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    Please use this identifier to cite or link to this item: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/102943

    Title: GA、PSO 和 DDE 演化計算於多輸入多輸出無線通訊系統之研究
    Other Titles: Ga, Pso and Dde Evolutionary Computing for Multiple-Input Multiple-Output Systems in Indoor Wireless Communication
    Authors: 丘建青
    Contributors: 淡江大學電機工程學系
    Keywords: 超寬頻;多輸入多輸出;通道容量;多目標;覆蓋率;中繼天線;基因法則;粒子群演算法;動態差異型演化法;同頻干擾;空間陣列;極化陣列;Ultra-Wideband;Multiple-Input Multiple-Output;Channel Capacity;Multiple Objective Function;Received Power;Relay Antenna;Genetic Algorithm;Particle Swarm Optimization
    Date: 2013-08
    Issue Date: 2015-05-12 13:48:00 (UTC+8)
    Abstract: The channel capacities of multiple-input multiple-output ultra-wide band (UWB) systems are investigated. UWB systems possess a nature of high channel capacity, and multiple-input multiple-out (MIMO) approach can be used to enhance channel capacity effectively. Thus, it is expectable that UWB systems can be combined with MIMO approach to fulfill the necessity of high transmission rate in the future. It is well-known that UWB systems combining MIMO approach can yield high data rates in theory. As a result, we will analyze the problems on channel capacity of the combined system in the realistic environment, and propose a suitable method to tackle them. Furthermore, we will compare simulations and experimental measurements data. In the first year, an optimization procedure for the location of the transmitter in small area (<10m) MIMO-UWB wireless communication systems is presented. Based on the shooting and bouncing ray/image (SBR/Image) performance, the channel capacity and received power for any given location of the transmitter can be computed. The optimal transmitter antenna location for maximizing the channel capacity and received power are searched by genetic algorithm (GA), particle swarm optimizer (PSO) and dynamic differential evolution (DDE). Furthermore, an optimization procedure for the location of the relay transceiver in large area (>10m) MIMO-UWB wireless communication system is investigated. UWB based on the IEEE802.15.3a standard brings the convenience and mobility of wireless communications to high-speed interconnects in devices throughout the digital home and office. In general, effective selections of the relay antenna location are important for increasing channel capacity and received power in a large indoor environment. The optimal relay antenna locations for the MIMO-UWB communication systems are discussed. The multiple objective functions are the channel capacity and received power for UWB system. Then this relay antenna location problem is transformed into the optimization problem. GA, PSO and DDE optimizer are used to search minimize the relay antenna location to maximize the channel capacity and received power of the communication system. The frequency responses of different transceiver antenna locations are computed by SBR/Image techniques, and the channel frequency response is further used to calculate corresponding channel capacity. Based on the SBR/Image performance, the channel capacity and received power for any given relay antenna location of the transceiver can be computed. The optimal location of relay antennas 表 C011 共 2 頁第 2 頁 for maximizing the channel capacity and received power are searched by GA, PSO and DDE. In the second year, a UWB circular antenna array (UCAA) combining GA, PSO and DDE algorithm to maximize the channel capacity and received power. The realistic environment is investigated for line of site (LOS) and non-line of site (NLOS) scenarios. The transmitting and receiving antennas are circular array of eight UWB printed dipole antennas. A circular array of eight UWB printed dipole transmitting antenna, each element antenna feed length was regulated by GA, PSO and DDE algorithm. Channels of virtual reality, which are corresponded with wireless personal area networks (WPAN), such as digital home and digital office etc. will be built by principles of SBR/Image techniques. Performance characterizations of MIMO-UWB communication systems over channels of virtual reality are investigated. The MIMO-UWB frequency responses of the indoor channel for any transmitter-receiver location are computed by SBR/Image techniques. By using the frequency responses of multipath channel, the performance of the channel capacity MIMO-UWB system with circular antenna array can be calculated. Based on the topography of the antenna and the channel capacity formula, the array pattern synthesis problem can be reformulated into an optimization problem and solved by the GA, PSO and DDE algorithm. The GA, PSO and DDE is used to regulate the antenna feed length of each array element to maximize the channel capacity and received power performance of the communication system. The novelties of our approach is not only choosing channel capacity as the objective function instead of side-lobe level of the antenna pattern, but also consider the antenna feed length effect of each array element. The strong point of the GA, PSO and DDE algorithm is that it can find out the solution even if the performance index cannot be formulated by simple equations. Simulation was performed by UWB circular antenna array. Each array element is UWB antenna with omni-directional radiation pattern within the 3-7GHz frequency band. Finally, optimal algorithm for MIMO-UWB communication systems will be proposed tested. In the third year, a comparison of MIMO-UWB communication characteristics for different geometrical shape tunnels is investigated. UWB based on the IEEE802.15.4a standard system with single co-channel interference (CCI) is calculated in the realistic environment. Channel capacity of MIMO-UWB systems with single CCI is calculated. First, channel capacities of both MIMO-UWB systems and single-input single output ultra-wide band (SISO-UWB) systems with and without single CCI are calculated to investigate how much whether CCI effects can be reduced while the transmitter of the CCI equips only one antenna. Next, channel capacities of MIMO-UWB systems with and without the CCI are calculated while the transmitter of the CCI equips multiple antennas. Furthermore, spatial array (SA) and polar array (PA) are applied to transmitting antenna, receiving antenna. By the ray-tracing approach, two different antenna arrays are applied to our simulation. The performance of MIMO-UWB for channel capacity improvements is investigated through extensively simulations and measurements for both SA and PA. The study results quantify the effects of applying different antenna arrays on the combined system.
