基于色移键控和有限状态机的联合编码设计

Joint Coding Design based on CSK and FSM

针对可见光通信(VLC)中拓展圆星座的色移键控(CSK)调制调制阶数一定时存在误码率性能较差的问题,文章首先对星座点进行优化设计,在保持星座点指向三角形中心不变的情况下重新设计星座结构,改变星座点位置,增大星座点间最小码距,以改善误码率性能;其次,为进一步提高VLC信号的传输质量,文章引入有限状态机(FSM)原理,进行联合调制设计,进一步改善了误码率;最后,进行了仿真验证及性能分析,仿真结果表明,相比于传统的CSK调制技术,文章提出的优化拓展圆形星座CSK和FSM联合调制有更好的误码率性能,在10-6级别误码率下,星座点数为4的CSK和FSM的联合编码(CC-FSM)相比于4-CSK有2.1 dB的增益;8CC-FSM码相比于8-CSK有1.7 dB的增益。

In the Visible Light Communication(VLC)system based on circle Color Shift Keying(CSK)modulation constellation,the bit error rate performance is poorer under certain number of modulation order.In this paper,we optimize the constellation point design,in keeping the constellation points under the condition of invariable pointing triangle center redesigned constellation structure.We change the constellation point location and increase the minimum code distance between constellation points to improve the bit error rate performance.In order to further improve the transmission quality of VLC signal,the principle of Finite State Machine(FSM)is introduced to carry out joint coding design to further improve bit error rate.Finally,simulation verification and performance analysis are carried out.The simulation results show that,compared with the traditional CSK modulation technology,the optimized extended circular constellation CSK and FSM combined coding proposed in this paper have better bit error rate performance.The gain of 4 Combination Coding-Finite State Machine(CC-FSM)code is 2.1 d B compared with that of 4-CSK,and the gain of 8CC-FSM code is 1.7 dB compared with that of 8-CSK.