Hybrid transmission method of joint Doppler compensation in large-scale MIMO (Multiple Input Multiple Output) high-speed moving scene

Abstract

The invention discloses a hybrid transmission method of joint Doppler compensation in a large-scale MIMO (Multiple Input Multiple Output) high-speed moving scene, and specifically aims to solve the problems of Doppler shift, high computational complexity, low throughput and the like in large-scale MIMO high-speed railway communication. The method comprises the following steps: acquiring initial channel state information; acquiring an actual angle of arrival and a beam gain of an incident signal according to beam alignment; estimating the Doppler frequency shift, designing an angle-domain beamshaping matrix, and compensating for uplink and downlink frequency offset; performing channel tracking; designing a beam-domain beam-forming matrix to eliminate the interference between upstream and downstream users; and performing data transmission. The hybrid transmission method of joint Doppler compensation has the characteristics of compensating for the Doppler shift, reducing pilot overhead,improving system throughput and the like for the large-scale MIMO high-speed moving scene. The method can be well applied in a wireless communication scene.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, relates to transmission technology in wireless communication, is a hybrid transmission method of joint Doppler compensation in a large-scale MIMO high-speed mobile scene, and particularly relates to the problem of uplink and downlink transmission in large-scale MIMO high-speed rail communication . Background technique [0002] In massive MIMO high-speed rail communication, the train speed is up to 300 km / h. The coherence time of the channel is shortened, and at the same time, it presents fast time-varying characteristics. Traditional channel estimation methods have high pilot overhead and are difficult to effectively estimate channel state information. At the same time, the high-dimensional nature of massive MIMO channels makes training and transmission computationally complex. Under the condition of limited coherence time, the lower data transmission rate is difficult to meet th...

AI Technical Summary

Problems solved by technology

[0009] Existing transmission schemes fail to solve common problems such as Doppler frequency shift, pilot overhead and computational complexity when optimizing system throughput

When the train is moving at high speed, the Doppler frequency shift will bring a large frequency deviation to the signal, and the demodulation of the signal and the transmission precoding will bring additional errors; due to the shortened coherence time, frequent channel training compresses the data transmission time, a huge Pilot overhead deteriorates system performance and reduces system throughput; although the massive MIMO antenna array has good spatial resolution, its diversity gain and multiplexing gain can be used to improve system throughput, but its high-dimensional characteristics bring beamforming huge computational complexity

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