The effects of microwave oven over the IEEE 802.11 FHSS wireless LAN card

[[abstract]]We have investigated the effects of microwave ovens over the IEEE 802.11 FHSS wireless LAN card. The measured MAC frame error rate (FER) is affected by the microwave ovens. The signal spectrum radiated from the microwave oven can be used to verify the measured FER data. The performance of the specific bands assigned to some geographic locations in the IEEE 802.11 standard have been discussed in the paper. From these measurement results we can obtain that the performance of some channels within the IEEE 802.11 FHSS wireless LAN card can be seriously deteriorated. Therefore, the location of the microwave oven and the specific channels for the wireless LAN card should be pre-determined according to the experience guideline.[[conferencetype]]國際[[conferencedate]]19991018~19991022[[booktype]]紙本[[conferencelocation]]Beijing, Chin

The impact of laser phase noise on the coherent subcarrier multiplexing system

[[abstract]]In coherent optical subcarrier multiplexing (CSCM) systems, the laser phase noise may cause signal spectrum broadening and hence, causes significant deterioration in the system performance. The impact of phase noise on the CSCM system is analyzed in terms of carrier-to-noise ratio, intermodulation distortion, and adjacent channel crosstalk. The optimal modulation index and carrier to noise ratio are also presented. Some numerical results are outlined[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子

Multi-rate transmissions in infrastructure wireless LAN based on IEEE 802.11b protocol

[[abstract]]We discuss the issues of providing multiple data rates (1/2/5.5/11 Mbps) over an IEEE 802-11 infrastructure wireless network. With the characteristic of modulation schemes, the data rate of the wireless network is inversely proportional with the transmission distance. A moving mobile station needs to dynamically adjust the modulation scheme to keep the connection alive and to achieve the maximum network throughput. To do this, the mobile stations are requested to detect the distance between access point and itself from time to time. A simple broadcasting approach is proposed for mobile stations to detect their locations in the wireless network. Based on this information, the mobile node can easily determine the proper transmission rate[[conferencetype]]國際[[conferencedate]]20011007~20011011[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]Atlantic City, NJ, US

Design of optical decoder and optical address translator for high speed optical switching network

[[abstract]]In this paper, the author studies the key technologies for the high speed optical switching network using the optical header/payload discriminator, optical decoder and optical address translator for header recognition, decoding and translating addresses directly in the optical domain. This system utilizes the optical ring resonator (ORR) for header/payload discriminator (OHPD). The optical delay line decoder (ODLD) and translator (OTR) for decoding and translating optical address for routing control are designed. For ODLD, the hierarchical prime code structure is designed with delay line logic to increase the channel capacity. For OTR, the optimal code mapping algorithm and serial or parallel code architectures are designed[[conferencetype]]國際[[conferencedate]]19970811~19970814[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]Natal, Brazi

Maximal simultaneous users code set selection in FO-CDMA using genetic algorithm

[[abstract]]In this paper we propose a solution to find the maximal simultaneous users code set by genetic algorithm. By this methodology, the code set can be exactly selected which is error free. Besides, the computing time for this methodology is much faster than the heuristic solution as the prime number P is larger than 5.[[notice]]補正完畢[[conferencetype]]國際[[conferencedate]]19991101~19991101[[iscallforpapers]]Y[[conferencelocation]]Beijing, Chin

Implement an all in one 315MHz ASK UHF receiver

[[abstract]]An all in one integrated 315MHz ASK UHF receiver is proposed in this paper. This receiver has several characteristics, first RF-in data-out all in one function, second without any spiral inductor and final filter all on chip (Crols et al., 1995; Wilson et al. 1991). We design a monolithic ultra-high frequency (UHF) receiver including RF front-end, intermediate-frequency (IF) stage and base-band stage. The RF front-end end include single end low-noise amplifier (LNA) without on-chip spiral inductors and a mixer which down-converters the LNA output to 2.25MHz IF. The IF stage includes 1MHz band pass filter, variable-gain amplifier (VGA), automatic gain control (AGC) loop and peak detector. The base-band stage includes on-off keying (OOK) demodulator and slicing comparator to output digital signal. The UHF receiver was implemented in a UMC 0.5μm CMOS process. The receiver sensitivity is -73dBm and 2.4kbits data rate. The chip consumes 13mA and size in 1370×1370μm2. In the future, we will increase the sensitivity to -100dbm, then this receiver will be manufactured into product. Thus, the design of a high sensitivity and low cost UHF receiver will be the most important area for the future work.[[conferencetype]]國際[[conferencedate]]20040818~20040821[[iscallforpapers]]Y[[conferencelocation]]Chengdu, Chin

