Self-directed beamforming IF receiver for broadband communication using low frequency loop control

Abstract

Self-directed beamforming system is to calculate phase difference from signals received at each element of the array antennas with digital signal processing and estimate the direction of arrival of the signal, and form a main beam to the direction. When conventional self-directed beamforming method is applied to broadband communication, the processing of broadband signals as many as antenna elements is required, thus it is difficult to add the method to mobile terminals. We have proposed self-directed beamforming method easily applied to broadband communication. In this method beams were controlled with phase information extracted from low frequency component of received signal. In this paper, prior to verification at RF-band, IF receiver modules were fabricated and the correct operation of the proposed method was confirmed. BF experiment using 2Gbps QPSK signal assuming IEEE 802.15.3c was performed. As a result of synthesis of four IF modules, improvement of the SNR approximately proportional to the number of the synthesized modules was confirmed.