Multicell self-adaption cooperative transmission method on basis of delayed feedback

Abstract

The invention discloses a multicell self-adaption cooperative transmission method on the basis of delayed feedback. The cooperative transmission method is carried out according to the following steps: firstly, an average movement speed of users in a plurality of cells which take part in cooperation is researched, a corresponding doppler frequency offset is calculated and a channel delay correlation coefficient is obtained; then one user is selected from each cell by round-robin scheduling to wait for data transmission and a codebook known by a base station end is generated for the user; the user estimates channel information and a path power attenuation factor by receiving a pilot signal sent by a base station and feeds back the information to the base station; and finally, the base station determines an adopted cooperative transmission mode according to the information fed back by the user and information of the calculated channel delay correlation coefficient and the like, completes precoding in a corresponding mode and carries out data transmission. The multicell self-adaption cooperative transmission method can be effectively applied to actual scenes and the reachable transmission speed and the frequency spectrum utilization rate of a system can be improved.

Description

technical field [0001] The invention relates to an adaptive cooperative transmission method in a multi-cell environment, and belongs to the field of cooperative transmission in a multiple-input multiple-output (MIMO) system in a multi-cell environment. Background technique [0002] At present, in the case of increasingly tight wireless resources, in a multi-cell environment, the use of multi-antenna and global frequency reuse technology can fully tap and utilize space resources, and maximize spectrum utilization and power efficiency. However, co-frequency coverage will inevitably lead to significant Inter-Cell Interference (ICI), and the resulting performance degradation of cell-edge users has become an increasingly prominent problem, seriously restricting the further improvement of the system's achievable transmission rate. In order to cope with this challenge, in recent years, some scholars have continuously proposed that the cooperation of multiple base stations in adjace...

AI Technical Summary

Problems solved by technology

This scheme will lead to a certain quantization error between the system channel information obtained by the base station and the real channel information, and the size of this quantization error is determined by the capacity of the feedback link

In addition, when the feedback mechanism is used, there is also the problem of information delay caused by the feedback link, that is, the feedback information obtained by the base station is not the channel information at the current moment, but the channel information before a certain delay

Under the influence of the above factors, the downlink information obtained by the base station does not completely match the real channel information, resulting in a significant decline in the performance of the adaptive transmission scheme based on ideal channel information. Under the condition of channel information, the problem of adaptive switching between JP and CBF cooperative modes

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