An Interference Aligned Precoding Method Based on Stiefel Manifold

Abstract

The invention discloses an interference alignment precoding method for transmitter unilateral optimization based on a Stiefel manifold, which is characterized in that the interference intensity in a minimum space signal is taken as an objective function, the objective function is reconfigured on the Stiefel manifold, an orthogonality constraint is removed, the inner product, the projection and steepest descent edge direction of the objective function on the Stiefel manifold are calculated, and interference aligned precoding is realized through a steepest descent edge algorithm based on the Stiefel manifold. As the dimensionality of the Stiefel manifold adopted in the interference alignment precoding method is smaller than that of a multidimensional complex space existing in a traditional optimization algorithm, the interference alignment precoding method has the advantages of quick convergence rate, low complexity, high system capacity and the like; and meanwhile, as only a transmitter needs to participate in the interference alignment precoding method, repeated iteration between a front communication link and a reverse communication link caused by the reason that transmitting and receiving ends must participate in an alignment as well as accompanied huge synchronism, feedback and other system overhead are avoided. The interference alignment precoding method is applicable to time-division and frequency duplex communication systems.

Description

technical field [0001] The invention belongs to the technical field of multi-antenna transmission in wireless communication, and in particular relates to a Stiefel manifold-based interference alignment precoding method. Background technique [0002] Interference alignment is a recently emerging multi-antenna transmission technology, which can greatly improve the capacity of wireless communication systems, so it has been widely valued and applied. According to "International Institute of Electronics and Electrical Engineers Information Theory Transactions" (IEEE Transactions on Information Theory, Vol.54, No.8, 2008, Page(s): 3425-3441), the core of interference alignment technology is to combine The interference signals of the data stream are aligned in one direction to reduce the dimension of the interference space, and the concept of degrees of freedom (DoF) is introduced. At present, the use of precoding to achieve interference alignment has been extensively studied as a...

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Problems solved by technology

[0003] The purpose of the present invention is to propose a transmitter unilaterally optimized interference alignment precoding method based on the Stiefel (Stiefel) manifold, to overcome the traditional method relying on the reciprocity of the channel to bring forward and reverse communication The defect of huge system overhead caused by repeated iterations of the link achieves the purpose of fast convergence, low complexity and high system capacity, and is applicable to both time division duplex and frequency duplex communication systems

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