罗仿真结果表明:与现有的光空间调制技术相比,所提出的OGQSM技术能够获得更好的频谱效率和误码性能,且接收光学天线数量与系统误码性能存在正相关关系,指向误差和大气湍流强度与系统误码性能存在负相关关系。

In order to improve the spectral efficiency of existing optical spatial modulation systems,an optical generalized quadrature spatial modulation(OGQSM)technology is proposed,in which multiple transmitting optical antennas are simultaneously activated in the in-phase and quadrature domains to transmit the real and imaginary parts of the modulated signals respectively.This technology extends the modulation symbols to the in-phase and quadrature domains,so that the system can carry more bits in the spatial domain,thus improving the spectral efficiency and bit error performance of the system.The Malaga turbulent channel which is suitable for all turbulent states is used to analyze the OGQSM system bit error performance of the proposed technology under the combined action of atmospheric turbulence,pointing error and path loss.Monte Carlo simulation results show that,compared with the existing optical spatial modulation technology,the proposed OGQSM technology can obtain better spectral efficiency and error performance,and the number of receiving optical antennas is positively correlated with the bit error performance of the system,the pointing error and the atmospheric turbulence intensity are negative correlated with the bit error performance of the system.