Method for resisting interference in multiple-group multiple-user two-way relay network

Abstract

The invention relates to a method for resisting interference in a multiple-group multiple-user two-way relay network. The method is implemented through the following two stages: 1) a multiple-access stage, at which all users simultaneously transmit information to a relay node; and 2) a broadcast stage, at which the relay node conducts certain processing to signals received at the multiple-access state and then broadcasts to all users, and the users conduct decoding to complete two-way information exchange. The processing operation which is conducted by the relay node to the naturally superposed signals which are received at the multiple-access state is the core of the invention, and comprises the following steps that: a) the relay node decodes the received signals to restore information of users; b) physical-layer network coding is conducted to the information of the users who belong to the same group; and c) superposition coding is conducted to network coded symbols obtained in the step b and then the network coded symbols are broadcasted to all users in the form of time-space codes. By adopting the physical-layer network coding and the superposition coding, the situation that system performance is deteriorated due to interference between groups and interference in the group can be resisted. Specifically, the physical-layer network coding can eliminate the interference in the group and the superposition coding can resist the interference between groups. According to theoretical analysis and simulation experiments, by using the method, better system performance can be obtained.

Description

technical field [0001] The invention relates to a method for combining physical layer network coding and superposition coding against two types of interference in a multi-group multi-user bidirectional relay network - intra-group interference and inter-group interference, belonging to the technical field of wireless communication. Background technique [0002] Bidirectional relay networks have attracted the attention of both academia and industry due to their potential advantages in extending network coverage and improving system spectral efficiency. The concept of relay technology first originated in the Ad hoc network. Since the power of radio waves attenuates with the increase of the transmission distance, when the attenuation reaches a certain level, the receiving end cannot detect the expected information from the weak received signal. That is to say, if the distance between two nodes exceeds the effective coverage range of the antenna, then the two nodes cannot comple...

AI Technical Summary

Problems solved by technology

For Class II and III two-way relay networks, beamforming is an effective method to combat interference, but the beamforming method has very strict requirements on the antenna configuration of the system: the number of relay antennas must be greater than or at least equal to that of all users The sum of the number of antennas, otherwise the relay will not have enough degrees of freedom to resist interference

When the antenna configuration of the system does not meet the requirements of beamforming, it is a very challenging problem to deal with the deterioration of system performance caused by the two types of interference

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