By using on-off-keying (OOK) non-return-to-zero (NRZ) modulation and encodi ng technique,a pair of portable visible light communication (VLC) transmitter and receiver are designed and realized based on ARM7processor (PLC2148).The transmitter contain s encoder module,light source driver and white light-emitting diode (WLED),while the rece iver includes VLC detector,signal processing circuit and decoder module.The spectral characteris tics of WLED and VLC detector,as well as the time- and frequency-domain electro-optical-elec tro (EOE) responses of VLC channel are experimentally studied.The VLC structure and principle are described,the communication software and protocol are compiled,and both hardware and software are integrated.With the developed devices,the point-to-point VLC data-link is est ablished,and data transmission experiment is performed.The results reveal that for the transmitt er,in order to drop the bit error ratio (BER) to an acceptable level,a modul ation coefficient within the range of 0.68－1.00is preferred,and a suitable bias voltage range is desired under a def inite amplitude of alternative modulation signal,whereas for the receiver,under a certain thresho ld voltage,the VLC transmission presents band-pass characteristics.Under the optimized system parameters,the communication distance is about 0.5m,the maximum bit rate is u p to 4Mbit/s,and the BER is less than 10－6.By using WLED array as light source,a longer communication distance can be achievable,and therefore this system possesses potential applications fo r indoor and outdoor data links.