Optimization method for the number of users in large-scale multi-antenna relay system based on energy efficiency optimization

Abstract

The invention discloses an optimal energy efficiency-based user number optimization method for a large-scale and multi-antenna relay system. The system comprises a plurality of transmitting-terminal users and a plurality of receiving-terminal users, wherein the transmitting-terminal users and the receiving-terminal users form communication pairs. The information transmission between the transmitting-terminal users and the receiving-terminal users is realized via a relay node station within two time slots. All transmitting-terminal users and receiving-terminal users in the system are respectively provided with a single antenna. Each relay node station in the system is respectively provided with an antenna array of a large-scale number illustrated in the drawings of the abstract. According to the technical scheme of the invention, in order to realize that the energy efficiency of the system is maximal, the number of in-service users is adopted as an optimization variable for the establishment of a mathematical model. Since no clear analytical expression is available for a target function of the above optimization problem, the target function is approximately transformed firstly based on the law of large numbers in the large dimensional random matrix theory. After that, an approximately accurate analytical expression for the target function is figured out. Finally, a numerical solution method for realizing the optimal number of in-service users is provided based the quasi-concave characteristics of the optimization variable in the analytical expression.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a method for optimizing the number of users of a large-scale multi-antenna relay system based on optimal energy efficiency. Background technique [0002] Multiple-input multiple-output (MIMO for short) technology is playing an increasingly important role in wireless communication systems. After utilizing airspace resources, wireless communication systems have improved in terms of attainable rate, spectrum efficiency, and link reliability. Significantly improved. However, the number of antennas used in the traditional MIMO system is relatively small, including only 8-port antennas in the latest communication standard LTE-A, which is obviously far from exploring the potential rich airspace resources. not enough. Professor Thomas L. Marzetta, a scientist at Bell Laboratories in the United States, pointed out as early as 2006 that when the number of base ...

AI Technical Summary

Problems solved by technology

However, although the first method can better eliminate inter-user interference, it brings the overhead of additional time-frequency resources, resulting in a decline in the overall spectrum efficiency of the system.

The second method will greatly increase the complexity of the algorithm, and put forward higher requirements for the computing resource overhead of relay nodes and receiving end users

Although the third type can guarantee the best performance of users served at the same time, it will cause the fairness of serving users, that is, there are some users who have been unable to access the service due to channel interference.

Especially under the mainstream concept of green communication, it is very meaningful for network optimization to consider the power consumption of fixed circuits to determine the optimal number of users that the system can serve. However, this problem has not been explored by researchers.

In order to solve the problem of optimizing the number of users in a large-scale antenna relay system, we propose a model for optimizing the number of users based on energy efficiency maximization. Since the objective function in this model is too complicated and there is no precise analytical expression, the process of solving the optimization problem is very difficult. difficulty

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