Method for managing distributed dynamic spectrums in digital subscriber line uplink system

Abstract

The invention discloses a method for managing distributed dynamic spectrums in a digital subscriber line uplink system. By utilizing the characteristic that the interference of strong users on weak users is mainly at low frequency, redistribution is performed on the strong subscriber by utilizing bit movement based on bits subjected to iterative water injection predistribution. Due to the fact that each modulator-demodulator maximizes self data transmission rate and neglects crosstalk disturbance on other users when the bits are subjected to the predistribution through an iterative water injection method, the strong users seriously interfere the weak users, the data transmission rate of the weak users is low, and then serious unfairness is caused. According to the method, the bits loaded in low-frequency sub-channels of the strong users are transferred to high-frequency sub-channels as many as possible through the bit movement, so that the crosstalk disturbance is effectively inhibited, the data transmission rate of the weak users is maximized while the requirement of a target data transmission rate of the strong users is met, and the data transmission rate of the digital subscriber line system is increased.

Description

technical field [0001] The invention relates to a spectrum management technology in a wired broadband access network, in particular to a distributed dynamic spectrum management method in a digital subscriber line uplink system. Background technique [0002] The increasing demand for information in modern society, especially the rise of services such as video-on-demand and multi-person video conferencing, has made people put forward higher-level requirements for communication services and means of communication. The bandwidth of the backbone network of the current communication network, the speed of the router and the processing capacity of the server can all meet the needs of various broadband services. The biggest difficulty in establishing a broadband communication network is how to increase the transmission rate of the user access network. [0003] Due to historical reasons, the telecommunication network composed of copper twisted pair wires that provide voice services i...

AI Technical Summary

Problems solved by technology

The third layer of dynamic spectrum management (DSM 3) requires the sending end or receiving end of the digital subscriber line system to meet the cooperative relationship, but some digital subscriber line systems will have both the central office (Central Office, CO) and the remote terminal (Remote Terminate, RT ), so that the cooperation conditions cannot be met, and the third layer of dynamic spectrum management cannot be adopted; the second layer of dynamic spectrum management (DSM 2) uses the Spectrum Management Central (SMC) to collect all channel information and the needs of operators and users , to coordinate and equalize the spectrum of all modems. Although the second layer of dynamic spectrum management can effectively suppress crosstalk interference, but at the same time, the complexity of the algorithm is large, resulting in an excessive burden on the spectrum management center. Optimal spectrum equalization (Optimal Spectrum Balancing (OSB) is a typical second-level dynamic spectrum management algorithm; the first-level dynamic spectrum management (DSM 1) only requires the spectrum management center to issue a small amount of control information or even no information at all, and each modem according to its own channel The situation and the information obtained from the spectrum management center are used to allocate their own spectrum, which greatly reduces the burden on the spectrum management center. The first layer of dynamic spectrum management is also called distributed dynamic spectrum management.

[0007] Iterative Water-filling (IWF) method is very representative for spectrum management in the first layer of dynamic spectrum management, that is, distributed dynamic spectrum management. However, in the iterative water-filling method, each user maximizes its own data transmission rate and ignores Crosstalk interference to other users, especially in digital subscriber line systems with near-far effect, the iterative water injection method will cause weak users to be severely interfered by strong users, resulting in low data transmission rates or even inoperability for weak users

Based on the IWF method, Wooyul Lee proposed a Distributed Band-preference Spectrum Management (DBPSM) algorithm to improve the problem of severe interference for weak users, but the DBPSM method still leaves room for improvement

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