Unlock instant, AI-driven research and patent intelligence for your innovation.

LLR calculation method based on double Gaussian approximation

A calculation method, double Gaussian technology, applied in the field of channel decoding, can solve problems such as increasing complexity

Active Publication Date: 2021-07-06
BEIJING UNIV OF POSTS & TELECOMM
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For the case where the interference source is unknown, existing studies have added a probability density estimator to the decoder, but the iterative calculation of the probability density estimator also leads to a significant increase in complexity

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • LLR calculation method based on double Gaussian approximation
  • LLR calculation method based on double Gaussian approximation
  • LLR calculation method based on double Gaussian approximation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0075] Assuming that the sending end uses Turbo code encoding, the information bit length is 1000 bits, and the two sub-encoders generate 3-bit tail bits respectively, and the code rate is 1 / 3, then the code word length after encoding is N=3018 bits. After being modulated by BPSK, the channel gain from the sending end to the receiving end is known and normalized to 1. The receiving end receives the signal y 1 ,y 2 ,...,y N , where the number of interference sources and their channel gains are unknown; the specific process is:

[0076] Step 1: The receiver calculates the statistical average of the received signal

[0077] Step 2: The receiving end performs double Gaussian approximation on the sum of noise and interference, and calculates the parameters of the double Gaussian distribution:

[0078]

[0079] Step 3: Through the formula Calculate the LLR to get λ 1 ,λ 2 ,...,λ N ;

[0080] Step 4: Put λ 1 ,λ 2 ,...,λ N As the input of the decoder, it is decoded t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses an LLR calculation method based on double Gaussian approximation, and belongs to the field of channel decoding. In a multi-user interference scene, receiving signals are interfered by unknown interference sources with an unknown number at the same time, the sum of all interference signals and channel noise is total noise, and the method specifically comprises the steps: receiving and storing the receiving signals y1, y2,..., yN corresponding to complete code words by a receiving end; calculating the statistical characteristic of the statistical average equivalent to the received signal, and further calculating the statistical characteristic of the total noise; calculating statistical characteristics of double-Gaussian distribution according to a probability density function; calculating parameters mu and sigma under the condition of ensuring that the statistical characteristics of the total noise and the double-Gaussian distribution are the same; and finally, enabling the receiving end to perform soft demodulation on the received signal, substituting the parameters mu and sigma into the LLR, obtaining the results lambda1, lambda2,..., lambdaN corresponding to the received signal through calculation, and inputting the results into a decoder for channel decoding to obtain an expected signal. According to the method, the channel decoding performance under multi-user interference is effectively improved at the minimum cost.

Description

technical field [0001] The invention belongs to the field of channel decoding, and relates to an LLR (Log-Likelihood Ratio, Log-Likelihood Ratio) calculation problem in channel decoding under a multi-user interference scenario, in particular to a double-Gaussian approximation-based LLR calculation method. Background technique [0002] In recent years, wireless communication technology has developed rapidly, and the fifth generation mobile communication technology has also been put into use. As a key technology that can effectively improve channel reliability, channel coding plays an important role in wireless communication systems. The Turbo codes and LDPC codes widely used in 3G and 4G systems, as well as the Polar codes introduced in 5G, all have performance close to the Shannon theoretical limit, largely due to the decoding method of soft information transmission. [0003] The calculation of soft information LLR is an important link in the communication process, such as ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H04L1/00
CPCH04L1/0047H04L1/0048H04L1/0054
Inventor 付钰刘奕彤杨鸿文
Owner BEIJING UNIV OF POSTS & TELECOMM