Dissertations / Theses on the topic 'Bi-directional communications'

京都大学
新制・課程博士
博士(情報学)
甲第23328号
情博第764号
新制||情||130(附属図書館)
京都大学大学院情報学研究科通信情報システム専攻
(主査)教授 原田 博司, 教授 守倉 正博, 教授 大木 英司
学位規則第4条第1項該当
Doctor of Informatics
Kyoto University
DFAM

Dense wavelength division multiplexing (DWDM) is becoming the technology of choice for meeting the increasing bandwidth demands in optical networks. DWDM has been used to increase the capacity of long-haul optical transport systems. Efforts are being made to move DWDM into the broadband access network serving residential and business subscribers. First, a new centralized DWDM PON scheme is demonstrated for bi-directional upstream and downstream transmissions. The proposed DWDM PON scheme is implemented using optical carrier suppression and separation (OCSS) technology to generate a wavelength pair from a single laser source at the central office. This method enables the co-location of both upstream and downstream DWDM transmitters in the central office. In addition, the complexity, cost, and maintenance of the optical network unit are reduced by enabling wavelength independent operation. Second, a new multistage architecture is proposed for the delivery of information to groups of subscribers located at different distances from the central office. A 25 GHz DWDM comb is generated using OCSS technology, and error-free transmission of four 10 Gbps channels is demonstrated. Finally, a new wide area access network with bi-directional DWDM amplification using semiconductor optical amplifiers (SOAs) is demonstrated. The detrimental effect of SOA crosstalk resulting from cross gain modulation can be suppressed using a constant intensity modulation format such as differential phase shift keying (DPSK). The feasibiity of bi-directional DPSK transmission of 16 interleaved DWDM channels using an in-line SOA has been studied experimentally. In addition, the reduction of bi-directional SOA reflections has been realized by optimizing the SOA bias current and facet reflectivities.

From a theoretical perspective, the bi-directional broadcast communication which follows from the network coding idea has been studied extensively in the literature. However, despite the potential gain, not much practical work has been realized. In this thesis, we designed and implemented the traditional bi-directional relaying with 4-phases and the bi-directional communication with XOR network coding with 3-phases schemes using Wireless Open Access Research Platform (WARP) boards. Our experimental results show that when we have low packet error rate, there is an approximately 30% throughput gain in the bi-directional communication with network coding. However, when the link quality degrades, the bene t of the bi-directional communication with network coding scheme becomes less apparent and the traditional bi-directional relaying tends to perform better. It is observed that the performance relates directly to the packet-error rate of the weakest node-relay link.

Soma-germline interactions play conserved essential roles in regulating cell proliferation, differentiation, patterning, and homeostasis in the gonad. In the Drosophila testis, the JAK-STAT, Hedgehog, BMP and EGF pathways are used to mediate soma-germline communication via paracrine signalling. In this thesis, I aim to shed light on the role of juxtacrine signalling, mediated by gap junction proteins, during early spermatogenesis in the fly testis. My analysis demonstrates that gap junctions also mediate direct, bi-directional signalling between the soma and germline. When gap junctions between the soma and germline are disrupted, germline differentiation is blocked and germline stem cells are not maintained. In the soma, gap junctions are required to regulate proliferation and differentiation. Gap junctions are present between germline and somatic stem cells, as well as between differentiating cells by ultrastructural analysis. Localization and RNAi-mediated knockdown studies reveal that gap junctions in the fly testis are heterotypic channels containing Zpg (Inx4) and Inx2 in the germline and in the soma, respectively. Preliminary structure-function analysis of Zpg reveals that the C-terminus of the protein is essential for its function. Furthermore, gap junctions in the testis may be important for mediating calcium signalling. Overall, my results show that bi-directional gap junction-mediated signalling is essential to coordinate the soma and germline to ensure proper spermatogenesis in Drosophila. Moreover, I show that stem cell maintenance and differentiation in the testis are directed by gap junction-derived cues.
Medicine, Faculty of
Graduate

