联合光源布局的多小区协作可见光通信系统资源分配算法

Resource allocation algorithm for multi-cell cooperative visible light communication system with joint light source layout

针对室内可见光通信(VLC)系统中存在小区间干扰的问题,提出一种联合光源布局的多小区协作多输入多输出(MIMO)正交频分多址(OFDMA)VLC系统资源分配算法。首先,在不影响照明的前提下,通过优化光源布局,将小区干扰限制在2个LED覆盖范围内;然后,引入协作MIMO技术,以用户公平性为优化目标;最后,对基于空分复用(SMP)和重复编码(RC)这2种协作模式的MIMO OFDMA VLC系统资源分配性能进行仿真。仿真结果表明:2种协作模式的MIMO OFDMA VLC系统的性能均优于单输入单输出(SISO)OFDMA VLC系统。基于RC模式的VLC系统对信道相关性鲁棒,其传输速率约为SISO OFDMA VLC系统的1.2倍。当信道矩阵条件数低于6时,基于SMP模式的VLC系统因获得较大的复用增益性能更优;当信道矩阵条件数等于2时,其VLC系统数据传输速率约为SISO OFDMA VLC系统的1.32倍。

Aiming at the problem of inter-cell interference in indoor visible light communication(VLC)systems,a resource allocation algorithm for multi-cell coordinated multiple-input multiple-output(MIMO)orthogonal frequency division multiple access(OFDMA)VLC system with joint light source layout is proposed.First,without affecting the lighting,by optimizing the light source layout,the cell interference is limited to the coverage of two LEDs.Then,cooperative MIMO technology is introduced to take user fairness as the optimization goal.Finally,the resource allocation performance of MIMO OFDMA VLC system for two cooperative modes(SMP)and repetition coding(RC)is simulated.The simulation results show that the performance of the MIMO OFDMA VLC system of the two cooperative modes is better than that of the single-input single-output(SISO)OFDMA VLC system.The VLC system based on RC mode is robust to channel correlation,and its transmission rate is about 1.2 times that of the SISO OFDMA VLC system.When the channel matrix condition number is lower than six,the VLC system based on the SMP mode has better performance because of the larger multiplexing gain.When the channel matrix condition number is equal to two,the data transmission rate of the VLC system is approximately that of the SISO OFDMA VLC system 1.32 times.