Uplink multiuser multi-access interference elimination method and device of multi-input multi-output (MIMO) system

Abstract

The invention discloses a multi-access interference elimination method of an uplink multiuser MIMO system, which relates to an advanced long term evolution system (LTE-Advanced). At the reception end of a base station, a null space matrix is obtained by utilizing the channel state information of the paired users and then constructed into a transformation matrix which does not reduce the channel multiplexing degree; and the transformation matrix is utilized to process a received signal so as to eliminate the multi-access interference between the paired users. When the users are scheduled, the different users using the same codebook are restricted from occupying a same time frequency resource and the probability that the users with relatively larger channel relativity are paired with each other is decreased, so as to minimize the influence of the transformation matrix on the effective signal strength. Simulation shows that the invention can remarkably reduce the multi-access interference of the uplink multiuser MIMO system, improve the signal to noise ratio of the user and enhance the system throughput.

Description

technical field [0001] The invention relates to the field of mobile communication, in particular to the research on multiple access interference elimination of an advanced long-term evolution system (LTE-Advanced) uplink multi-user multiple-input multiple-output (MIMO) system. Background technique [0002] The MIMO system achieves diversity gain or multiplexing gain by configuring multiple antennas at the transceiver end and using spatial channels to greatly improve the capacity and spectrum efficiency of the communication system without increasing the system bandwidth. It is the key technology of the next generation wireless communication system . The LTE / LTE-Advanced system in the 3rd Generation Partnership Project (3rd Generation Partnership, 3GPP) has conducted a lot of research on the application of the MIMO technology. At the sending end there is N t Antennas, the receiving end has N r In a MIMO system with two antennas, the capacity gain is min(N t , N r ). Howe...

AI Technical Summary

Problems solved by technology

However, the traditional MAI cancellation algorithm only considers the post-processing matrix to eliminate the MAI of paired users, and does not evaluate the influence of the post-processing matrix on the effective signal strength of the demodulation user.

However, applying a post-processing matrix to the received signal in an actual system will reduce the multiplexing of the equivalent channel, which will reduce the effective signal strength of the demodulation user and affect the improvement of system performance.

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