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

Soft-decision LLR calculating method of Turdo and LDPC transcode used for two-level modulation input

A calculation method and soft decision technology, applied in the field of communication, can solve problems such as unrealistic

Active Publication Date: 2009-11-18
CHONGQING JINMEI COMM
View PDF0 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, during real-time data transmission, such as voice calls on traditional telephones or cellular telephones, video conference calls, etc., requesting retransmission is unrealistic

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
  • Soft-decision LLR calculating method of Turdo and LDPC transcode used for two-level modulation input
  • Soft-decision LLR calculating method of Turdo and LDPC transcode used for two-level modulation input
  • Soft-decision LLR calculating method of Turdo and LDPC transcode used for two-level modulation input

Examples

Experimental program
Comparison scheme
Effect test

example

[0051] The initial value of the LLR corresponding to the AGC automatic gain control output data is as follows Figure 5 shown. If the AGC automatic gain control output data agc_d(n) is greater than The soft decision data is saturated to take if less than The soft decision data is saturated to take It can be seen from the figure that agc_d(n) is greater than The initial value of the output LLR is kept at 4.1846agc_d(n) less than The initial value of the output LLR is kept at -4.1846. Because the LLR calculation process avoids the case where the denominator is equal to 0 in division, slice(n) is equal to and The probability range of is compressed from the interval [0, 1] to the interval [0.015, 0.0985], so the corresponding maximum and minimum initial values ​​of LLR are respectively

[0052] L(r(n)) max = ln(0.985 / 0.015) = 4.1846

[0053] L(r(n)) min = ln(0.015 / 0.985) = -4.1846

[0054] In practical applications, you can refer to Figure 5 According to the ...

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 a soft-decision LLR calculating method of Turdo and LDPC transcode used for two-level modulation input, which comprises the steps of: 1) carrying out automatic gain control (AGC) to demodulation sample data so as to adjust the signal amplitude thereof and leading the signal energy to be kept as Es; 2) carrying out soft-decision to AGC output signals so as to obtain soft-decision data slice(n) and calculating the probability that slice(n) is equal to Es and -Es respectively, by linear function; and 3) carrying out log-likelihood ratio (LLR) calculation according to the probability and obtaining the measured estimation value of LLR. The method has the beneficial effects that: after the method is adopted, the mapping relationship of the soft-decision data and the estimation value of LLR can realize table lookup by existing software, and the processes with extremely high complexity, extremely large operand in the prior art can be replaced with table lookup.

Description

technical field [0001] The invention relates to a decoding technology in the communication field, in particular to a soft-decision LLR calculation method for Turbo and LDPC decoding of two-level modulation input. Background technique [0002] Data transmitted through the channel is disturbed, and errors may be introduced in the transmitted data. Inserting check information into the sent data can detect receiving errors and determine whether errors are introduced after the sent data is transmitted through the channel. A common practice is to transmit data in packets, and add cyclic redundancy check (CRC) information to each packet, and perform a CRC check on the received data to determine whether there is an error in the received data during reception. [0003] When transmitting data in non-real time, the data can also be transmitted multiple times through retransmission to overcome data errors caused by channel interference. However, when real-time data is transmitted, suc...

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
Patent Type & Authority Applications(China)
IPC IPC(8): H03M13/25H03M13/27H03M13/11
Inventor 陶小鱼杨波李建国刘佳
Owner CHONGQING JINMEI COMM