Effect Analysis of Time and Carrier Frequency Offset on the Performance of Distributed Transmit Beamforming for Emergency Radio

Anotace: In emergency radio scenario, distributed transmit beamforming (DTBF) enables a set of distributed radio nodes to transmit cooperatively to get a better performance. DTBF performance has been analyzed for various node distributions in the literature. However, time offset (TO) and carrier frequency offset (CFO) may exist between transmitting nodes, due to each radio node is equipped with its own clock circuit and local oscillator. Effect analysis of TO and CFO on DTBF performance is an open issue. This paper evaluates the effect of TO and CFO on performance of DTBF for arbitrary node distributions. In this study, TO and CFO are converted into phase offset (PO), and non-parametric kernel method is used to calculate the PDFs of node and offsets. Theoretical analysis and simulation results show that TO and CFO result in degradation of the mainlobe power and affect the beampattern characteristics.