Multi-user multicarrier short wave modulation method based on sparse codebook spreading

A modulation method and multi-carrier technology, which can be used in electrical components, transmission systems, etc., to solve problems such as insufficient anti-multi-user interference capability and serious interference.

Active Publication Date: 2019-03-19
SOUTHEAST UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Although the original pure spread spectrum technology can transmit the same signal through multiple subcarriers to resist narrowband interference, it also causes insufficient anti-multi-user interference ability
Assuming that there are J users communicating at the same time, there will be superposition of J user symbols at each frequency point after spectrum spreading, and the interference is very serious

Method used

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  • Multi-user multicarrier short wave modulation method based on sparse codebook spreading
  • Multi-user multicarrier short wave modulation method based on sparse codebook spreading
  • Multi-user multicarrier short wave modulation method based on sparse codebook spreading

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0064] Embodiment 1: λ=0 (the maximum number of users is equal to the number of subcarriers, fully loaded)

[0065] Table 1

[0066] Number of subcarriers N

64

Maximum number of users J max

64

Encoding

turbo

code rate

1 / 3

Modulation

QPSK

PN interval p

512

Sparse codebook dimension

16×32

Sparse codebook row weight w r

2

Sparse codebook column weight w c

1

The number of narrowband interference

8

frame length

2048

Signal power of each user

0dB

channel

AWGN

[0067] According to the number of subcarriers N and the maximum number of users J max User overload rate can be calculated λ=(J max -N) / N=0, so k=4, m=2 can be chosen. and choose to satisfy w r *R=w c *The smallest integer solution w of U r = 2 and w c =1.

[0068] The generated sparse codebook S with a dimension of 16×32 is as follows:

[0069]

[0070] Each row represents 4 subc...

example 2

[0083] Simulation example 2: λ=0.5 (the maximum number of users is 1.5 times the number of subcarriers, overload)

[0084] Table 2

[0085] Number of subcarriers N

32

Maximum number of users J max

48

Encoding

turbo

code rate

1 / 3

Modulation

QPSK

PN interval p

512

Sparse codebook dimension

32×48

Sparse codebook row weight w r

3

Sparse codebook column weight w c

2

The number of narrowband interference

4

frame length

2048

Signal power of each user

0dB

channel

AWGN

[0086] According to the number of subcarriers N and the maximum number of users J max User overload rate can be calculated λ=(J max -N) / N=0.5, so N=32 can be selected as the row number R of the sparse codebook, and J is selected max =48 as the column number U of the sparse codebook. and select the row weight w r = 3 and column weight w c = 2 such that w r *R=w c *U.

[0087] T...

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Abstract

The invention discloses a multi-user multicarrier short wave modulation method based on sparse codebook spreading. The invention belongs to the field of wireless mobile communication. The invention provides a multicarrier modulation scheme based on sparse codebook spreading for a scene in which multiple users simultaneously communicate in short wave sharing frequency bands, comprising the following step of: generating a sparse codebook conforming to a certain conditions to generate a sparse spreading sequence of each symbol of each user I / Q branch to complete the sparse spreading of the symbol. According to the multi-user multicarrier short wave modulation method based on sparse codebook spreading, the problem that multi-user interference and analog narrow-band interference exist simultaneously in short-wave sharing channels can be effectively solved.

Description

technical field [0001] The invention belongs to the technical field of wireless mobile communication, in particular to a multi-user multi-carrier short-wave modulation method based on sparse codebook spread spectrum. Background technique [0002] my country is the country with the largest number of fishing boats in the world. How to communicate quickly and effectively is fundamental to protect the lives and property of fishermen. According to the "General Technical Specifications for FM Radiotelephones for Fishing Vessels" issued by the Ministry of Agriculture in 2007, it is stipulated that the dedicated frequency band for FM radiotelephones for fishing vessels is 27.5-39.5MHz. It belongs to the category of short-wave communication. Shortwave mainly propagates in the form of sky wave, and the ionosphere is its natural "relay system". Short-wave communication has become one of the main means of communication in fishery communication because of its mature technology, long co...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04B1/71H04B1/7105
CPCH04B1/71H04B1/7105
Inventor 赵春明时伟姜明
Owner SOUTHEAST UNIV
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