Duplex wireless relay communication method based on network coding

Abstract

The invention discloses a duplex wireless relay communication method based on network coding. The duplex wireless relay communication method based on network coding is mainly used for solving the problems of lower spectral efficiency and higher system error code performance in the prior art. The method comprises the following implementation steps: (1) in a time slot 1, a user A sends a modulation signal; (2) in a time slot 2, a user B sends a modulation signal; (3) in a time slot 3, a relay station carries out network coding, demodulates two received user signals, carries out constellation rearrangement, carries out orthogonal combination and then forwards a combined signal; and (4) in the time slot 3, a base station carries out network decoding, carries out user signal separation on the received combined signal, and then carries out maximum likelihood demodulation respectively through being combined with the signals received in the previous two time slots, thereby recovering estimated information on the two users. The duplex wireless relay communication method based on network coding has the advantage that the error code performance of an orthogonal superimposition system is further improved while the spectral utilization ratio of the traditional decoding, forwarding and relaying system is increased.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, relates to cooperative relay communication technology and network coding technology, and further relates to a duplex wireless relay communication method based on network coding, which can be used in multiple access relay communication systems. Background technique [0002] With the continuous development of various wireless communication services and broadband data services, wireless resources, especially spectrum resources, are becoming increasingly scarce. In order to make full use of limited spectrum resources and improve data transmission rate, the International Telecommunication Union (ITU) regards wireless relay technology as one of the key candidate technologies for the next generation wireless communication system. But the introduction of relay transmission will lead to the decline of system spectrum utilization. In order to solve this problem, some scholars proposed to ap...

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Problems solved by technology

In the linear superposition scheme, the relay station directly superimposes the two user modulation signals linearly. The disadvantage of this method is that the two user modulation signals in the combined signal will interfere with each other during transmission, thereby reducing the system error. Code performance, and it is also not conducive to the expansion to high-order modulation

In the quadrature superposition scheme, the relay station modulates the two user modulation signals to the quadrature component and the in-phase component of the signal space, so that the two user modulation signals do not affect each other during transmission, which solves the problem of interference between user signals , but the disadvantage of this method is that the relay station usually adopts the same mapping method as the user terminal, which will cause the joint constellation of the user terminal and the relay station to present a one-dimensional feature, and does not make full use of the spatial dimension, which means that the system The bit error performance of the

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