Design and implementation of an efficient FIR digital filter

Figures & data

Figure 1. Block diagram of digital filtering process.

Figure 2. Block diagram of FIR filter.

Figure 3. Basic structure of FIR filter.

Figure 4. Design stages of digital filters.

Table 1. Filter specifications

Parameters	Values
Filter type	Band pass
Design method	FIR window (β = 0.5 for Kaiser window only)
Filter order	15
Lower cut off frequency 1	0.4
Upper cut off frequency 2	0.5

Figure 5. FIR BPF using Hanning window.

Figure 6. FIR BPF using Hamming window.

Figure 7. FIR BPF using Blackman window.

Figure 8. FIR BPF using Kaiser window.

Table 2. Comparison of 15th-order fir BPF using different window functions

Window technique	Filter order	Width of main lobe	No. of side lobes
Hanning window	15	0.20313	4
Hamming window	15	0.17969	3
Blackman window	15	0.23438	1
Kaiser window (β = 0.5)	15	0.11719	6

Figure 9. Frequency response of FIR band pass filter with no quantization.

Figure 10. BPF 1 (Quantization [16, 15] of FIR band pass filter).

Figure 11. BPF 2 (Quantization [8, 7] of FIR band pass filter).

Figure 12. BPF 3 (Quantization [6, 5] of FIR band pass filter).

Figure 13. BPF 4 (Quantization [3, 2] of FIR band pass filter).

Table 3. Performance characteristics of filters

Filter specification & hardware utilization	BPF 1	BPF 2	BPF 3
No. of nets	8,812	5,387	4,674
No. of instances	8,793	6,151	4,433
No. of gates	14,482	90,200	8,504

Figure 14. Simulink model of FIR band pass filter.

Figure 15. Structure & coefficients of 15-order BPF.

Figure 16. ASIC design flow.

Figure 17. Input and output waveform.

Figure 18. Top module of 15-order band pass filter.

Figure 19. Complete RTL schematic of BPF.

Figure 20. Complete gate level schematic of BPF.

Figure 21. Pyxis schematic of 12th Sheet.

Figure 22. Layout of 15-order band pass filter.