用於雙層毫微微細胞網路之適應性上鏈資源配置

Abstract

毫微微細胞基地台被視為是有效改善室內無線通訊容量的解決辦法。然而由於毫微微細胞網路覆蓋在現存之巨細胞網路之上，會讓使用者遭遇到複雜的跨層干擾，因此資源配置是解決干擾的必要方法。在實際系統(例如: HSDPA與LTE)中，適應性調變可根據不同之通道環境選擇適合的調變方式。在本論文中，吾人針對分碼多重接取(CDMA)及正交分頻多重接取(OFDMA)系統，提出適應性功率配置以增強毫微微細胞之吞吐量。於CDMA系統中，除適應性功率配置法之外，吾人亦提出了另一個嗅探功能與適應性功率配置法，藉以改善巨細胞之吞吐量。於OFDMA系統中，資源配置分成兩個步驟: 1. 利用測量報告或嗅探功能進行頻譜配置； 2. 根據適應性調變結果進行功率配置。電腦模擬結果顯示吾人提出方法能有效提升巨細胞內整體上鏈吞吐量。

Femtocell has been recognized as an effective solution to improving indoor wireless communication capacity. However, since the femtocell networks overlay on the macrocell networks, users suffer from the complicated cross-tier interference. Therefore, resource allocation is necessary for alleviating the interference. Adaptive modulation which is used in practical systems (e.g. HSDPA or LTE) can be adopted to select appropriate modulation according to different channel environments. In this thesis, we propose an adaptive power allocation scheme to enhance the throughput of femtocells in CDMA and OFDMA systems. In CDMA systems, in addition to the adaptive power allocation scheme, we further propose a sniffer function and adaptive power allocation scheme in order to improve the throughput of macrocells. As for OFDMA systems, the proposed resource allocation consists of two stages: 1. allocating spectrum by the measurement report or the sniffer function. 2. allocating power by adaptive modulation. Simulation results show that the proposed approaches effectively improve the total uplink throughput in macrocell networks.