基于副载波相移键控强度调制和低密度奇偶校验码的光无线通信系统性能

Performance of Optical Wireless Communication System Basing on the Sub-Carrier PSK Intensity Modulation and LDPC Code

研究了采用副载波相移键控(PSK)强度调制的光无线通信系统在大气湍流信道下的性能,并对副载波相移键控强度调制和开关键控(OOK)两种调制方案在大气湍流信道下进行了性能比较。仿真结果显示副载波相移键控强度调制优于开关键控。在此基础上,将低密度奇偶校验(LDPC)码和置信传播迭代译码算法应用到光无线通信系统中,并结合副载波相移键控强度调制方案,在大气湍流信道中进行了仿真。仿真结果表明,低密度奇偶校验码具有优越的纠错能力并获得了较大的编码增益,上述方案满足光无线通信系统的需要。

Optical wireless communications using sub-carrier phase shift keying （PSK） intensity modulation through atmospheric turbulence channel is investigated. Sub-carrier PSK intensity modulation is compared against on/off key （OOK） modulation in the atmospheric turbulence channel. The simulation results show that sub-carrier PSK intensity modulation is superior to OOK in the presence of atmospheric turbulence. On this basis, the low density parity check （LDPC） codes and BP iterative decoding algorithm are applied into the optical wireless communication system, and it is simulated in the atmospheric turbulence channel with combination of sub-carrier PSK intensity modulation. The simulation results show that LDPC codes have excellent error correction capabilities and access to a larger coding gain,and the above scheme can satisfy the need of optical wireless communication system.