Performance Analysis of Digital Retrodirective Array Antenna System in Presence of Frequency Offset

In this paper, we design and analyze a digital retrodirective array antenna (RDA) system based on bandpass sampling for wireless communication. The proposed system has low power consumption thanks to increased signal to interference noise ratio (SINR) because digital RDA can automatically make beam toward source with no information about the direction of incoming signal. Also, this paper presents a robust communications system to frequency offset due to digital PLL. Digital PLL can automatically compensate for frequency offset which occurs because of different frequency between transceivers. Simulation results show that the proposed scheme has better BER performance about 5 dB than that of without phase conjugation when the array elements are three.