Multiuser channel estimating and tracking method for large-scale MIMO system

Abstract

The invention provides a multiuser channel estimating and tracking method for a large-scale MIMO system. The multiuser channel estimating and tracking method comprises step 1, obtaining downlink user space channel information and space angle information through a downlink preamble frame pilot sequence; step 2, grouping downlink users according to the downlink user space channel information and the space angle information of the downlink users; and step 3, carrying out channel estimation and feedback according to the grouping condition of the downlink channel users. According to the multiuser channel estimating and tracking method for the large-scale MIMO system provided by the invention, no synchronization between the users is needed, and more user terminals can be served. Moreover, the downlink training pilot cost can be reduced, and the application of the FDD in the large-scale MIMO communication system is promoted; and the implementation complexity of the system is reduced, and the channel estimation precision in a time varying condition improved.

Description

technical field [0001] The present invention relates to the field of wireless communication, more specifically, to a method for estimating and tracking channels of multiple users in a massive MIMO system. Background technique [0002] In a wireless communication system, a modulated signal generated by a transmitter can reach a particular receiver through many different propagation paths, whose characteristics change over time due to multipath and fading phenomena. In addition, the characteristics of the propagation channel are based on the difference or change of the propagation frequency. In order to compensate the time-varying frequency selection characteristics of the propagation effect and improve the effective coding and modulation in the wireless communication system, each receiver of the wireless communication system can periodically Channel state information is collected for each frequency channel. When state information is determined for multiple channels, the rece...

AI Technical Summary

Problems solved by technology

However, in a massive MIMO communication system, the number of base station antennas is large, which is limited by time resources and frequency resources. In the process of channel estimation, the same pilot sequence needs to be reused to achieve channel estimation. Non-orthogonal pilots use It will bring channel estimation error, that is, pilot pollution problem

Furthermore, pilot pollution seriously affects the performance of massive MIMO systems; thus, how to effectively use pilot resources and reduce pilot pollution has become an important issue in massive MIMO channel estimation

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