多个参考点光源间的信号相互干扰，使得室内可见光通信定位系统的精度不高。为此提出一种基于码分多址（CDMA）调制的可见光定位算法，利用扩频码的正交性，对每个发光二极管（LED）所发出的身份识别（ID）信息进行扩频处理，在克服了码间干扰的同时，提升了信道的容量。接收端由自适应滤波器分辨出解扩后的ID信息以及对应的信号强度，根据ID信息确定定位的位置区域，根据衰减强度确定定位点与各LED的距离，利用接收信号强度（RSS）三角定位算法实现接收机的定位，并采用分集接收技术来提高接收增益以提升定位的精度。仿真结果表明，该定位系统最大误差为6.18 cm，超过88%的定位点的测量精度被控制在5 cm以内。该系统不仅实现了较高精度的定位，而且易于控制、稳定性好，具有广阔的应用前景。

Due to the inter symbol interference between multiple reference point sources in the positioning system, the positioning accuracy of the indoor visible light communication positioning system is decreased. Therefore, a positioning algorithm of visible light communication based on code division multiple access (CDMA) modulation is proposed. The identity (ID) information of every light emitting diode (LED) source is broadcasted by using the orthogonality of the spread spectrum code. The inter symbol interference is overcome and the capacity of the channel is enhanced by using the spread spectrum. At the receiver end, ID information and the signal strength of each LED are distinguished by adaptive filters. The location area of each LED and the distance between receiver end and each LED can be determined according to the ID information and the signal attenuation intensity, respectively. The positioning of the receiver can be realized by using the received signal strength (RSS) triangulation positioning algorithm. Furthermore, the receiving gain is improved by means of diversity reception technique, and finally the positioning accuracy is improved. The simulation result shows that the maximum error of the proposed positioning system is 6.18 cm, and more than 88% of the positioning point can be of the positioning accuracy less than 5 cm. The system not only achieves a good positioning accuracy, but also has a good stability and is easy to control, which will have broad application prospects.