在本篇論文中，我們介紹了L. B. Milstein提出的Parallel combinational System，這是一種藉由增加展頻碼傳送數目的變化性來提高頻寬利用效率的系統，不過由於檢測方式的限制，使得這個系統無法達到最佳的頻寬利用效率。所以我們提出了另一種檢測方式，希望藉由新的檢測方式來估測接收訊號，可以得到更好的頻寬利用效率。
當我們採用最大似然函數法則的信號檢測方式之後，便可以解決Parallel combinational System中，由於使用展頻碼個數的不同，所帶來的判決臨界值變動的問題。如此一來，我們便不用限制發射信號同時使用展頻碼的個數，因此展頻碼傳送數目的變化性就增加了，更進一步地，便可以達到更好的頻寬利用效率。
最後，針對這樣的一個新的系統架構，我們還做了一些不同通道環境下的位元錯誤率分析，希望藉由這些分析看出新的系統在不同的通道環境所受到的影響。

In this thesis a new type of “Parallel Combinational CDMA System” will be introduced. The proposed scheme is one kind of multi-code CDMA systems, which can greatly increase the bandwidth efficiency of a communication system. We also propose a detection method, which in particular suits well the signal detection in a CDMA system based on the parallel combinational architecture.

The proposed high bandwidth-efficient CDMA system can be used for any type of wireless communication systems with only a limited increase in hardware complexity, that is the need of a bank of correlator receiver in parallel to perform the signal detection. Both multiple access interference and multipath interference will be considered in the analysis given in this thesis. The study on the subject will also be accompanied by computer simulation, which will be used as a benchmark to the results obtained from the analysis.

It is concluded from this thesis that the proposed new type of “Parallel Combinational CDMA System” has a great potential for the applications in the future wireless communications.

中文摘要i
英文摘要ii
致謝iii
目錄iv
變數列表vi
圖目錄viii
表目錄xxiv
第一章 導論1
1.1 研究動機1
1.2 論文架構2
第二章 多重序列分碼多工系統之比較3
第三章 Parallel Combinatorial System之發射信號架構下兩種信號估測方法之比
較9
3.1 單用戶下採用個別檢測法的錯誤率9
3.2 單用戶下採用聯合檢測法的錯誤率18
3.3 兩種估測方法之比較23
3.4 多用戶下採用個別檢測法的錯誤率27
3.5 多用戶下採用聯合檢測法的錯誤率36
3.6 信號星座的選擇法45
3.7 效能比較48
3.8 討論59
第四章 高頻寬利用效率分碼多工系統效能分析63
4.1 在AWGN通道中之效能分析63
4.1.1 單用戶下的錯誤率分析66
4.1.2 多用戶下的錯誤率分析66
4.2 衰減通道中之效能分析75
4.2.1 衰減通道之成因75
4.2.2 Rayleigh衰減通道中之效能分析77
4.2.3 Nakagami-m衰減通道中之效能分析79
4.3 效能比較83
4.4 討論92
第五章 高頻寬利用效率分碼多工系統在多重路徑下的理論分析93
5.1 採用傳統接收機的高頻寬效率分碼多工系統的效能分析93
5.2 採用RAKE接收機的高頻寬效率分碼多工系統的效能分析108
5.3 Nakagami-m衰減通道中採用RAKE接收機的高頻寬效率分碼多工系統的效能分析116
5.3.1 MRC RAKE接收機下的效能分析116
5.3.2 EGC RAKE接收機下的效能分析117
5.4 效能比較119
5.5 討論133
第六章 結論134
參考文獻136
附錄A137

[1] N. Guo and L. B. Milstein, “On rate-variable multidimensional DS/SSMA with dynamic sequence sharing,” IEEE J. Select. Areas Commun., vol. 17, May 1999.
[2] P. K. Enge and D. V. Sarwate, “Spread-spectrum multiple-access performance
of orthogonal codes: Linear receivers,” IEEE Trans. Commun.,
vol. COM-35, pp. 1309–1319, Dec. 1987.
[3] C.-L. I and R. D. Gitlin, “Multi-code CDMA wireless personal communications
networks,” in Proc. IEEE Int. Conf. Commun. (ICC’95), Seattle, WA, vol. 2, pp. 1060–1064.
[4] S. Sasaki, H. Kikuchi, H. Watanabe, and J. Zhu, “Performance evaluation
of parallel combinatory SSMA systems in Rayleigh fading channel,” in Proc. IEEE 3rd Int. Symp. Spread Spectrum Techniques and Applications (ISSSTA’94), Oulu, Finland, vol. 1, pp. 198–202.
[5] S. Haykin, Communication Systems, 4rd ed. New York: John Wiley & Sons, 2001.
[6] S. Verdú, Multiuser Detection. Cambridge, U.K.: Cambridge Univ. Press, page 101, 1998.
[7] John. G. Proakis, Digital Communications, 4rd ed. New York: McGraw-Hill, 2001.
[8] Mohamed-Slim Alouini,Sang Wu Kim, and Andrea Goldsmith, “Rake Reception With Maximal-Ratio And Equal-Gain Combining For DS-CDMA Systems In Nakagami Fading”Universal Personal Communications Record, 1997. Conference Record., 1997 IEEE 6th International Conference on , Volume: 2 , 12-16 Oct. 1997 ,age(s): 708 -712 vol.2
[9] John. G. Proakis, Digital Communications, second ed. New York: McGraw-Hill, 1989.