Abstract. This work defines a bi-directional visible light communication (VLC) testbed design and implementation process using Universal Software Radio Peripheral (USRP) software defined radios (SDR) and open-source software. The visible light communication design uses LED light sources for wireless communications purposes. The testbed combines light, infrared and radio frequencies as wireless media to be utilized in a hybrid wireless communication system. Bi-directional communication at 12.5 Mbps bit rate was successfully achieved and only limited by a sample rate of the USRP system. The achieved communication distance was in the range of 0.5 to 7 meters depending on the used optics. A TCP-IP communication and access to the Internet was also established by using light and infrared communication links. The Internet connection was also established by using power line communication for providing data to the lighting through the existing power line cables. The results in the work were obtained by using a GMSK modulation. Also, GFSK, QPSK, 8-PSK, 16-QAM and OFDM modulation were initially tested for future study.Kaksisuuntaisen näkyvän valon tiedonsiirtotestialustan suunnittelu ja toteutus. Tiivistelmä. Työssä suunnitellaan ja rakennetaan kaksisuuntainen kokeiluympäristö valon käyttöön langattomassa tiedonsiirrossa käyttäen ohjelmistoradioita ja avoimen lähdekoodin ohjelmistoja. Kokeiluympäristössä voidaan tutkia ja käyttää valon, Infrapunan ja radioaaltojen taajuusalueita tiedonsiirtoon. Valon tiedonsiirrossa käytetään valaistuskäyttöön suunniteltuja LED valaisimia sekä valaistukseen että tiedonsiirtoon. Työssä saavuttiin laitteiston näytteistystaajuuden rajoittama kaksisuuntainen 12,5 Mb/s tiedonsiirtonopeus ja käytetyn optiikan ominaisuuksista sekä tiedonsiirtonopeudesta riippuvainen tiedonsiirtoetäisyys 0,5–7 metriä. Järjestelmään ohjelmoitiin valo- ja infrapunalinkin avulla toimiva TCP-IP yhteys Internetiin. Internet yhteys valaisimelle onnistuttiin siirtämään myös käyttäen sähköverkon valmiita kaapelointeja. Työn tulokset saavuttiin käyttäen GMSK moduloitua signaalia. Myös GFSK, QPSK, 8-PSK, 16-QAM ja OFDM modulaatioiden toimivuus testattiin tutkimuksen jatkoa varten.

Thesis advisor: Celeste Wells
This study examined the influence of a popular Youtuber in creating social discourse surrounding concepts of health, fitness, and beauty, employing a case study approach of the popular Youtube channel, Blogilates. Both visual and rhetorical analyses were conducted on the titles and thumbnail images of the top 50 most viewed Blogilates videos, and 10 videos were studied in depth. The findings established the concept of a unique power relationship between Youtubers and their viewers, which also explains the marked dissonance between the discourse posited by the channel’s marketing and the discourse posited in the actual video content
Thesis (BA) — Boston College, 2017
Submitted to: Boston College. College of Arts and Sciences
Discipline: Departmental Honors
Discipline: Communication

We consider an asynchronous bi-directional relay network, consisting of two singleantenna transceivers and multiple single-antenna relays, where the transceiver-relay paths are subject to different relaying and/or propagation delays. Such a network can be viewed as a multipath channel which can cause inter-symbol-interference (ISI) in the signals received by the two transceivers. Hence, we model such a communication scheme as a frequency selective multipath channel which produces ISI at the two transceivers, when the data rates are relatively high. We study both multi- and single-carrier communication schemes in such networks. In a multi-carrier communication scheme, to tackle ISI, the transceivers employ an orthogonal frequency division multiplexing (OFDM) scheme to diagonalize the end-to-end channel. The relays use simple amplify-and-forward relaying, thereby materializing a distributed beamformer. For such a scheme, we propose two different algorithms, based on the max-min fair design approach, to calculate the subcarrier power loading at the transceivers as well as the relay beamforming weights. In a single-carrier communication, assuming a block transmission/reception scheme, block channel equalization is used at the both transceivers to combat the inter-blockinterference (IBI). Assuming a limited total transmit power budget, we minimize the total mean squared error (MSE) of the estimated received signals at the both transceivers by optimally obtaining the transceivers??? powers and the relay beamforming weight vector as well as the block channel equalizers at the two transceivers.

In recent years, the number of wireless nodes increases exponentially and the interference between the communication links is the major limiting factor in wireless communication networks. If the interference signals power is considerably weaker than the useful signal power, then the interference signals can be treated as noise. If the interference signals power is considerably stronger than the useful signal power, then first the useful signal can be treated as noise and the interference signals can be decoded. Secondly, the interference signals can be subtracted from the received signal and the useful signal can be decoded. However, often the interference signals are of similar power as the useful signal. In this case, conventionally the nodes perform transmission using orthogonal resources. If there are K nodes, then each node gets only 1/K of the total bandwidth. Recently, interference alignment (IA) has been developed as an efficient technique to handle interference signals, especially at high signal to noise ratio (SNR). In IA, the receiver space is divided into two subspaces, namely, the useful subspace and the interference subspace. Each node precodes its data streams such that at the intended receiver, all the interference signals align with each other within the interference subspace and the useful signal is in the interference-free useful subspace. Through IA, each node is able to get more than 1/K of the total bandwidth. However, to perform IA, often precoding over multiple time slots is necessary which introduces large delays in the system. Furthermore, global channel knowledge is necessary at all the nodes and no generalized closed form solutions to perform IA are available. In this thesis, it is shown how relays can be utilized to reduce the delay to two time slots, to perform IA with local channel state information at the nodes, and to obtain closed form solutions. In this thesis, the focus is on bi-directional communication. In contrast to the conventional use of relays, where the relays are used to improve the coverage, in this thesis, it is proposed to utilize the relays to manipulate the effective channel between the transmitters and the receivers in order to aid in the IA process. Q half-duplex relays with R antennas each aid in the bi-directional communication between K node pairs. Each node has N antennas and wants to transmit d data streams to its communication partner. For a bi-directional communication, two-way relaying is spectrally more efficient than one-way relaying and hence, two-way relaying is assumed as the underlying transmission protocol. It is assumed that the relays do not have enough antennas to spatially separate the data streams. It is derived that the relays need at least QR >= Kd antennas to aid in the IA process. Starting from this condition, depending on the number of relays and relay antennas, new algorithms to achieve IA are developed in this thesis. In terms of the sum rate achieved, IA is optimum at high SNR. For low and medium SNR, new algorithms to improve the sum rate performance are also developed in this thesis. First, a single relay is considered. It is shown that R >= Kd is a necessary condition to perform IA. Initially, the case when the relay has the minimum required number R = Kd of antennas is considered. IA in a two-way relay network is a trilinear problem because the transmit, the relay and the receive filters have to be jointly designed. Two new concepts, namely signal alignment (SA) and channel alignment (CA), are proposed to decouple the design of the transmit and the receive filters, respectively, from the design of the relay filter. SA is the process through which the signals from the nodes align pair-wise at the relay. CA is the process of alignment of the effective channel including the channel between the relay and the receiver and the receive filter with the effective channel of its communication partner. It is shown that SA and CA are necessary steps to achieve IA. Thereby, the process of IA is decomposed into three linear steps, namely, SA, CA, and zero forcing (ZF). The number of antennas required at the nodes to perform SA and CA is derived. A closed form solution to achieve SA, CA, and ZF is proposed. It will be shown that, for the special case R = Kd, pair-wise channel knowledge at the nodes and global channel knowledge at the relays are sufficient to perform IA. Then, the case R >= Kd is considered. Now the relays have more antennas compared to the first case. New algorithms to use the additional antennas either to increase the number of interference free data streams defined as degrees of freedom or to reduce the minimum required number of antennas at the nodes to perform SA and CA have been proposed. For this purpose, SA and CA are generalized and new concepts namely, partial signal alignment (PSA) and partial channel alignment (PCA) are proposed. It is shown that IA is achieved through PSA, PCA, and ZF. In order to investigate how many antennas are needed at the nodes and at the relay to achieve IA, the properness conditions for the solvability of the IA equations are derived. If the number of variables is larger than or equal to the number of equations in the system, then the system is classified as proper, else as improper. It is shown that the derived properness condition is the generalization of the condition on the number of node antennas derived for the case R = Kd. PSA and PCA are bilinear problems. An iterative algorithm to perform PSA and PCA is proposed. Also, for a special case for which the conditions are given in this thesis, a closed form solution is also proposed. The sum rate achieved by the proposed IA algorithm is compared with a reference algorithm without IA. It is shown that the proposed IA algorithm has better sum rate than the reference algorithm at high SNR. Secondly, multiple relays are considered. It is shown that QR >= Kd is a necessary condition to perform IA. Initially, the case QR = Kd is investigated. In this case, the concepts of SA and CA developed for the single relay scenario are extended to the multiple relay scenario. However, in multiple relay case, the relays do not share their received signals i.e., the signal received at one relay is not available at other relays. Hence, the relay processing matrix is a block diagonal matrix. Therefore, ZF cannot be performed as in the single relay case. A new method named cooperative zero forcing (CZF) is proposed for this case. In CZF, the nodes cooperate with the relays and choose their SA and CA directions such that the relays can perform ZF with a block diagonal matrix. The properness condition is derived. It is shown that the derived properness condition is a generalization of the expression derived for the single relay case with Q = 1. An iterative algorithm to achieve IA is proposed. Then, the case QR >= Kd is considered. It is shown that the generalization of PSA to multiple relays leads to a quad-linear problem and therefore, does not simplify the trilinear IA problem. Hence, a new iterative IA scheme is proposed. The properness condition is derived. An iterative algorithm to achieve IA is proposed. During each iteration, each of the transmit, the relay and the receive filters are designed one after another while keeping the other filters fixed. The sum rate performance of the proposed IA algorithms are compared with the reference algorithm without IA and it is shown that the proposed IA algorithm achieves better sum rate than the reference algorithm at high SNR. Finally, for all the scenarios considered above, interference management schemes which consider not only the interference signals but also the useful signals are proposed. IA is optimum at high SNR. At high SNR, noise is almost zero and the interference signals are the only limiting factor. IA completely suppresses the interference signals and is optimum at high SNR and, hence, achieves higher sum rate than the reference algorithms at high SNR. However, at low and medium SNR, where the noise plays a significant role, it is beneficial to improve the useful signal power in comparison to the noise power. In this thesis, two algorithms are proposed to improve the sum rate performance at low and medium SNR. The first algorithm is based on IA. In this algorithm, the objective is as follows: out of all the available IA solutions, the one that maximizes the SNR is chosen. This algorithm is applicable whenever the IA solutions are obtained in closed form. A gradient based algorithm to find at least a local maximum is proposed. The second algorithm is based on minimization of the mean squared error between the transmitted and the estimated data symbols subject to the node power constraints and relay power constraint. An iterative algorithm to find at least a local minimum has been proposed. Through simulations it is shown that these two algorithms have better sum rate performance than the reference algorithm and the IA algorithms at low and medium SNR.

碩士
國立雲林科技大學
電機工程系碩士班
90
There are three topics that are studied in this thesis. In the first topic, we emphasize on the so-called synchronization. By the Lyapunov stability theorem, a state feedback gain can be designed to guarantee the synchronization between the master and slave chaotic systems. In the second topic, the concept of the cryptology is used to enhance the performance of security in the communication by the chaotic circuits. In the third topic , we studied how to design an adative controller for hyperchaotic circuits with unknown parameters. By using the concepts of PR or hyper-minimum-phase, the adaptive controller and adaptive law can be designed. Further- more, the concepts cryptography and adaptive control law are combined to design an adaptive cryptosystem. Finally, some numerical simulations and the fabrication of the chaotic circuits were given to demonstrate the efficiency of the proposed scheme.

碩士
國立成功大學
醫學工程研究所
91
With the advances in microelectronics, micromachining, biomaterials, and biocompatible package technology, many sensing devices can be fabricated in a miniaturized way. Various implantable sensing device modules have been developed as biological signal monitoring systems for various clinical researches in recent years. The aim of this study is to develop a wireless power and bi-directional data transmission for implantable sensing device systems. The proposed implantable sensing device takes the full advantages of wireless transmission features, including wireless transfer of power and data between the implant and an external unit. The implant receives the desirable command from external transmitter to determine the sampling rate and channel of implanted sensing module. For recording biological signals, we used differential mode instrumentation amplifier and operation amplifier to acquire the biosignals. The biological signals after differential amplification were send to analog-to-digital converter (ADC) from which and the digital data were transmitted outwards by using a passive RF telemetry link. For read-out transmission, a load shift key (LSK) approach, which allows wireless power and data transmission through the same RF link, is used in this study. We have successfully designed, implemented and tested all the functional blocks of a bi-directional implantable sensing device system. With appropriate tuning of the class-E power amplifier and modulation index, the maximal read-out transmission rate can reach around 125 kbps when the distance between the transmitter coil and receiver coil is within 4.5 cm. Within this transmission distance, lateral displacement of receiver coil is allowed as long as it is inside the area of transmitting coil. The overall implantable sensing device including the RF interface circuitry dissipates 70 mW of power from a 3-V supply and occupies 20×40 mm2 of area. This prototype of implantable sensing device has been validated in acute animal experiment and can be utilized for varied implanted applications after biocompatible packing.

碩士
中原大學
電機工程研究所
97
Network coding is a technique which allows intermediate nodes to encode the input data before broadcasting the information to other neighbors. Compared with traditional network transmission, it can improve the throughput and reliability of transmission. On the other hand, in order to improve the performances of wireless transmission, Alamouti space-time block code is also widely used. It uses multiple antennas to transmit messages simultaneously to achieve better performances. In 2008, Chau Yuen, etc., proposed a scheme which combines network coding with space-time code to improve the performances of transmission in bi-directional wireless communication. They analyze Amplify-and-Forward (AF) and Decode-and-Forward (DF) methods with and without channel state information (CSI). The simulations are based on schemes which have two antennas at the relay, and a single antenna at the source and destination. In this thesis, we make a further analysis and discussion based on Chau Yuen's scheme. We study the schemes which have three or four antennas at the relay. According to our simulations, we conclude that by using multi-antennas in Decode-and-Forward (DF) case, the transmission performances can be further improved.

碩士
國立成功大學
醫學工程研究所碩博士班
90
Various implantable bio-microsystems have been designed for the neural prostheses and other clinical studies. For the implantable bio-microsystem, power is one of the major concerns in the system design. Due to the lifetime limitation, battery is not the optimal choice in the implanted devices. In recent years, electromagnetic propagation through inductive coupling links has been commonly used to deliver power and information into these implantable bio-microssytems. Another issue is the outward transmission of sensing data, which requires an internal data transmission system with the power acquired from the external controller. The aim of this study is to investigate the functional blocks needed for a wireless bi-directional transmission micro-stimulator and present their simulation results. This implantable device includes internal RF front-end circuit, control circuit, stimulator, and on-chip transmitter. The operation of this system is to receive an AM modulated 2MHz signal generated by external circuits. This signal includes the power and data necessary for the whole internal circuits. Through the internal circuits, a stable DC voltage and digital data can be extracted for neuromuscular stimulation. Besides, the system can acquire the biological sensing signal for on-chip transmission. In this study, most of the functional blocks for the implantable device can be verified by using Hspice according to the design rules of TSMC 0.25 um CMOS process. Our simulating results show that the RF front-end circuits can provide a stable 2.5V DC voltage and extract digital data accurately. Meanwhile, in the signal process circuits, the preamplifier can provide a stable gain for bio-signals (about 40dB to 60dB). The bandpass filter with bandwidth between 250Hz to 5KHz filter circuit is designed with ladder type approach. Finally, an accurate A/D data converter with 8-bitresoultion of successive approximation register (SAR) has been verified too. All the simulating results can be a base for future fabrication of implantable devices.

碩士
國立交通大學
光電工程所
89
From the coupled-wave theory, it is obvious that the diffraction efficiency of a reflection-type volume hologram depends on the thickness, the average refraction index, the modulation refraction index of the recording material, and the reconstructed wavelength. Under optimal conditions, a reflection volume holographic element with maximum diffraction efficiency for a chosen wavelength, and minimum diffraction efficiency for another chosen wavelength is designed. Consequently, it can be used as a bi-directional wavelength-division multiplexer/demultiplexer (BIDI WDM) for optical communications. In order to demonstrate its feasibility, silver halide emulsions with a 5.7 m thickness and a diode-pumped solid-state laser with a 532nm wavelength are used. For experimental conveniences, 532nm and 632.8nm are chosen as two reconstructed wavelengths. Firstly, the average refraction index and the modulation refraction index of the silver halide emulsions with various exposures are measured with these reconstructed wavelengths. And their relation curves are depicted. Based on these results, the optimal exposures and its corresponding average refraction index and modulation refraction index can be obtained. Since this element is designed for BIDI WDM, any of the incident angle, the reflected angle and the diffracted angle equals 45o. Substituting these conditions into K-vector diagram, the recording geometry can be derived. Finally, an element is fabricated with the derived recording geometry and the optimal exposure. Its performance is estimated that it has transmission rates 3.979 dB and 1.549 dB for wavelengths 532nm and 632.8nm, respectively. And the elements for 1.3/1.55 m can be fabricated similarly.

In today’s wireless communication systems, usually the point-to-point transmission technique is used for the transmission between two nodes S1 and S2. If a point-topoint transmission between S1 and S2 is not possible, e.g., due to shadowing or limited transmit powers, two-hop relaying is a promising technique, in which the transmission between S1 and S2 is assisted by an intermediate relay station (RS). In this thesis, non-regenerative two-hop relaying is considered which means that the received signals at the RS are neither decoded nor re-encoded, but only linear signal processing (SP) is employed at the RS. Just recently, two-hop relaying has been investigated in conjunction with multiple-antenna techniques which promises significant performance gains in terms of achievable data rates. In this work, multiple antennas are used at S1, S2 and the RS in order to perform spatial multiplexing by adaptive beamforming (BF). This thesis investigates two different two-hop relaying schemes for bi-directional transmission between S1 and S2, namely one-way and two-way relaying. In one-way relaying due to the half-duplex constraint, one time slot is required for the first hop transmission from S1 to the RS, and another time slot is required for the second hop transmission from the RS to S2. For bi-directional transmission, another two time slots are required for the transmission from S2 via the RS to S1 resulting in a requirement of four time slots in total. Thus, compared to a bi-directional point-to-point transmission between S1 and S2, which requires only one time slot for the transmission from S1 to S2 and another time slot for the transmission from S2 to S1, the number of required time slots is doubled in one-way relaying. In case of bi-directional transmission, the recently proposed two-way relaying scheme is a very promising scheme in terms of resource efficiency since it requires only two time slots. In two-way relaying, S1 and S2 transmit their signals simultaneously in the first time slot to the RS which retransmits a superposition of the signals of S1 and S2 in the second time slot. Thus, the received signal at each node contains the signal which has been transmitted by the respective receive node itself. If sufficient channel state information (CSI) is available at the receive node, it can determine the desired signal by subtracting the own transmitted signal. This subtraction is termed cancellation of duplex interference (CDI). In this work, a unified system model for one-way and two-way relaying is developed. For both relaying schemes, it is of particular interest how the sum rate of the system can be maximized by adaptive BF. The achievable sum rates depend considerably on the system capabilities, which are defined by the CSI availability and the SP capabilities at S1, S2 and the RS. Since the system capabilities influence the applicable adaptive BF algorithms, novel sum rate maximization problems are identified and classified by a framework consisting of four different cases of system capabilities: • A system with full capabilities, in which S1 and S2 perform adaptive BF and CDI, and the RS performs adaptive BF. • A system with limited capabilities at the RS, in which only S1 and S2 perform adaptive BF and CDI. • A system with limited capabilities at S1 and S2, in which only the RS performs adaptive BF. • A system with local CSI at S1 and S2, in which S1 and S2 perform CDI, and only the RS performs adaptive BF. The different cases are considered for one-way and two-way relaying, and the respective maximum sum rates are determined. In one-way relaying, an analytical BF algorithm for maximizing the sum rate in the system with full capabilities is reviewed. For the other new cases of system capabilities in one-way and two-way relaying, numerical solutions to the sum rate maximization problems are given. For the systems with limited capabilities at the RS in one-way and two-way relaying, new sub-optimum analytical BF algorithms with close-to-optimum performances are proposed. It is shown that the maximum spatial multiplexing gain corresponds to the minimum of the number of antennas at the RS and the number of antennas at S1 and S2 in one-way relaying, and to the minimum of the number of antennas at the RS and twice the number of antennas at S1 and S2 in two-way relaying. Furthermore, it is demonstrated that the sum rate in two-way relaying is almost twice as high as the sum rate in one-way relaying. Beside the adaptive BF algorithms maximizing the sum rate, other adaptive BF algorithms minimizing the mean square error (MSE), minimizing the MSE under the zero forcing constraint, and maximizing the signal-to-noise ratio are known to provide reasonable performance in point-to-point transmission. Since adaptive BF only performed at nodes S1 and S2 has already been investigated in several works regarding point-to-point transmission, in this thesis special attention is paid to the recent field of systems in which adaptive BF is only performed at the RS. For such systems in one-way as well as in two-way relaying, the aforementioned optimization problems, are newly formulated, solved, and analyzed. Promising performance results are especially obtained by the adaptive BF algorithm minimizing the MSE. In order to obtain CSI in the different cases of system capabilities, novel pilot transmission schemes and the respective channel estimation algorithms are developed. Furthermore, the impact of imperfect CSI on the performance of two-way relaying is considered. Finally, two scenarios with multiple nodes are introduced exemplarily in order to give a first insight into the problems arising from multiple access in two-way relaying.

碩士
國立中正大學
電機工程研究所
99
This thesis presents design and implementation of the controller peripheral and communication interface of a three-phase bi-directional inverter system, which will be applied to a dc microgrid. Based on the basic concept of smart grid, peripheral and communication interfaces of a bi-directional inverter system using two microcontrollers RX62T are established. By considering further expansion, three fully developed communication interfaces, I2C, UART and SPI, are chosen, and their structure, communication principle and characteristics are analyzed and compared. In order to obtain power information and allow users to understand system operation, this study selects FRAM and SD card as memory, and Timer and LCD module as peripheral, to illustrate the communication principle and hardware architecture. Finally, this study designs the driver of peripheral and communication interfaces, which are combined with three-phase bi-directional inverter circuits to verify its correctness and feasibility.

碩士
國立中正大學
電機工程研究所
99
This thesis presents design and implementation of the controller peripheral and communication interface of a single-phase bi-directional inverter system, which is applied to a PV dc power distribution system. Based on the concept of constructing a smart grid, two microcontrollers TMS320LF2406A are adopted to realize the controller peripheral and communication interface for a single-phase bi-directional inverter system. Based on the SCI protocol combined with ZigBee or Bluetooth wireless module to achieve remote monitoring, and the SPI protocol to implement synchronous communication between the two microcontrollers, the communication principle and structure are analyzed and compared. In order to access the related information any time, an EEPROM is used as an external memory, and LCM is combined with the MPPT to display its dynamic information. Finally, the peripheral and communication interfaces combined with a single-phase bi-directional inverter were designed and implemented to verify its feasibility and accuracy.

碩士
國立臺北科技大學
自動化科技研究所
90
This thesis develops a bi-directional remote control and monitoring system for home and office automation based on the wireless communication protocols including FLEX paging, Bluetooth, and GSM short message service (GSM SMS). In the remote control unit, the control command can be sent through either the FLEX channel or the GSM SMS provided by the GSM Module in accordance with the channel condition and communication expense. For receiving the FLEX control signals, an 8051 microprocessor-based remote controller embedded in the wireless server is implemented with a decoding scheme derived by the induction method. The remote monitoring is accomplished by informing the user the IAs’ control statuses via the GSM SMS, thereby completing the bi-directional function. To escape from the fetters of the interconnection wires, an indoor wireless communication network is established by applying Bluetooth technology. This way the message can be exchanged wirelessly between the controlled IAs and server system. Since multimedia service is one of the killer applications in the 3G wireless communications, we have also added video capability to our platform, which transmits the video of the controlled IAs to the users for monitoring. The transmitted video is compressed using the international standard H.263 video codec to achieve a very low bit rate transmission. Due to the current limited capacity of GSM system, we have not transmitted the video via GSM channel to a cellular device but rather have simulated this via the Internet to the PC terminal. However, the prototype can easily migrate to a cellular device once the 3G wideband CDMA infrastructure matures. Finally, a series of experiments are conducted where an electric fan is adopted as a control target. Experimental results verify the effectiveness of this system. This system is operated with high mobility and low communication expense and thus can be popularized easily. We expect that communication businesses will enhance their competitiveness in the mobile marketplace if they choose to apply the services suggested by this study.