Multi-Femtocell downlink power interference control method based on game theory

Abstract

The invention discloses a multi-Femtocell downlink power interference control method based on a game theory, which mainly solves the problem that a Femtocell downlink signal generates severe interference with a downlink signal of a long term evolution (LTE) macro base station user. The method comprises the following steps of: 1) calculating throughput before an outdoor macro base station user deploys the Femtocell; 2) determining the maximum interference threshold of a plurality of Femtocell users on the macro base station user according to restricted interference conditions of the outdoor macro base station user so as to obtain an optimized model; 3) gaming between throughput loss of the macro base station user and transmitting power through the Femtocell users according to the optimized model, and calculating a Nash equilibrium point of the optimized model so as to obtain the optimal transmitting power; and 4) controlling a descending ratio of the throughput of the macro base station user to be within 5 percent according to the optimal transmitting power. A power control technology is combined with the game theory, the method has the advantages of energy saving, interference reduction, low realizing complexity and high practicality and can be used for controlling the interference caused by downlink power of a multi-Femtocell system, and the capacity of the system is improved.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a method for controlling downlink interference between multiple Femtocells and Long Term Evolution (Long Term Evolution, LTE) macro base stations, which can be used for a Femtocell transmitter in an LTE system. Background technique [0002] Femtocell is an emerging technology suitable for indoor use. It can solve the problem of large signal loss suffered by indoor macro base station users when communicating with outdoor base stations due to thick walls and windows coated with metal films. Deploying Femtocells in hotspot areas can increase the peak rate of users in these areas, so that users at the cell edge or in deep fading can still obtain better service experience. A small amount of Femtocell deployment has little impact on the existing system architecture or macro cells. Femtocells can be automatically configured and optimized, but since Femtocells...

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Problems solved by technology

Therefore, this solution cannot flexibly adjust the downlink power of the Femtocell according to the actual situation of the interference suffered by the Femtocell and the actual distribution of users of the macro base station

The second downlink power control scheme is a power control scheme based on the path loss between the Femtocell and the user of the macro base station. This power control scheme has too many parameters, and too many parameters make optimization difficult. As the environment of the Femtocell changes, the parameters Whether the update is timely and reasonable directly affects the performance of power control

The third downlink power control scheme is the GPS satellite-assisted downlink power control scheme. This scheme is also an open-loop control scheme. It mainly detects the penetration loss at the location of the Femtocell, without considering the distribution of macro users within the coverage of the Femtocell. , and does not consider the mutual interference between Femtocells. Although the interference between Femtocells and outdoor macro base station users is controllable, this solution cannot alleviate the interference between Femtocells: if the distance between two Femtocells is very close, both Femtocells will High power transmission leads to serious mutual interference between Femtocells

With the increase of Femtocell transmission power, the interference between Femtocell system and LTE macro base station and Femtocell system increases, which seriously restricts the capacity of LTE and Femtocell hybrid system, and reduces the communication quality of the system

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