Blackman-Harris Window functions (3-, 4-, 5-, 7-term etc.) from 16 to 64M points based only on LUTs and DSP48s FPGA resources. Main core for sine and cosine generator - CORDIC. Also for some window functions you can use Taylor series sine generator (1-order Taylor series is a good solution). Project contains Hann, Hamming, Blackman, Flat-top, Nuttal, Blackman–Nuttall, Blackman-Harris w/ N-term windows.
Please use maximum possible data width for correct calculation.
Note that 1 digital bit equals 6dB of generated signal. For example if you use Blackman-Harris 4-term (-92dB) you should use at least 16 bits plus one sign bit. Total optimal bit width = 17.
License: GNU GPL 3.0.
Integer data type and weight constants.
Code language - VHDL.
Vendor: Xilinx, 6/7-series, Ultrascale, Ultrascale+;
Target frequency: up to 400 MHz (tested on Kintex-Ultrascale XCKU040-2).
| Title | Universal window functions |
|---|---|
| Author | Alexander Kapitanov |
| Contact | |
| Project lang | VHDL |
| Vendor | Xilinx: 6/7-series, Ultrascale, US+ |
| Release Date | 20 Sep 2018 |
| Version | 1.0 |
| Component name | Function | Side lobe lvl (dB) |
|---|---|---|
| hamming_win | Hamming (Hann) | -43 |
| hamming_win | Hann | -32 |
| bh_win_3term | Blackman | -58 |
| bh_win_3term | Blackman-Harris | -71 |
| bh_win_4term | Nuttall | -93 |
| bh_win_4term | Blackman-Harris | -92 |
| bh_win_4term | Blackman-Nuttall | -98 |
| bh_win_5term | Flat-top | -69 |
| bh_win_5term | Blackman-Harris | -124 |
| bh_win_7term | Blackman-Harris 7-term | -180 |
- a0 = 0.27105140069342
- a1 = −0.43329793923448
- a2 = 0.21812299954311
- a3 = −0.06592544638803
- a4 = 0.01081174209837
- a5 = −0.00077658482522
- a6 = 0.00001388721735
it gives you up to 180 dB side lobe level.
For more information see: https://habr.com/users/capitanov/topics/