Method of the side-lobe suppression without the main-lobe widening for linear array beam-forming

The objective of beam-forming for sensor array is to estimate the signal arriving from a desired direction in the presence of noise and interfering signals. Although adaptive beam-forming, which is data dependent, has advantages in spacial resolution and interference suppression in many circumstances, it also has some disadvantage such as lack of robustness, time-consuming, and many of the adaptive beam-former may lose their suitability when signals from different directions are coherent. Thus, data independent beam-forming is still important for array signal processing. The simplest and the most used data independent beam-forming method is delay-and-sum method, which has the disadvantage of high side-lobe level. Array shading is widely used to suppress the side-lobe level for delay-and-sum beam-forming method, but usually will widen the main-lobe. This paper introduced a side-lobe suppression method without main-lobe widening through combining the non-weighting delay-and-sum method and array shading for linear array. Simulation showed the effectiveness of this method when there were strong interference to cause the non-weighting delay-and-sum method and array shading fail.