Channel estimation method for underwater sound orthogonal frequency division multiplexing

A channel estimation and orthogonal frequency division technology, which is applied in the field of channel estimation to reduce Gaussian noise and interpolation error, can solve the problem of increasing transmit power, etc., and achieve the effect of improving accuracy, improving decision performance, and reducing interpolation error

Inactive Publication Date: 2012-10-10
HARBIN ENG UNIV
View PDF2 Cites 25 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Use the superposition sequence to estimate the channel in real time, and use the judgm

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
  • Channel estimation method for underwater sound orthogonal frequency division multiplexing
  • Channel estimation method for underwater sound orthogonal frequency division multiplexing
  • Channel estimation method for underwater sound orthogonal frequency division multiplexing

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0032] 1. Using LS algorithm to estimate the channel information at the pilot based on the comb pilot structure

[0033] Due to the complexity and change of the underwater acoustic environment, the communication channel is in a fast fading environment, and the channel characteristics within an OFDM symbol will also change significantly, and the comb pilots are evenly distributed in each OFDM symbol. Continuously distributed, with strong anti-fading ability, suitable for fast fading channels, so choose the channel estimation method based on comb structure. The inserted pilot frequency shall meet the following requirements in the time domain and frequency domain:

[0034] N f ≤ 1 τ max ΔF c - - - ( 1 )

[0035] N t ≤ 1 2 f d T - - - ( 2 )

[0036] Where N f Is the number of subcarriers of the pilot frequency interval; τ max Is the maximum delay of the channel; error! The reference source was not fo...

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 belongs to the field of underwater sound communication, and particularly relates to a channel estimation method for reducing gaussian noise and interpolation error in channel estimation. The channel estimation method for underwater sound orthogonal frequency division multiplexing comprises the following steps that (1) channel frequency response estimation is obtained through the channel estimation method based on a least square method; (2) noise reduction is carried out on the pilot frequency response estimation through a wavelet noise reduction method to obtain the channel frequency response subjected to noise reduction; (3) the channel frequency response of a data sub-carrier is obtained by carrying out a discrete Fourier transform interpolation method on the channel frequency response subjected to noise reduction; and (4) the received data is balanced through the channel frequency response of the data sub-carrier, the balanced data is encoded and re-modulated, comb-shaped pilot frequency is converted into block-type pilot frequency, and the received data is judged, fed back and balanced through a block-shape minimum mean square error channel balancing method. According to the channel estimation method for underwater sound orthogonal frequency division multiplexing, the impact of the channel noise on channel estimation and the interpolation error are reduced, and the judging performance and the channel estimation precision are improved.

Description

Technical field [0001] The invention belongs to the field of underwater acoustic communication, and particularly relates to a channel estimation method for reducing Gaussian noise and reducing interpolation error in channel estimation. Background technique [0002] Orthogonal Frequency Division Multiplying (OFDM) technology is a high-rate wireless transmission technology that can effectively suppress inter-symbol interference and is widely used in underwater acoustic communications. Due to the particularity of the underwater acoustic communication environment, the transmission of information requires time-varying and frequency-selective fading channels. To achieve demodulation and recovery at the receiving end, the relevant information of the channel must be known. Therefore, channel estimation is very important for OFDM systems. [0003] In OFDM underwater acoustic communication, the inherent noise of the underwater acoustic channel has a relatively large impact on channel estimat...

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): H04L25/02H04L27/26H04B13/02
Inventor 郑彩云马雪飞乔钢张可周锋孙宗鑫刘凇佐章佳荣马璐廖佳玲
Owner HARBIN ENG UNIV
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