Pilot-Assist Channel Estimation for Multi-input Multi-output (MIMO) 2x2 OFDM System

[[conferencetype]]國際[[conferencedate]]20090917~20090918[[booktype]]紙本[[conferencelocation]]Aizu-Wakamatsu, Japa

A self-routing frequency division multiple acdess network

[[conferencetype]]國際[[conferencedate]]19940706~19940713[[booktype]]紙本[[conferencelocation]]Santa Barbara, C

[[alternative]]Combined Prime Codes for Optical Spread Spectrum Communication

[[abstract]]在光纖展頻通訊中, 若使用質數值為P之修正質數碼做為展頻碼,它的長度為P/sup 2/chips, 但其解碼容量卻只有P/sup 2/個。若需要較大之解碼容量時, 必須使用較大之P值而使得展頻碼可能太長而不切實際。本論文改用由多個質數P/sub 1/、P/sub 2/...P/sub k/之修正質數碼所合併的新碼做為展頻碼, 結果只需(P/sup 2//sub 1/+P/sup 2//sub 2/+Λ+P/sup 2//sub k/) chips之長度即能擁有(P/sup 2//sub 1/×P/sup 2//sub 2/×Λ×P/sup 2//sub k/)之解碼容量, 而且其解碼系統只需沿用原修正質數碼之簡易結構即可。[[abstract]]The Modified Prime Code with prime number P, used in optical spread spectrum systems has the property that both its code length and the number of codes are P/sup 2/. Thus, in a system that needs large capacity of codes, the code length may be too large for practice. In this paper, a new code which combines several modified prime codes, with prime number P/sub 1/P/sub 2/...P/sub k/ respectively, is proposed. It is shown that the new code can be use in the same basically encoding/decoding structure as the modified prime code. Also, it is shown that using only(P/sup 2//sub 1/+P/sup 2//sub 2/+Λ+P /sup 2//sub k/) chip length, the new code can reach the capacity of (P/sup 2//sub 1/×P/sup 2//sub 2/×Λ×P/sup 2//sub k/) codes.[[sponsorship]]淡江大學 電機工程系[[conferencetype]]國內[[conferencetkucampus]]淡水校園[[conferencedate]]19981218~19981219[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]臺北縣, 臺

[[alternative]]Site Survey Tool for Wireless Network Based on Auto- Calibration

[[abstract]]建築物的牆或是物件對於無線區域網路都有不同的影響。我們可以使用一個GUI的程式去分析這些路徑損耗。首先, 讀取一個建築物的 AutoCAD檔並給予各物件參數, 然後去計算Tx和Rx之間的路徑損耗。最後我們以Tx為中心去分析出一個Rx可接收訊號的最佳範圍。設計這個無線區域網路規劃之自動校準規劃工具的主要目的就是以預測估計的方法找出放置Rx的最佳位置。[[abstract]]The wall or object of the building has different effects on the path loss contour for wireless transmission. We can use a GUI program to analyze the path loss contour. Loading an AutoCAD files and giving the loss parameter, then we can calculate the path loss between Tx and Rx. For the wireless LAN, we calculate the path loss contour of the mobile users in the Ad Hoc network. In order to determine the good reception locations for the mobile user, we design this Site Survey Tool to find the optimal locations for the mobile users.[[sponsorship]]淡江大學 電機工程系[[conferencetype]]國內[[conferencetkucampus]]淡水校園[[conferencedate]]19981218~19981219[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]臺北縣, 臺