固定封包長度之直接序列分碼多工/非同步阿囉哈無線網路系統於雷利衰減有限狀態馬可夫通道吞吐量分析

Throughput Analysis of DS CDMA/unslotted ALOHA Wireless Networks with Fixed Packet Length in Rayleigh Fading Finite-State Markov Channel Model

陳志豪(Chih-Hao Chen)

指導教授 ： 曾恕銘

國立臺北科技大學/電資學院/電腦與通訊研究所/碩士(2012年)

https://doi.org/10.6841/NTUT.2012.00099

摘要

在行動環境下，我們提出了應用有限狀態馬可夫通道對直接序列分碼多工/非同步阿囉哈無線網路做吞吐量的分析。有限狀態馬可夫通道模型可以描述雷利衰減程序的相關結構，而相關的程度取決於都卜勒頻率偏移。由於有限狀態馬可夫通道模型的馬可夫鏈性質，所以適合用排隊理論做吞吐量分析。我們推廣的分法，在行動環境下應該更符合真實的雷利衰減。我們考慮了兩種情況: 1) 沒有通道負載感測協定系統 2) 有通道負載感測協定系統。對於上述兩種系統，我們用排隊理論對各種平均信雜比和都卜勒頻率偏移做理論吞吐量的分析，以及計算模擬分析來匹配理論吞吐量。

關鍵字

有限狀態馬可夫通道 ； 非同步阿囉哈 ； 分碼多工 ； 吞吐量分析 ； 都卜勒頻率偏移 ； 排隊理論

並列摘要

We propose the finite-state Markov channel (FSMC) model to the throughput analysis of DS CDMA/unslotted ALOHA wireless networks in the mobile environment. The FSMC model can characterize the correlation structure of Rayleigh fading process, and the degree of correlation depends on the Doppler frequency shift. The FSMC model is suited to the throughput analysis by queueing theory due to its Markov chain nature. Our generalized scheme should be more suited to realistic Rayleigh fading in the mobile environment. We consider two cases: 1) the system without channel load sensing protocol (CLSP) and 2) systems with CLSP. For both cases, we analyze the theoretical throughput by queueing theory for various averaged SNRs and Doppler frequency shifts, and the computer simulated throughput matches the theoretical throughput.

並列關鍵字

finite-state Markov channel (FSMC) ； unslotted ALOHA ； code-division multiple access ； throughput analysis ； Doppler frequency shift ； queueing theory

參考文獻

[2] H. H. Chen and M. Guizani, “Multiple access technologies for B3G wireless communications,” IEEE Commun. Mag., vol. 43, no. 2, pp. 65–67, Feb 2005.

[3] Li-Chun Wang, Chih-Wen Chang, and H. Huang, “An interference avoidance code assignment strategy for downlink multi-rate mc-ds-cdma with tf-domain spreading,” IEEE Trans. Wireless Commun., vol. 6, no. 7, pp. 2508 – 2518, Jul. 2007.

[4] S. M. Tseng, “Sequential detection for multiuser MIMO CDMA systems with single spreading code per user,” IEEE Trans. Wireless Commun., vol. 8, no. 7, pp. 3492 – 3497, July. 2009.

[5] G. Mcgrath, “An optimization metric for air-to-ground network planning,” IEEE Trans. Wireless Commun., vol. 8, no. 5, pp. 2336 – 2340, May. 2009.

[6] A. Heidari and A. K. Khandani, “Closed-Loop Transmit Diversity with Imperfect Feedback,” IEEE Trans. Wireless Commun., vol. 9, no. 9, pp. 2737 – 2741, September 2010.