THE HYBRID FROSTS BEAMFORMING ALGORITHM FOR MULTIPLE JAMMERS SUPPRESSION

An adaptive array system can automatically adjust its directional response to null the interferences or jammers and thus enhances the reception of the desired signal. For some condition, the conventional Frost's beamforming algorithm may have some problems associated with performance degradation in multiple jammers environment. It causes the convergence time to be essentially dependent of the jammers' power ratio. In this paper, a new hybrid adaptive beamforming algorithm is derived in the discrete cosine transformed domain for multiple jammers suppression. Overall performance improvement, in terms of convergence rate and the computational requirement is investigated. From computer simulation results, we found that the presented method outperformed the conventional Frost's linear constraints LMS algorithm, in terms of the capability of jammers suppression and the rate of convergence. Moreover, the performance of the HLCLMS adaptive beamforming algorithm using the DHT and DFT are also investigated. From simulation results, we observed that the performance of the HLCLMS with DHT is very similar to the one using DCT. However, when DFT is applied to the HLCLMS adaptive beamforming algorithm the performance will be degraded compared to the HLCLMS algorithms using the DCT and DHT.