ldpc codes

Set h as the parity-check matrix with a row weight of d. Q is the transpose matrix with a row weight of M. For LDPC codes, there are d/nH′=h QT is a parity matrix for public key cryptography. It is not a parity-check matrix of the old password G (with H. gt=0), just a parity-check matrix for the new password g′,Have h′ G′t=h PT (S-1 G PT) T= h PT P GT (S-1) T= H. GT (S-1) T= 0 · (S-1) T= 0.Because h′ GT =h

the document was published in MATLAB and the simulation did not run out. CCSDS standard LDPC Code simulation This script completes the simulation of the process of LDPC coding for Deep Space communication task in the CCSDS Standard (O1) version, and gives the result of bit error rate simulation when the information bit length is 1024 and the bitrate is 1/2. Written by: Cao Wenhui Last modified: 20

Relationship between original codes, reverse codes, and supplementary codes in the computer, and source code Complement Recently, I have been covering questions about C and pointers, and I have learned how to fill in a question. I have searched my mind and found that the concept is vague. Just now that the application for the podcast has passed, let's try the wat

The Bootstrap Metronic framework is used to generate and print bar codes and QR codes. bootstrapmetronic In many projects, generating and printing bar codes and QR codes is also a common operation. In Web projects, we can use JS to generate many bar codes and QR

[Core tips] Identifying distorted verification codes is not the only way to identify humans. How should designers change the verification codes? How should we design the mobile device verification code that may be coming soon? 　What is a verification code? In the eyes of ordinary users, the verification code is definitely an annoying thing, especially for myopia users. We have no idea why we always need to

Interchange Between Binary Gray Codes and natural binary codesYouzhiyu, Institute of optoelectronic technology, Chinese Emy of SciencesDownload Sample projectIn the precise positioning control system, it is very important to accurately measure and control the object location to improve the control accuracy. At present, there are two ways to detect the position: one is to use a location sensor, the displacement measured from the transmitter through A/D

[Code implementation] PHP generates various Random verification codes, and php generates verification codes. Address: http://www.phpthinking.com/archives/531 Verification codes are very important in WEB applications. They are usually used to prevent users from submitting forms maliciously, such as malicious registration and login, and malicious Forum bumping. Thi

Php generates image verification codes-five verification codes are attached, I used to output the verification code in the past. I used JavaScript to generate a verification code string at the front end, and then passed it to the backend to output the verification code image using PHP. In this way, you do not need to use $ _ SESSION to pass the verification code value during verification. You can directly u

What's the use of a hash codes in Java? Java uses hash codes for the same reason described above-to efficiently retrieve data from hash based collections. If the objects of your class is not used as keys in a hash based collection, for example, in a Hashtable, HashMap, etc, You need isn't even worry about hash codes for your objects at all.You can compute hash co

Details of various HTTP return status codes and return Status Codes If a request sent to your server requires that a webpage on your website be displayed (for example, when a user accesses your webpage through a browser or crawls a webpage through Googlebot ), the server returns the HTTP status code to respond to the request. This status code provides information about the request status, telling Googlebot

Sample codes for using SkiaSharp to implement verification codes for ASP. NET Core and skiasharp Preface This article does not implement a complete verification code sample, but provides another idea for using the Drawing API in. NET Core 2.0 and demonstrates it in the form of a simple Demo. Skia Skia is an open-source two-dimensional graphics library that provides a variety of common APIs and can be run on

HTTP status codes and Status Codes An error may occur when the browser requests services from the web server. This may return the following series of status messages:1xx: Information Message: Description: 100 Continue The server only receives some requests, but once the server does not reject the request, the client should continue to send other requests. 101 Switching Proto

Update all mnemonic codes and mnemonic codes Two functions are required: USE [oa erp]GO/***** Object: UserDefinedFunction [dbo]. [f_ch2py] Script Date: 12/31/2014 17:12:26 ******/SET ANSI_NULLS ONGOSET QUOTED_IDENTIFIER ONGOALTER function [dbo]. [f_ch2py] (@ chn nchar (1 ))Returns char (1)AsBeginDeclare @ n intDeclare @ c char (1)Set @ n = 63 Select @ n = @ n + 1,@ C = case chn when @ chn then char (@ n) el

Generate simple verification codes based on PHP, and generate simple verification codes based on PHP. If you don't talk much about it, paste the Code directly. The specific code is as follows: For ($ I = 0; $ I The above code is a simple verification code generated based on PHP introduced by the small Editor. The code is accompanied by a comment. If you have any questions during the reference process, plea

The Form Verification codes and Form Verification Codes Verification code is a commonly used function for registration, login, and other forms. to prevent malicious forms from being entered and submitted continuously, this poses a security risk. Generally, the verification code image can be switched randomly. The form can be successfully submitted only after the verification is successful remotely. Impleme

Bitmap = Encodingutils.createqrcode (text, $, $, log O.ischecked ()? Bitmapfactory.decoderesource (Getresources (), R.mipmap.ic_launcher): NULL); Imageview.setimagebitmap (bitmap); } } }); } @Override protected void Onactivityresult (int requestcode, int resultcode, Intent data) {Super.onactivityr Esult (Requestcode, ResultCode, data); if (ResultCode = = RESULT_OK) {Bundle

There is a small number of C ++ source codes that need to be translated into other source codes. for moderators and experts, please visit. Delphi/Windows SDK/API Http://www.delphi2007.net/DelphiAPI/html/delphi_20061121222102188.html The source code below is used to determine the encoding of the data stream, provided by a friend named jiangsheng. Thank you first. However, I will not use C ++. I am eager to u

. Fetch task Properties Tscheduletask.getscheduleproperty (unique identifier, tqbparcel)02. Machine Code and registration code tsoftwarrant* * Machine code is divided into four sections, different sections with-separated, each segment value length can be 4,5,6 three kinds of optionsA. Fetch machine code: Need to configure the required format string in advance each section length and custom initialization encryption key value Varykey;Tsoftwarrant.getmachinecode;B. Take registration code: Need to

Call codesoft to print codes, batch continuous printing, variable printing, and codesoft codes. Call the codeSoft template to implement batch continuous printing. Code: Create tag 1. lab. Add two variables var0 and var1. Using LabelManager2; String strFile = System. windows. forms. application. startupPath. toString () + "\ 1.lab"; lbl = new LabelManager2.ApplicationClass (); lbl. documents. open (strFil

Detailed description of random graphic verification codes generated by python, and detailed description of python verification Codes Use the pillow module to generate a random image verification code using python. 1. Install the pillow Module pip install pillow 2. Basic use of the pillow Module 1. Create an image From PIL import Image # defines the use of the Image class to instantiate an Image of a length