Implementation and performance analysis of 3-D cone and frustum filters

Two novel computationally efficient implementations for 3-D FIR cone filters are proposed in this paper. In the proposed implementations, the well-known 1-D quadrature mirror cosine modulated and 1-D directly designed temporal filter banks are cascaded with 2-D FIR circularly symmetric lowpass spatial filters to approximate the cone-shaped passband. Furthermore, the 3-D FIR frustum filters are derived from the proposed 3-D FIR cone filter implementations. The proposed implementations provide additional 2 dB signal-to-interference-and-noise ratio improvement compared to previously reported 3-D FIR cone and frustum filter implementations with reduced or equivalent computational complexity.