The invention discloses a method of constructing a low density parity check (LDPC) code check matrix and an LDPC code compiling method, belonging to the field of LDPC codes and solving problems of slow material searching speed and large storage space in encoding based on the LDPC code. The method comprises steps of constructing, based on a number of variable nodes and a column cumulative error rate threshold, multiple secondary matrixes with identical dimensions and weights, wherein each secondary matrix is a cyclic shift matrix of a unit matrix; constructing a check matrix, wherein the columnaccumulative error rate of the check matrix is lower than the column accumulative error rate threshold; and if the column accumulative error rate exceeds the column accumulative error rate thresholddue to increase of channel errors, reconstructing a secondary matrix by reducing weight or increasing check nodes, wherein in check matrixes in steps (2) and (3), the position of each non-zero elementis stored through a discrete equation. In the LDPC code compiling method, the check matrix is constructed through the above method. The method simplifies computing process and saves memory space.

Method of constructing low density parity check (LDPC) code check matrix and LDPC code compiling method

The invention provides a Y-00 quantum noise stream encryption transmission method with a low bit error rate. The method comprises the steps that a transmitting end carries out the forward error correction coding of an information sequence modulated by BPSK through a generation matrix of a low-density parity check code, and obtains a coded information sequence; the sending end performs Y-00 encryption on bits in the coded information sequence bit by bit through the base sequence to obtain a plurality of encrypted coded information sequences; the sending end performs QAM modulation on the plurality of encrypted coded information sequences; the sending end performs OFDM modulation and parallel-serial conversion on each orthogonal subcarrier and transmits the orthogonal subcarriers; a receiving end receives the signals, and performs serial-parallel conversion and OFDM demodulation; the receiving end demodulates the plurality of orthogonal subcarriers QAM to obtain a plurality of encryptedcoded information sequences; the receiving end performs Y-00 decryption on the plurality of encrypted coded information sequences through the base sequence to obtain an information sequence subjectedto BPSK modulation; and the receiving end performs iterative computation through an LDPC FEC decoder to obtain an information sequence to be transmitted.

Y-00 quantum noise stream encryption transmission method with low bit error rate

The embodiment of the invention provides a method and a device for constructing an LDPC code check matrix for ultraviolet light communication. The method comprises the following steps: S1, constructing a first row of a check matrix in a size of m x n; setting i to be equal to 2, ..., m; according to the order of i from small to large, cyclically executing steps S2 - S3 to construct the ith row ofthe check matrix: S2, according to the constructed i-1th row, updating a column weight vector of the current check matrix corresponding to the i-1th row; S3, constructing the ith row of the check matrix according to the column weight vector of the current check matrix corresponding to the i-1th row. According to the method, by setting the minimum interval between the two adjacent 1 in each row ofthe LDPC code check matrix, the ISI influence of the ultraviolet light communication can be reduced, thereby reducing the bit error rate of the ultraviolet light communication; and by setting the maximum interval between two adjacent 1 in each row of the LDPC code check matrix, the check integrity of the LDPC code can be improved.

Method and device for constructing LDPC code check matrix for ultraviolet light communication

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Xin Jia

Author Tools

Chat about Author

Papers

Method and device for constructing LDPC code check matrix for ultraviolet light communication