在異質性網路中利用多頻帶子訊框進行干擾管理

Abstract

在異質性網路中，近空副訊框是增強型干擾協調技術中很重要的一個部分，而近空副訊框主要是用來保護微型基地台的用戶不受到大型基地台的干擾。然而，大型基地台用戶的表現會受到影響因為近空副訊框會使得大型基地台的訊框空白進而降低表現。我們發現使用越多的近空副訊框會增加越多微型基地台用戶表現，但大型基地台用戶的表現也會相對下降，這是一個取捨。 如果大型基地台不要空白訊框而是降低傳送的功率，這樣就可以保護到大型基地台用戶的表現，如果這個降低的功率選擇的好，也可以使得微型基地台用戶受到的干擾不要這麼大。我們在此篇論文中提出了多頻帶子訊框這種方式來改善近空副訊框的缺點。 我們利用小基地台範圍擴展使得多頻帶子訊框的好處能夠放大，由於此篇論文的計算量很大，我們利用了粒子群聚法這種演算法來找到最佳解，根據模擬結果，多頻帶子訊框有底下幾個好處: (1)我們改善了大型基地台用戶的表現而且不會傷害到型基地台用戶的表現 (2)多頻帶子訊框比起近空副訊框來消耗了更少的能量

In heterogeneous networks(HetNets), the time domain inter-cell interference coordination techniques specified in 3GPP standard. Almost Blank Subframes (ABSs) are an important part of enhanced Inter-Cell Interference Coordination(eICIC). The purpose of ABSs is to protect users served by pico base stations(PBSs) from suffering macro base stations(MBSs) interference. However, the capacity of MBSs users have been degraded due to the concept of ABS is to blank some subframes of MBSs. We can figure out the proportion of ABSs would casue different result. The higher the proportion of ABSs, the higher the PBSs users performance and the lower the MBSs users performance. This is a trade off from the above description. If MBSs transmit with lower power subframes rather then blank subframes, MBSs users capacity can be protected and protect PBSs users when the lower power subframes is suitable. In this work, we propose Multi-tone subframes(MTSs) to enhance ABS, which is referred to half-tone since only two choices can be applied on each subframe. Cell range expansion(CRE) is introduced in 3GPP to maximum the benefit from MTSs. Because the computation of this work is heavy, we make a introduction of particle swarm optimization(PSO), which is one kind of machine learning technique to solve the problem. According to the simulation results, the proposed Multi-tone subframe has two properties: (1)We improve the performance of MBSs users without harming the performance of PBSs users. (2)The power consumption of Multi-tone subframe is less than the original ABS scenario. The green communication is achieved by our approach.