Channel estimation method and device for multi-user multi-input multi-output (MU-MIMO) system

Abstract

The invention discloses a channel estimation method for a multi-user multi-input multi-output (MU-MIMO) system. The method comprises the following steps of: A, performing least square channel estimation by using a local pilot frequency of a user I and a received signal sequence at a pilot frequency position to acquire an estimation sequence; B, performing time bias estimation and compensation before separating users; C, sending the estimation sequence subjected to the time bias compensation into a filter to acquire an initial channel estimation value of the user I, performing transformation domain cyclic shift processing on the estimation sequence subjected to the time bias compensation, and then sending into the filter again to acquire an initial channel estimation value of a user II; and D, performing time bias recovery on the two users respectively to acquire a channel estimation value at the pilot frequency position. By the method, noise is reduced when users are separated, so that the realization complexity can be reduced obviously and the performance of channel estimation can be improved; and an operational formula of the filter is simplified by using an orthogonality characteristic of the pilot frequency of the users. The invention also discloses a corresponding channel estimation device for the MU-MIMO system.

Description

technical field [0001] The present invention relates to a channel estimation method and device, in particular to a channel estimation method and device for an MU-MIMO (Multi-user Multiple-Input Multiple-Output, user multiple-input multiple-output) system in the communication field. Background technique [0002] In recent years, the wireless communication system has developed rapidly towards broadband. With this development trend, the bandwidth occupied by the wireless communication system is getting higher and higher, the transmission rate is higher and higher, and the spectral efficiency is also required to be higher and higher. Under such demands, MU-MIMO technology has been widely used in various communication systems due to its efficient spectrum utilization. Therefore, inventing a channel estimation method for MU-MIMO systems has great practical value. [0003] There are two types of channel estimation methods for MU-MIMO systems introduced in existing relevant patent ...

AI Technical Summary

Problems solved by technology

Among them, the first type of method requires at least three DFT calculations. Considering the baseband processing of multi-cell, multi-antenna and multiple groups of MU-MIMO users, this will put forward very stringent requirements on the DFT calculation unit of the hardware system, and will also bring great pressure to the system design. There are many problems; the second method requires two steps of user separation and noise reduction to obtain the frequency domain channel response value of MU-MIMO users, so the computational complexity will be at least doubled, and the user separation performance of this method It is also susceptible to the influence of time bias inconsistencies in MU-MIMO user systems

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