Space-time Coding Design Of MIMO-VLC System~2

Visible light communication(VLC)has become one of the research hotspots of wireless communication in recent years because of its advantages such as rich spectrum resources,good confidentiality,low cost and low energy consumption.In this paper,the space time block code,low power space time block code,the combination of space time block code and space modulation and the design of super orthogonal space time trellis code are studied for the space time coding scheme of MIMO-VLC system.The main work is as follows:1.The space-time block code scheme in the traditional MIMO system is extended to the MIMO-VLC scene.Combined with the characteristics of visible light communication system and aiming at MIMO-VLC system,this paper presents two methods to modify the traditional space-time block coding method and apply it to the scene of visible light communication.The first method is to transform the negative signal into the supplementary signal.The other method is to add DC bias,so that all the signals become positive signals.Both of these two methods can achieve independent decoding at the receiving end.The paper also gives the design case of the first method for two LEDs,three LEDs and four LEDs respectively,and the maximum likelihood receiving algorithm.2.A low power space-time block code design method is proposed for MIMO-VLC system.Based on the existing MIMO-VLC space time block code,the signal is transmitted in two specific LEDs in different symbol cycles,and the other LEDs do not send the signal,so the power consumption of the transmitter is reduced.Simulation results show that the proposed low-power space-time block codes not only consume less power,but also have simpler receiving scheme compared with the space-time block codes transmitted at full load.3.The STBC-SM codebook design in the traditional MIMO system is extended to the MIMO-VLC scene.A design method of STBC-SM codebook for MIMO-VLC system is proposed.By introducing super-rorthogonal codeword set and adding amplitude parameter,the discrimination of space-time coding matrix is improved.In addition,the optimal value of the amplitude parameter is calculated with the coding gain as the optimization objective.4.the design scheme of super-orthogonal space time trellis code in traditional MIMO system is extended to MIMO-VLC scene.A construction scheme of super-orthogonal codeword set for MIMO-VLC system is proposed,and the design scheme of superorthogonal space-time trellis codes is obtained by applying the super-orthogonal codeword set to common space-time trellis codes.