FPGA Implementation of LMS-based FIR Adaptive Filter for Real Time Digital Signal Processing Applications

In this paper, we study existing designs proposed for the FPGA implementation of an LMS adaptive filter. Excess use of multipliers and longer cycle periods are a few of the issues associated with the existing structures. Based on this study, we propose a design for an FPGA implementation of an LMS based adaptive filter using the Xilinx DSP48. The proposed architecture uses one set of multipliers for both filter output and weight-increment term computation. We have simulated the proposed design for a 12-tap adaptive filter in Xilinx system generator and implemented the filter using the Vivado tool set. Implementation results shows that the proposed architecture uses 3 DSP48 units compared to 36 DSP48 units for the existing architecture with the same filter of size 12, and our implementation supports a 75% higher clocking frequency than the existing design. Additionally, the proposed architecture consumes nearly 4.7 times less dynamic power than the existing architecture. Therefore, the proposed architecture is suitable for efficient FPGA realization of an LMS FIR adaptive filter for real-time digital signal processing applications.