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

An anti-time-varying channel interference method for ofdm systems using tridiagonal weighting matrices

A weighted matrix and time-varying channel technology, applied in the field of OFDM systems, can solve problems such as high computational complexity and system BER performance deterioration, and achieve the effect of improved computational complexity

Active Publication Date: 2022-07-19
ZHEJIANG GONGSHANG UNIVERSITY
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the use of a full-dimensional matrix, there is a problem of high complexity in the calculation of its weighting; in addition, due to the nonlinear relationship between BER and SINR, the improvement of subcarrier SINR may cause the deterioration of system BER performance

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
  • An anti-time-varying channel interference method for ofdm systems using tridiagonal weighting matrices
  • An anti-time-varying channel interference method for ofdm systems using tridiagonal weighting matrices
  • An anti-time-varying channel interference method for ofdm systems using tridiagonal weighting matrices

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0053] The present invention will be further described below with reference to the accompanying drawings.

[0054] refer to Figure 1 to Figure 5 , without loss of generality, the simulation parameters of the OFDM system used are shown in Table 1. The input signal of the system adopts QPSK modulation, and the channel is a time-varying multipath channel under the Jakes model, considering the Doppler effect caused by fast movement. The generated time-domain channel coefficient matrix is ​​mainly determined by the channel power delay profile (Power Delay Profile, PDP) and the Doppler frequency shift (fd); and the value of the Doppler frequency shift is determined by the moving speed (v), in the OFDM system. The relationship between the two is expressed as fd=(v·N·fc) / (fs·3.6·3e8).

[0055]

[0056] Table 1

[0057] In the simulation comparison of the accompanying drawings, the design method of the full-dimensional weighting matrix comes from reference 1: A.Stamoulis A, S.N.D...

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

A method for resisting time-varying channel interference in an OFDM system using a tridiagonal weighting matrix. First, a P-BEM technique is used to estimate the reconstructed channel coefficient matrix H tv , and used for the formula calculation of the subsequent SINR; then, the mathematical representation of the SINR is modeled for the tridiagonal weighting matrix W to obtain the SINR of each sub-carrier m ; Express the diagonal coefficient as a vector w, and further convert the formula to obtain the SINR expressed by w m . Then, according to the theoretical conversion formula of SINR and BER, BER is obtained m , and set the subcarrier average BER as the cost function of the w optimization problem. The gradient algorithm is used to minimize the cost function, and the optimal tridiagonal weighting matrix coefficient vector w is obtained, and the tridiagonal weighting matrix W is reconstructed; finally, the weighting matrix W is used at the receiving end of the OFDM system. The invention can alleviate the interference between sub-carriers, improve the bit error rate performance of the system, and effectively reduce the complexity of implementing matrix weighting.

Description

technical field [0001] The present invention relates to the technical field of mobile communication, is suitable for OFDM systems, and is a method for resisting time-varying channels to cause Inter-Carrier Interfence (ICI) in a fast moving environment. The time-varying channel causes the Doppler frequency shift of the received signal, which destroys the orthogonality between subcarriers, thus resulting in ICI. By optimizing the design of the additional tridiagonal weighting matrix at the receiving end of the OFDM system, the method can alleviate the inter-subcarrier interference, improve the Bit Error Rate (BER) performance of the system, and effectively reduce the computational complexity of matrix weighting. Background technique [0002] OFDM has the characteristics of simple system implementation and strong resistance to inter-symbol interference, and has been widely used in various wireless communication systems in the 4G era, such as LTE-A and Wi-Fi; at the same time, a...

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 Patents(China)
IPC IPC(8): H04L27/26
CPCH04L27/2688H04L27/2691H04L27/2695
Inventor 闻建刚华惊宇李枫王安定
Owner ZHEJIANG GONGSHANG UNIVERSITY