索引調變有別於傳統通訊方式，額外利用訊號傳送中可用的資源，根據採取的不同資源來傳送額外的訊號位元。近年來為了因應第五代行動通訊(the 5th Generation of mobile communication system, 5G)所需要面對的全新目標及不同需求，已經有許多不同維度(domain)的索引調變技術被開發出來，其中，頻域索引調變(Frequency Domain Index Modulation)是利用子載波啟動與否或者是子載波啟動位置等資源來傳送額外的位元數據，進而提升頻譜效率(Spectral Efficiency, SE)的同時也降低錯誤率(BER)。
　　此外，隨著行動通訊系統的蓬勃發展，除了發展以正交分頻多工系統(Orthogonal Frequency Division Multiplexing, OFDM)為主的全新技術，近年來也已提出了各式不同的傳輸技術，其中，通用濾波多載波系統(Universal-Filtered Multi-carrier, UFMC)是其中一種與OFDM系統架構相近的傳輸技術。UFMC系統將子載波額外切割至多個子頻帶，並在子頻帶上進行濾波，該行為可以降低頻譜的旁波瓣位準(sidelobe level)，進一步降低高旁波瓣位準所造成的載波間干擾(Inter-carrier Interference, ICI)，並且不須採用循環字首，進而達成頻譜效率的提升。然而，由於UFMC系統作為多載波傳輸技術，其自身有著高峰均值功率比(PAPR)的缺點存在，近年來大多數關於UFMC系統的研究都著重於提出降低PAPR的技術。
　　在本篇論文中，我們提出將現有及本論文提出的頻域索引調變應用於UFMC系統上，然後分析相同或相近頻譜效率下的錯誤率性能，並將頻域索引調變結合2x2與4x4多輸入多輸出UFMC系統，並評估其性能表現。

Different from conventional wireless communication, Index modulation utilizing additional resources to transmit extra bits of information. In recent years, to satisfy the new requirements of the 5th Generation of mobile communication system (5G), various dimensions of index modulation techniques have been developed. Among them, Frequency Domain with Index Modulation (FDIM) utilizes resources such as activation of subcarriers or the position of activated subcarriers to transmit extra bits, enhancing spectral efficiency (SE) and reducing bit error rate (BER).
Additionally, with the rapid development of mobile communication systems, apart from new techniques around Orthogonal Frequency Division Multiplexing (OFDM), various transmission techniques have been proposed. One of the techniques which is similar to OFDM is Universal-Filtered Multi-carrier (UFMC). UFMC divides subcarriers into multiple sub-bands and applies filtering on these sub-bands. This process reduces the Inter-carrier Interference (ICI) caused by high sidelobe level of the spectrum. Moreover, UFMC does not require the use of cyclic prefix (CP), further improving spectral efficiency. However, UFMC, being a multi-carrier transmission technology, suffers from the weakness of high Peak-to-Average Power Ratio (PAPR). As a result, recent research on UFMC has focused on proposing techniques to reduce PAPR.
In this paper, we propose the application of existing and newly developed frequency domain index modulation to UFMC systems. We analyze the bit error rate performance under similar or comparable spectral efficiency and combine frequency domain index modulation with a 2x2, 4x4 UFMC systems to evaluate its performance.

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