Interference alignment method applied to partly communicated MIMO interference broadcast channels

Abstract

The invention provides an interference alignment method applied to partly communicated MIMO interference broadcast channels. The method includes the steps that (1) base stations which interfere each user are obtained so that communication information of a whole system can be obtained; (2) a receiving filter equation and a pre-coding matrix equation are constructed for each cell according to the communication information of the whole system, the smallest number of effective inter-cell interference channels between each cell and interference source base stations of the corresponding cell is obtained according to soluble constraint conditions of all the receiving filter equations and the pre-coding matrix equations, and accordingly the smallest number of antennas needed by each base station of each cell is obtained; (3) interference alignment is achieved according to the smallest number of the antennas needed by each base station of each cell and the corresponding smallest number of effective inter-cell interference channels obtained in the step (2). Channel capacity and user freedom are improved to the largest extent with low algorithm complexity, and meanwhile, the number of the antennas used by the base stations is reduced.

Description

technical field [0001] The present invention relates to the technical field of wireless communication physical layer, in particular, the present invention relates to an interference alignment method applied to partially connected MIMO interference broadcast channels. Background technique [0002] Multiple-input and multiple-output (Multi-input Multi-output; MIMO) is an abstract mathematical model used to describe a multi-antenna wireless communication system. Demodulate the original information. As we all know, in the downlink communication of a multi-cell cellular network, the base station in each cell serves multiple users on the same resource block at the same time. In the whole system, there is not only inter-cell interference, but also inter-cell user interference, and the interference will affect the signal Receiving quality reduces the capacity of the entire system. In this paper, this channel is referred to as a MIMO interference broadcast channel. [0003] Existin...

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Problems solved by technology

[0029] However, in practical systems, the MIMO interference broadcast channel system is often not a fully connected MIMO interference broadcast channel system, but a partially connected MIMO interference broadcast channel system, that is, due to the influence of path loss and spatial correlation, some receivers and other There is no interference between the sending ends of the cell, so it is only partially connected

In this case, if the existing interference alignment closure algorithm is directly applied, it will lead to a waste of base station antenna resources

[0030] The iterative algorithm can adapt to the partially connected MIMO interference broadcast channel system, but it needs to solve the precoding matrix of the transmitting end and the receiving filter of the receiving end in turn, and iterate alternately until convergence. The algorithm complexity is very high and the realizability is poor.

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