Wireless communications have recently gained much popularity in various commercial applications. Because of the peculiar characteristic of radio channels, the ability for communicators to stand various kinds of interference in the open air is one of the most important issues in wireless communications. The focus of this dissertation is on the analysis and cancellation of narrowband interference (NBI) which is one very detrimental form of interference. To facilitate the analysis of SFH/DPSK under tone interfere, an analytical framework is developed for determination of the probability distribution of a corrupted differential phase. The concept of the phase characteristic function is introduced and its characterizations such as factorization are investigated. Based on it, expressions are derived for the general probability distribution of a received differential phase corrupted by signal tone interference and Gaussian noise under non-fading as well as different fading environments. Furthermore, we also derive the probability distribution of a received differential phase perturbed by multiple tone interference. Subsequently, an extensive analysis of SFH/DPSK is carried out in terms of bit error rate performance given different signalling schemes, fading environments and jamming strategies using band multitone and frequency jitter. Finally, we propose a new technique for rejection of narrowband interference based on multiple symbol detection of coherent or differential phase shift keying. We first show that the direct use of multiple symbol detection offers poor performance when narrowband interference is dominant. Our proposed technique employs a special signalling or coding scheme which is shown to be robust against narrowband interference. Our evaluation of bit error rate shows significant performance improvement in narrowband interference vis-a-vis direct multiple symbol detection. When viewed as a coding scheme, the proposed signalling scheme is significantly simpler for achieving the same coding gain than conventional error correction codes. / Graduate

藉由研究無線通信產業標準的制訂過程與主流標準的形成機制，本研究探討過去有關影響產業標準建立的文獻與個案，提出系統發展過程中，各影響因素扮演的角色與提供的功能，以瞭解在無線通信產業中，影響一標準脫穎而出成為市場主流的關鍵因素。本研究主要的研究發現如下： 一、政府的政策對標準後續發展相當重要，若政府態度是採開放競爭，則將在境內形成多種標準競爭而耗掉大部分能量，未來在標準向外推展上較吃虧。反之政府若能主導統一標準，常能使相關資源更集中焦點來發展單一標準，未來對外推展上較能成功。 二、協會能否發揮協商能力，使各業者提出之標準能相結合，是主流標準形成之關鍵之一，協會若能使各業者放棄成見，取得共識形成單一標準將有助於標準之發展。 三、對標準主導者而言，若能成為主流標準確實擁有很多潛在利益，為爭取標準的支持度，便會有很多遊說及策略聯盟產生，若能取得越多成員支持，常較能形成主流標準，因此標準擁有者若能降低權利金門檻，甚至將其免費授權並公開架構，標準成為市場主流之成長速度將會加快。但若成員過於複雜也容易阻礙標準演進的進度。 四、第三代行動電話的應用以多媒體為主，這是相當革命性的嚐試，故能否找到消費者公認的殺手級應用服務（killer application）成為成敗關鍵要素之一。 五、標準形成之發源地需有足夠的經濟規模量的支持，才能累積足夠資源向境外擴展。 六、標準形成在發酵期必須取得單一標準共識，在漸進變化期於境內快速建立成功經驗，並順利將成功複製於境外地區，這個模式較能成功成為主流標準。另在建立標準時需有明確的願景與目標、具國際化的規格設計，才可減少在對外擴展時之障礙。 / This thesis is intended to make explicit the roles played and functions provided by the various factors in the process of system development by means of an investigation of the process of the formation of a wireless communications standard and the mechanism that makes it a dominant. By studying the documents and cases on the factors affecting the establishment of a standard, we have come to recognize six fundamentals that make it stand out as a dominant. These six fundamentals are summarized as follows: 1. The policy made by the government plays an essential part in the further development of the formation of a given standard. If the government adopts an attitude of open competition, then lots of related resources will be wasted on the keen competition between vying forces in the local market, which is, in turn, detrimental to outward expansion. On the contrary, if the government integrates the related resources and helps form a unitary standard, the standard may succeed in opening other markets. 2. The Association is also an important positive contributor in the process of the formation of a unitary standard. The Association should do its best to mediate between each vying standard to reach an agreement and adopt a unitary standard, which is definitely instrumental in the further development. 3. For those who want to direct the formation of a standard and get the tremendous potential profits from it, they will do a lot of lobbying and form strategic alliances to attract more supports for the standard. When succeeding in doing so, the owners of the unitary standard can speed up the growth of its market by lowering the royalty and license limit, or even by opening its architecture with a free authorization. 4. The application of the third-generation cellular phones features multi-media, which is a considerably revolutionary attempt. Therefore, the success of it depends on whether the standard can come up with a killer application that appeals to consumers. 5. The local market from which the standard originates should be big enough to support it, so the standard can stand firm on the strong basis and reach out for other markets. 6. The formation of a standard should be based on an agreement of a unitary standard at the ferment stage. And at the transition stage, it should build up a successful experience as soon as possible in the local market and then successfully duplicate the model in the international ones. Besides, a definite goal and a clear vision as well as internationalized regulations and designs all contribute to lifting the barriers in its expanding outwards.