IDMA及OFDMA於無線及有線通訊應用之性能評估

Abstract

近來人們提出或研發了許多新的無線和有線通訊系統，為了提供服務給複數的使用者，這些系統採用的多重存取(MA)技術對整體的效率有很大影響。顯然地，不同多重存取技術，可能適合不同環境和需求。 在眾多多重存取技術中，IDMA(交織多重存取)和I-OFDMA(交織-正交分頻多重存取, 為OFDMA的一種) 吸引我們的注意。我們分別針對兩者在無線和有線通訊的性能提出評估。 在電力線環境，因使用者共用相同或類似通道，IDMA發揮較好的頻率多樣性，位元錯誤率較OFDMA為佳。而在區域網路環境，因使用者看到的通道彼此獨立，且通道狀況比電力線好，OFDMA之位元錯誤率較佳。

Many new communication systems, wireless and wired, were proposed or developed recently. Aiming to provide services to multiple users, the multiple access (MA) scheme adopted by these systems has significant influence upon overall performance. Obviously different environments and requirements may be satisfied by different MA schemes. Among MA schemes, IDMA (Interleaved Division Multiple Access) and I-OFDMA (Interleaved-Orthogonal Frequency Division Multiple Access, a subclass of OFDMA) have drawn our attention. Our works provide performance evaluation on them respectively for both wired and wireless communications. In power line environment, channels experienced by users are identical; IDMA provides more frequency diversity and hence has better BER performance than OFDMA. In IEEE 802.11a wireless LAN environment, channels experienced by users are independent, and their conditions are better than that of power line channel; hence OFDMA has better BER performance.