    超 寬 頻 (Ultra-Wideband, UWB) 系統結合多輸入多輸出(Multiple-Input Multiple-Output, MIMO)之通道容量研究。UWB 系統本身即具有高通道容量的特性,且 MIMO 可以有效的用來增加通道容量及增強傳輸距離,為了滿足未來高傳輸率的需求, 合併此二者是可以預期的。根據理論,UWB 系統結合MIMO 可以明顯的提升系統容量。 因此,本文以此合併系統為基底,分析此系統通道容量在真實的環境裡計算的問題,並 提出適合的解決方法。此外,藉由儀器測量去取得通道特性是最直接且有效的方法。本 研究經由模擬方法,並利用儀器測量的結果做比較。 第一年擬藉由 MIMO-UWB 此合併系統在真實環境下之通道容量。本研究的目標是 希望在一般小型室內環境(十公尺範圍內),透過找到最佳傳送天線位置,以演算法做『多 目標』最佳化,使系統的『通道容量提高』及『覆蓋率增大』。若在大型室內環境(超過 十公尺),則固定傳送天線位置於環境中心,透過找到最少中繼天線(relay antenna)個數 和最佳中繼天線的位置,以演算法做『多目標』最佳化,使系統的『通道容量提高』及 『覆蓋率增大』。近年來,有關UWB 系統的研究報告,大部分都是屬於短矩離測量及 模擬的室內環境,卻很少有研究報告是在室內有很多遮蔽物且較大的惡劣環境下(超過 十公尺)的情況下,如:地下室、室內停車場、辦公室、大廳或廠房,這時,有效的選擇 中繼天線和擺設位置是很重要的,在正確的選擇與擺設下,可以有效降低相同頻道的干 擾。選用中繼器價格便宜外,且利用中繼器再重新產生網路中的訊號,以便傳送到更遠 的距離。在一般室內環境中,無線訊號的傳遞容易受到環境的影響,造成無線電波到達 接收天線的路徑有多重反射、繞射、透射等路徑效應,此一現象稱為多路徑效應。而此 效應會造成符際間的干擾(inter-symbol inference, ISI),造成通訊效率降低。因此,加入 適當位置的中繼天線,及利用射線彈跳追蹤法可以模擬複雜環境、預測無線電波傳輸時 的特性以及減少工作時間與成本可以改善通訊品質、提升『通道容量』及『覆蓋率』。 本研究針對小型環境中,採用基因法則(Genetic Algorithms, GA)、粒子群聚演算法 (Particle Swarm Optimization, PSO)與動態差異型演化法(Dynamic Differential Evolution, DDE)最佳化室內的發射天線位置,探討在UWB 通訊上對通道容量的影響。在研究大 表 C011 共 2 頁第 2 頁 環境中採用演算法最佳化中繼天線位置,如此便可藉由中繼天線的設置達到延長操作距 離及提升環境『通道容量』及『覆蓋率』。 第二年探討智慧型超寬頻陣列天線,利用GA、PSO 與 DDE 演算法做最佳化天線 場型的調整,使得MIMO-UWB 系統『通道容量提高』和『接收能量增大』,達到『多 目標』最佳化。本研究中,發射和接收天線皆由8 根超寬頻偶極天線所構成之環型陣列, 使用演算法調整發射天線的激發電壓與信號聵入線的長度。針對直接波與非直接波兩種 單點接收形式的環境模擬,將接收點視為筆記型電腦。其中的要件除了通訊系統的參數 之外,還包括室內環境多路徑傳輸效應的影響,因此要解決這樣的問題可以看成一種求 解最佳化的問題。因此本研究使用 GA、PSO 和 DDE 做為最佳化的工具。和一般以 天線場型為目標函數所不同的地方是,本研究擬以室內通信『通道容量提高』及『接收 能量增大』做『多目標』最佳化,以利用演算法作最佳化的調整激發電壓大小(振幅)和 信號饋入線長度,尋找出滿足最高『通道容量』和『接收能量』時的天線場型,此種場 型最能滿足室內無線通訊的需求。 首先利用射線追蹤法計算出任意給定室內環境之頻道響應,根據已知的天線陣列以 及考慮具同步電路的脈衝無線電UWB 通訊系統,利用 GA、PSO 與 DDE 做最佳化 的運算,尋找出使得通道容量提升最高時的天線輻射場型以及系統的效能分析。並且將 此結果應用在室內無線區域的通訊上。希望藉由模擬結果,透過演算法分別地調整天線 陣列中每一個天線元件的信號饋入線長度,期望能合成出具有指向性的輻射場型。此一 研究目的指向性輻射場型能提供以下優點。(1) 在接收端能有效地接收到每根天線所幅 射出的能量,並進而提高接收端的訊雜比。(2) 此指向性輻射場型能有效地減少多路徑 效應的發生,使得信號在通道中傳輸的延遲擴散降低。 (3) 可大幅提升通道容量,提 高通訊品質。 第三年擬藉由 MIMO-UWB 此合併系統計算在隧道內之通道容量。利用802.15.4a 超寬頻通道模型下,假定隧道內駕駛傳送為單一或多個同頻干擾信號影響下,計算此 MIMO-UWB 合併系統的通道容量。另外,針對不同形狀隧道及對車輛多寡與隧道材質 對通道容量做分析。為了提升通道容量,在MIMO-UWB 系統中傳送端、接收端和多個 同頻干擾皆採用兩種天線陣列探討,分別為空間陣列(spatial array, SA)和極化陣列 (polar array, PA)。計算在多個同頻干擾下,對通道容量造成影響。最後將研究結果在同 頻干擾下,不同天線陣列應用於此合併系統的影響將量化呈現。
    Appears in Collections:[Graduate Institute & Department of Electrical Engineering] Research Paper

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