在第四代行動通訊中使用投機分散式空時編碼暨合作式自動重傳機制之跨層吞吐率分析

Cross-Layer Throughput Analysis for Cooperative ARQ Protocols Using Opportunistic DSTC in 4G Network

陳人維(Ren-Wei Chen)

指導教授 ： 伍紹勳

國立交通大學/電機學院/電信工程系所/碩士(2011年)

https://doi.org/10.6842/NCTU.2011.00251

摘要

在此篇論文中，主要是從跨層設計－實體層(PHY)和媒介擷取控制層
(MAC)的角度去分析使用投機分散式空時編碼暨合作式自動重傳機制時的
系統效能。為了能夠確實模擬分析媒介擷取控制層上的封包傳遞行為，針
對投機分散式空時編碼暨合作式自動重傳機制，本篇論文在媒介擷取控制
層提出了相容於4G網路(WiMAX)的通訊協定。此外，當使用投機分散式空
時編碼(ODSTC; opportunistic distributed space-time code)技術進行傳輸時，
時變衰退通道(time-varying fading channel)對於系統效能的影響在本篇論文
中也會納入考慮，因此，若傳輸時節點間的交涉協商延遲(negotiating delay)
大於通道的同調時間(coherence time)時，投機多樣性 (opportunistic diversity)
的好處便無法完全地得到。從模擬結果可以發現，投機增益(opportunistic
gain)只有當資料傳輸是在緩慢衰減通道中進行時才會存在。此外，從模擬
結果也可以發現，當資料是在緩慢衰減通道中傳輸時，使用投機式阿拉蒙
特時空編碼 (opportunistic Alamouti's Space-Time Code)來傳輸就能達到不
錯的傳輸效能。相對於緩慢衰減通道，當資料是在快速衰減通道中傳輸時，
使用投機中繼傳輸(opportunistic relaying)並不是一個有效率的方法，因此，
在此情況下，隨機選擇(random selection)中繼站(RS; relay station)來進行傳輸
是較為建議的方法。

關鍵字

合作式通訊 ； 投機分散式時空編碼 ； 跨層設計 ； 衰退通道影響 ； IEEE 802.16

並列摘要

The thesis investigates the performance of cooperative
Automatic-Repeat-reQuest protocol (ARQ) with the opportunistic distributed
space-time coding scheme from the perspective of the cross-layer (Media
Access Control, MAC, layer and Physical, PHY, layer) design. Based on the
concept of opportunistic relaying for ARQ, the corresponding MAC protocols
which are compatible to the WiMAX relay-assisted network are proposed in this
work. In addition, the time-varying fading channel is considered when using the
ODSTC scheme. Thus, the full opportunistic diversity possibly is not available
when the negotiating delay is greater than the channel coherence interval. The
simulation results show that the opportunistic gain only exists in slow fading
channel, and using distributed Alamouti code is good enough through exploiting
the opportunistic gain. On the other hand, the opportunistic relaying is not an
efficiency scheme in fast fading channel. Therefore, random selection for
choosing RS is recommended when the fading effect is serious.

並列關鍵字

cooperative communication ； opportunistic distributed space time code ； cross-layer design ； fading channel effect ； IEEE 802.16

參考文獻

[1] P. Liu, Z. Tao, S. Narayanan, T. Korakis, and S. Panwar, “CoopMAC:

A Cooperative MAC for Wireless LANs,” IEEE Journal on Selected

[2] H. Zhu and G. Cao, “rDCF: A Relay-Enabled Medium Access Control

Protocol for Wireless Ad Hoc Networks,” IEEE Trans. on Mobile

[3] IEEE standard for local and metropolitan area networks part