It is well known that the performance of conventional adaptive beamformers degrades severely due to the presence of coherent or correlated interferences(multipath propagation) and various techniques have been develope...It is well known that the performance of conventional adaptive beamformers degrades severely due to the presence of coherent or correlated interferences(multipath propagation) and various techniques have been developed to improve the performance of the beamformer.However,most of the work in the past has been focused on the narrowband case.In this paper,the wideband beamforming problem in the presence of multipath signals is addressed,with a novel approach proposed by employing a pre-processing stage based on the frequency invariant beamforming(FIB) technique.In this approach,the received wideband array signals are first processed by an FIB network,and then a traditional narrowband adaptive beamformer or an appropriate instantaneous blind source separation(BSS) algorithm can be applied to the network outputs.It is shown that with the proposed structure,cancellation of the desired signal is reduced,leading to a significantly improved output signal to interference plus noise ratio(SINR).展开更多
Frequency-invariant beamformer （FIB） design is a key issue in wideband array signal processing. To use commonly wideband linear array with tapped delay line （TDL） structure and complex weights, the FIB design is p...Frequency-invariant beamformer （FIB） design is a key issue in wideband array signal processing. To use commonly wideband linear array with tapped delay line （TDL） structure and complex weights, the FIB design is provided according to the rule of minimizing the sidelobe level of the beampattern at the reference frequency while keeping the distortionless response constraint in the mainlobe direction at the reference frequency, the norm constraint of the weight vector and the amplitude constraint of the averaged spatial response variation （SRV）. This kind of beamformer design problem can be solved with the interior-point method after being converted to the form of standard second order cone programming （SOCP）. The computer simulations are presented which illustrate the effectiveness of our FIB design method for the wideband linear array with TDL structure and complex weights.展开更多
文摘It is well known that the performance of conventional adaptive beamformers degrades severely due to the presence of coherent or correlated interferences(multipath propagation) and various techniques have been developed to improve the performance of the beamformer.However,most of the work in the past has been focused on the narrowband case.In this paper,the wideband beamforming problem in the presence of multipath signals is addressed,with a novel approach proposed by employing a pre-processing stage based on the frequency invariant beamforming(FIB) technique.In this approach,the received wideband array signals are first processed by an FIB network,and then a traditional narrowband adaptive beamformer or an appropriate instantaneous blind source separation(BSS) algorithm can be applied to the network outputs.It is shown that with the proposed structure,cancellation of the desired signal is reduced,leading to a significantly improved output signal to interference plus noise ratio(SINR).
基金supported by the President Award of Chinese Academy of Sciences (O729031511)
文摘Frequency-invariant beamformer （FIB） design is a key issue in wideband array signal processing. To use commonly wideband linear array with tapped delay line （TDL） structure and complex weights, the FIB design is provided according to the rule of minimizing the sidelobe level of the beampattern at the reference frequency while keeping the distortionless response constraint in the mainlobe direction at the reference frequency, the norm constraint of the weight vector and the amplitude constraint of the averaged spatial response variation （SRV）. This kind of beamformer design problem can be solved with the interior-point method after being converted to the form of standard second order cone programming （SOCP）. The computer simulations are presented which illustrate the effectiveness of our FIB design method for the wideband linear array with TDL structure and complex weights.
