https://blog.wongcw.com/2022/01/11/%e6%96%b0%e7%a0%94%e7%a9%b6%e8%ad%89%e6%98%8e%e5%8f%af%e5%aa%b2%e7%be%8e%e7%b6%93%e5%85%b8ldpc%e7%a2%bc%e7%9a%84%e6%bc%b8%e9%80%b2%e8%89%af%e5%a5%bd%e9%87%8f%e5%ad%90%e5%b1%80%e9%83%a8%e5%8f%af/