Adaptive Beamforming Algorithm for DS/FH Spread Spectrum TT and C Signals

In order to solve the existing problems of antenna in DS/FH spread spectrum TT and C system such as wideband spectrum, wide range of airspace, and strong interference, a novel method was proposed to obtain a steering-invariant and frequency-invariant beampattern by combining the second-order cone programming (SOCP) constraints with linear constraints. Taking the advantages of SOCP, the beamformer design problem was converted into a FIR filter design problem with a given frequency response. For the non-linear phase characteristics of the FIR filter used for the broadband beamformer, the frequency response of the designed filter was made to approximate to the frequency response of desired filter by using the least squares error criterion. By adding the constraint condition, the algorithm was made to maintain a steering-invariant beampattern in different orientation with the broad null to reject broadband interferences. Simulation results show that the proposed algorithm can make the beampattern response approxi