One of the most challenging tasks in modeling a wireless channel is to handle time-varying multipath fading. There are various techniques to tackle this issue such as power control, antenna diversity etc. However, antenna diversity is more practical and effective technique to tackle dense multipath environment observed in Ultra Wide Band (UWB). In this paper, an efficient UWB channel modeling scheme is presented. First, the channel is simulated using single antenna on both sides of the system by taking into account both reflection and refraction of the transmitted ray. The dense multipath channel of UWB is then efficiently exploited by using different configuration of multiple antennas on both sides (transmit/receive sides). Simulation results show great improvement in channel impulse response (CIR) in case of multiple antennas. Moreover, this improvement in CIR is monotonically gradual in the sense that the CIR becomes denser upon increasing number of antennas on both sides of the system. The modelling scheme is based on ray tracing algorithm that has been developed using the art of computer game technology.