本篇論文考量在IEEE 802.16m OFDMA Frame架構下，分析框架比例對於LRU Utilization之影響 ，並針對問題提出A Dynamic Downlink/Uplink Resource Adjustment Mechanism (DRAM)，藉此尋找出可以並行傳輸的傳輸對組合來改善LRU utilization並且同時考量Femtocells之干擾。首先DRAM利用Advanced Mobile Station(AMS)與Femto Advanced Base Station(ABS) 的位置關係建構出干擾關係圖，根據關係圖依序調整各個Femto ABS的框架比例，藉此改善LRU Utilization。最後在模擬的結果可以明顯看到DRAM之LRU utilization、system throughput以及service ratio這三項數值明顯比其他做法來的好上許多。

The thesis investigates the impact between the ratio of downlink/uplink subframes and logical resource unit (LRU) utilization in the IEEE 802.16 OFDMA systems. Based on the relationship, the thesis proposes a dynamic downlink/uplink resource adjustment mechanism (DRAM) for LRU utilization improvement by finding the concurrent transmission pairs based on the interference relationships among femtocells. First, DRAM constructs interference relationship graph based on the location information of advanced mobile stations (AMSs) and femto advanced base stations (ABSs) and adjusts the ratio of downlink/uplink subframes for each femtocell. Finally, the simulation results show that the LRU utilization, system throughput and service ratio of DRAM outperforms other related work.

Table of Contents
1	Introduction	1
2	Preliminaries	5
2.1	IEEE 802.16m Frame Structure	5
2.2	IEEE 802.16m Femtocells Architecture	6
2.3	Parallel Transmission Problem	8
2.4	Femtocell Interference Problem	9
2.5	Transmission Direction Interference	11
2.5.1	D/D and U/U Transmissions	11
2.5.2	D/U and U/D Transmissions	13
2.6	Dynamic Downlink/Uplink Region Adjustment	14
2.7	Related Works	15
3	A Dynamic Downlink/Uplink Region Adjustment Mechanism (DRAM)	19
3.1	Femto ABS Selection	20
3.2	Transmission Pairs Selection	23
3.3	Frame Ratio	26
3.4	Other Femto ABSs Consideration	27
3.5	Load Selection	27
3.6	Group of Femto ABS	28
3.7	Time complexity	28
4	Performance Evaluation	31
5	Conclusions	36
Reference	37
Appendix – English Paper	42

List of Figures
圖 (1)、IEEE 802.16m Frame Structure	2
圖 (2)、IEEE 802.16m Basic Frame Architecture  5
圖 (3)、WiMAX Femtocell system architecture示意圖	6
圖 (4)、多對傳輸對使用同一個LRU	8
圖 (5)、LRU wastage情形	9
圖 (6)、Power control示意圖	10
圖 (7)、Resource Blocking 示意圖	10
圖 (8)、相同方向Downlink傳輸造成的干擾問題	11
圖 (9)、相同方向Uplink 傳輸造成干擾問題	12
圖 (10)、相異方向Downlink/Uplink 傳輸造成干擾問題	13
圖 (11)、考量傳輸對進行相同傳輸以及相異傳輸比較圖	14
圖 (12)、Frame比例調整概念圖	14
圖 (13)、DRA(Mobihoc 2009)演算法示意圖	17
圖 (14)、DRA(VTC 2011)演算法示意圖	18
圖 (15)、網路場景以及傳輸對干擾圖	20
圖 (16)、干擾圖加入drgree概念	21
圖 (17)、各個Femto ABSs 計算total outdegree	22
圖 (18)、Average outdegree	22
圖 (19)、Intersection Part示意圖	23
圖 (20)、Femto ABS 1以及Femto ABS 3傳輸對組合	23
圖 (21)、只可進行相異傳輸方向之傳輸對組合	24
圖 (22)、Intersection Part (IP)區域內的傳輸對組合	25
圖 (23)、可進行相同傳輸以及相異傳輸方向傳輸對組合	25
圖 (24)、計算Intersection Part 示意圖	26
圖 (25)、考量Femto ABS 2之調整Frame Ratio 示意圖	27
圖 (26)、System Throughput	32
圖 (27)、Service Ratio	33
圖 (28)、LRU Utilization	34
圖 (29)、Traffic model 不同時的System Throughput	35

List of Tables
表(1)、Spare Capacity Request TLV Information	7
表(2)、Spare Capacity Report TLV Information	7
表(3)、實驗相關參數	31

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