光学学报, 2020, 40 (3): 0306001, 网络出版: 2020-02-10
无线光通信中的增强型光空间调制 下载: 1100次
Enhanced Optical Spatial Modulation in Wireless Optical Communication
光通信 无线光通信 增强型光空间调制 脉冲位置调制 传输速率 误码率 optical communications wireless optical communication enhanced optical spatial modulation pluse position modulation transmission rate bit error rate
摘要
针对传统光空间调制传输速率低、激光器利用率不高等问题,提出了一种激活激光器数目可变的增强型光空间调制(EOSM)系统。通过每次激活一个或两个激光器的索引组合增大空间域映射,并结合脉冲位置调制(PPM)的特点来区分不同类的映射。详细介绍了空间域和信号域的映射规则,利用联合界技术推导出EOSM系统在弱湍流信道下的误码率的理论上界,并对EOSM系统与现有的三种光空间调制进行性能对比。结果表明:当激光器数和调制阶数固定时,EOSM系统的传输速率大于空间脉冲位置调制(SPPM)和空间脉冲幅度调制(SPAM)系统。当传输速率为6 bit/s、调制阶数为4时,EOSM系统的误码率与SPPM系统相近,但明显优于SPAM系统和广义空间脉冲位置调制(GSPPM)系统。当误码率为10 -3时,EOSM系统的信噪比比SPAM和GSPPM系统分别改善了约4.5 dB和1.2 dB。EOSM系统的计算复杂度比SPAM和GSPPM系统分别提高了17.78%和2.6%,比SPPM系统降低了70.2%。EOSM系统提高了激光器的利用率,大幅降低了系统的建设成本。
Abstract
In this paper, an enhanced optical spatial modulation (EOSM) system with a variable number of activated lasers is proposed to solve the problems of low transmission rate and laser utilization in the traditional optical spatial modulation system. The spatial domain mapping is increased by activating index combinations of one or two separate lasers each time. The characteristics of pulse position modulation (PPM) are specifically utilized to distinguish the various types of mapping. In this work, a detailed discussion of the mapping rules of the spatial domain and the signal domain is given. The theoretical upper bound of the bit error rate (BER) of the EOSM system for the weak turbulence channel is derived by using the joint bound technique. Furthermore, the performance of the proposed system is compared with that of three existing optical spatial modulation systems. The results show that the transmission rate of the EOSM system is greater than those of the spatial pulse position modulation (SPPM) and spatial pulse amplitude modulation (SPAM) systems when the number of lasers and the modulation order are fixed. Considering a transmission rate of 6 bit·s -1 and a modulation order of 4, the BER of EOSM system is similar to that of the SPPM system, but it is significantly better than those of the SPAM system and the generalized spatial pulse position modulation (GSPPM) system. When the BER is 10 -3, the signal-to-noise ratio of EOSM system is improved by 4.5 dB and 1.2 dB compared with those of the SPAM and GSPPM systems, respectively. The computational complexity of the EOSM system is 17.78% and 2.6% higher than those of the SPAM and GSPPM systems, respectively, and 70.2% lower than that of the SPPM system. Moreover, the EOSM system can effectively improve the utilization of the laser and greatly reduce the construction cost of the system.
张悦, 王惠琴, 曹明华, 黄瑞. 无线光通信中的增强型光空间调制[J]. 光学学报, 2020, 40(3): 0306001. Yue Zhang, Huiqin Wang, Minghua Cao, Rui Huang. Enhanced Optical Spatial Modulation in Wireless Optical Communication[J]. Acta Optica Sinica, 2020, 40(3): 0306001.