Mode switching method for reducing training overhead in intelligent reflector-assisted communication system

Abstract

The invention discloses a mode switching method for reducing training overhead in an intelligent reflecting surface auxiliary communication system, the system comprises a single-antenna base station, a single-antenna user terminal and an intelligent reflecting surface consisting of N reflecting elements, and the single-antenna user terminal sends data to the single-antenna base station, a user-base station direct link is blocked by an obstacle, and data can only be sent to the single-antenna base station through the intelligent reflecting surface; a proper reflection scheme of the intelligent reflecting surface is determined by a controller, and the phase shift of the intelligent reflecting surface is dynamically adjusted so as to improve the achievable data rate of the system; and necessary information for phase shift adjustment can be obtained at the base station through uplink training and transmitted to a controller of the intelligent reflecting surface through a control link. According to the method, statistical and instantaneous channel state information is comprehensively utilized, an intelligent reflecting surface reflection scheme is properly selected, the training overhead can be effectively reduced, and the system performance is improved.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a mode switching method for reducing training overhead in an intelligent reflective surface assisted communication system. Background technique [0002] With the commercialization of the fifth-generation (The 5-th Generation, 5G) mobile communication system, the research on the sixth-generation (The 6-th Generation, 6G) mobile communication technology has started, pursuing faster and more reliable data transmission Connect with everything. Reconfigurable Intelligent Surfaces (RIS) can significantly improve the spectral efficiency and energy efficiency of wireless networks by reconfiguring the wireless propagation environment. Specifically, the smart reflector is composed of a series of passive components, and each component can independently cause some changes of the incident signal such as phase, amplitude, frequency and so on. When the quality of direct communication i...

AI Technical Summary

Problems solved by technology

However, due to the passive reflection of smart reflector elements, in terms of training duration, the channel training overhead usually grows linearly with the number of smart reflector elements

Although a larger N increases the signal strength, it also leads to a longer training duration, which reduces the effective data transmission time in the limited coherence time

In order to reduce the training overhead of smart reflector-assisted communication, one solution is to activate only part of the smart reflector elements for transmission, however, this is at the cost of the smart reflector elements not being fully utilized

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