Transmit diversity implementation through phase conjugation in line of Sight and Non Line of Sight scenerios

In this work, we have demonstrated transmit diversity using phase conjugating scheme. A six bit digital phase shifter and three voltage controlled phase shifters were developed to implement the pre-coded phase conjugate in the transmit signal. Deliberate constructive interference of the signal transmitted from multiple antennas was achieved at the desired target. The proposed scheme is demonstrated to work successfully in Line of Sight (LoS) and Non-Line of Sight (NLoS) scenarios. This technique enables control over spatial power distribution of nulls and peaks. A gain of 16 to 20 dB was achieved (If standing on the complete null) in the incident power without increasing the transmit power.