Multi-source Heterogeneous Signal Interference Suppression Method Based on Signal Subspace Alignment

Abstract

The invention relates to an interference suppression method based on signal subspace alignment for multi-source heterogeneous signals. The interference suppression method based on the signal subspace alignment for the multi-source heterogeneous signals comprises the steps that the precoding vectors of private signals and public signals in the heterogeneous signals sent by each communication node are determined respectively; each communication nodes sends three paths of private signals and three paths of public signals according to the corresponding determined precoding vectors in the multiple access stage; a relay node receives and decodes the mixed heterogeneous signals sent by all the communication nodes, and a coding estimated value generated after subspace alignment is obtained; the relay node sends broadcast signals after conducting physical-layer network coding on the coding estimated value and conducting weighting on a precoding transmission vector; the communication nodes conduct interference suppression on the received broadcast signals by means of the received precoding vectors, network codes of equivalent received signals of the communication nodes with interference signals eliminated are decoded, and then an estimated value of a signal expected to be received is obtained. By the adoption of the interference suppression method based on the signal subspace alignment for the multi-source heterogeneous signals, interference between the private signals and the public signals of multiple communication users can be eliminated, and the interference suppression complexity can also be lowered.

Description

technical field [0001] The invention relates to the field of multi-user relay cooperative transmission, in particular to a multi-source heterogeneous signal interference suppression method based on signal subspace alignment. Background technique [0002] The Two-way Relay Network (TWR) technology represented by Physical-layer Network Coding (PNC) is currently one of the most promising technologies for improving the spectrum efficiency of relay networks. . At present, research schemes combining PNC and multiple-input multiple-output (Multiple-Input Multiple-Output, hereinafter referred to as MIMO) technology are emerging. An important research direction in these schemes is to use pre-coding technology at the source node to "transform" MIMO-based Wireless two-way relay channel (hereinafter referred to as TWRC), so that two-way signals can have the same channel gain and phase in the relay. After "signal alignment", the relay only needs to detect the "superimposed signal" of t...

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Problems solved by technology

[0005] The co-channel multi-user interference suppression method disclosed in Chinese invention patent CN201110066539.3 can be performed well under the condition that the number of communication users is small, but this method still has some shortcomings: when the number of communication users increases, in order to reduce the number of communication users and the constraints on the number of relay station antennas, and to eliminate the interference of signals between multiple users, to ensure that the zero-space suppression method can be successfully implemented during interference suppression, the antenna selection algorithm must be used, which undoubtedly increases the computational complexity and interference suppression complexity.

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