White LED is considered as a strong candidate for the future lighting technology. We have proposed an optical wireless communication system that employs white LEDs for indoor wireless networks. In this system, LED is not only used as a lighting device, but also used as a communication device. The system has large optical power and large emission characteristic at transmitter to function as lighting device. Therefore, the BER performance is degraded excessively due to the effects of inter-symbol interference. In this paper, we evaluate the performance of adaptive equalizer with LMS algorithm in visible-light wireless environment. And we show the interval of training sequence for channel estimation.