Deisgn of Look-up Table Based Architecture for Wideband Beamforming

Abstract—Wideband beamforming with a real-time array testbed will be studied in this paper. The algorithm and im-plementation architecture on wideband beamforming will be the main focus. The contribution of this paper can be summarized in the following three aspects. First, the channel imbalances among different RF chains will be taken into account. The equivalent complex baseband impulse responses of RF chains are measured from the AFRL TELA testbed. The second contribution is that the novel architecture of wideband beamforming is proposed. Look-up table (LUT) based architecture is exploited to replace the pre-steering delay component to avoid fractional delay—one implementation bottleneck. In addition, the general optimization issue for wideband beamforming is formulated as semi-definite programing (SDP), which can be efficiently solved by the convex optimization tool, e.g. CVX. Index Terms—wideband beamforming, look-up table, SDP, steering vector, filter bank, fractional delay. I