In wireless communications has one characteristic that is the phenomenon of multipath fading, it takes a technology that could make the reflection signal does not eliminate the primary signal. The use of multiple antennas at the transmitter and the receiver is expected to result in improved quality of the wireless communication service. This technique is known as MIMO (Multiple Input Multiple Output). One scheme is MIMO STBC (Space Time Block Code), which has a subclass of OSTBC (Orthogonal Space Time Block Code). The principle OSTBC is sending some signal replicas information on the independent channel fading in orthogonal signal format, so that at least one signal receiver who did not experience the worst fading. So with the process of sending data faster and more reliable and mark with BER (Bit Error Rate) is low. The test results obtained on average use of the antenna, the more the better values obtained difference SNR BER 10-3 ± 2 to ± 5dB of each receiving antenna. Keywords : Multipath fading, OSTBC (Orthogonal Space Time Block Code), rat
