Multi-cell coordination large-scale MIMO pilot frequency multiplexing transmission method

Abstract

The invention provides a multi-user large-scale MIMO pilot frequency multiplexing transmission method based on multi-cell coordination. According to the transmission method, all base stations provided with a large-scale antenna array wirelessly communicate with several users on the same time-frequency resource, it is not required that the users in the same cell use complete orthogonal pilot frequency, it is not required either that different cells completely multiplex the same pilot frequency, and the users in the same cell or the different cells can multiplex the same pilot frequency. Multi-cell coordination communication is adopted, and a cell cluster is formed by the multiple cells. The transmission method includes the steps that all the cell base stations obtain statistics channel information of all the users in the cell cluster and send the information to a central control unit which takes charge of coordinating all the cells in the cell cluster; according to the statistics channel information, the central control unit allocates pilot frequency to all the users in the cell cluster and feeds back a result to all the base stations; all the base stations obtain all user channel estimations and statistical characteristics of errors of the user channel estimations by using pilot frequency signals sent by all the users, and the base stations perform uplink robust receiving and downlink robust pre-coding according to all the user channel estimations and the statistical characteristics of the errors of the user channel estimations. The transmission method can reduce the pilot frequency overhead substantially and improve net spectrum efficiency of a system and is high in adaptability to pilot frequency allocation algorithms, and uplink receiving and downlink pre-coding transmission has robustness.

Description

technical field [0001] The invention relates to the communication field of a multi-cell multi-user massive MIMO system, in particular to a multi-user massive MIMO pilot multiplexing transmission method based on multi-cell coordination. Background technique [0002] Massive MIMO technology can deeply tap and utilize spatial dimension resources, greatly improve data transmission rate, spectrum efficiency and power efficiency, and meet the needs of future broadband green wireless communication. Its unique technical advantages have attracted extensive attention from academia and industry. [0003] In a MIMO system, channel state information (CSI) is required for precoding transmission at the transmitter and signal detection at the receiver, and the acquisition of CSI is crucial to the MIMO system. The acquisition of CSI in actual wireless communication is usually based on the pilot-assisted method. However, due to the large number of base station antennas in massive MIMO, the t...

AI Technical Summary

Problems solved by technology

Although the pilot overhead is reduced, when the number of users is large or the users move fast, the length of the coherent block is short, and the symbol time that can be used to send useful data is relatively reduced. At this time, the problem of pilot overhead is still very prominent.

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