Quadrature amplitude modulated soft decision method and apparatus

A quadrature amplitude modulation and soft-decision technology, applied in code division multiplexing systems, electrical components, multiplexing communications, etc., can solve the problems of complex implementation and large amount of calculation, and achieve simple device implementation and simplified calculation. process, the effect of reducing computation time

Active Publication Date: 2008-03-05
LEADCORE TECH
View PDF0 Cites 14 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The present invention provides a quadrature amplitude modulation soft decision method and dev

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
  • Quadrature amplitude modulated soft decision method and apparatus
  • Quadrature amplitude modulated soft decision method and apparatus
  • Quadrature amplitude modulated soft decision method and apparatus

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] In this embodiment, calculation of soft bits by determining a piecewise function is taken as an example for illustration.

[0046] Firstly, a method for obtaining a piecewise function for calculating soft bits based on an LLR algorithm and a Max-log algorithm is described by taking a Wideband Code Division Multiple Access (WCDMA, Wideband Code Division Multiple Access) system as an example.

[0047] In the 16QAM modulation of the WCDMA system, each signal corresponds to two components of the real part (I branch) and the imaginary part (Q branch), and the amplitude of the component 1 at the sending end has four values. Where d represents the minimum Euclidean distance in the constellation diagram, for the standard 16QAM constellation diagram in the WCDMA system d = 2 10 , Please refer to Figure 1 for the constellation diagram, the order of the 4 bits of each standard constellation point sh...

Embodiment 2

[0105] This embodiment simplifies the way of calculating the soft bits in the first embodiment, and uses the minimum distance from the received signal to the hard decision boundary to determine the soft bit output amplitude to obtain the soft bits in the WCDMA system as an example for illustration.

[0106] The larger the absolute value of the soft bit, the smaller the misjudgment of the signal. Therefore, the farther the mapping point of the signal in the constellation diagram is from the hard decision boundary, the easier it is to demodulate, and the higher the reliability is.

[0107] first bit i 1 The hard decision dividing line is the straight line x=0, i 2 The hard decision boundary of is |x|=d, q 1 The hard decision boundary of y=0 and q 2 The hard decision boundary of is |y|=d, where d = 2 10

[0108] Determine the amplitude of the soft decision output according to the minimum distance from the mappi...

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

Being applicable to solve the issue that in current technique, demodulation procedure is too complex, the invention discloses simplified schemes for two algorithms. Scheme 1 is that using LLR algorithm and MAX-log algorithm simplifies current demodulation procedure into piecewise functions. Scheme 2 is that using minimum distance between the received signal and hard decision boundary determines amplitude of soft bits to simplify demodulation procedure further. First, the invention decomposes signal in orthogonal into first branch component, and second branch component, and then calculates their soft bits so as to accomplish soft decision-making procedure. In scheme 1, the equipment includes communication interface (CI), decomposition module (DM), judgment module (JM), computing module (CM), and output module (OM). In scheme 2, the equipment includes CI, DM, JM, CM, and OM.

Description

technical field [0001] The invention relates to the fields of computer and communication, in particular to a method and device for realizing soft decision of quadrature amplitude modulation. Background technique [0002] In order to improve the quality of signal transmission, digital modulation technology has been widely used, and the corresponding demodulation technology is also under development. Quadrature Amplitude Modulation (QAM, Quadrature Amplitude Modulation) is a two-dimensional modulation technology. It adopts the quadrature amplitude modulation method when it is realized. The projection of a certain constellation point on the I coordinate (the first branch) is used to modulate the amplitude of the in-phase carrier. The projection on the coordinates (the second branch) is used to modulate the amplitude of the quadrature carrier, and then the required phase modulation signal is obtained by adding the two amplitude modulation signals. [0003] In order to make full...

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): H04L27/34H04L27/38H04J13/02
Inventor 王乃博
Owner LEADCORE TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap