Optical wireless communication systems have got more popularity in last few years due to its advantage over conventional radio frequency communication systems. This paper reports the effect of using NRZ and RZ modulation formats on the performance of optical Wireless communication (OWC) channel in terms of Q factor and BER at bit rate of 2.5 Gbps and 3 Gbps. It has been observed that RZ format gives better performance for optical wireless link in comparison to NRZ format at different bit rates.