Proceedings of the IEEK Conference (대한전자공학회:학술대회논문집)
The Institute of Electronics and Information Engineers (IEIE)
- 기타
2003.11c
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Crosstalk among telephone lines in the same bundles is a major impairment in current VDSL systems. In this paper, we analysis the crosstalk effect of DSL using different frequency band upon ANSI standard VDSL systems. Simulation results show that data rate of ANSI VDSL decrease by crosstalk from another VDSL using different frequency. This study has the potential implication and benefit for ANSI standard DMT VDSL energy distribution in subchannel
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VDSL(Very-high-rate Digital subscriber Line) have a severe FEXT(Far-End Crosstalk). This paper proposes FEXT cancelation scheme in VDSL system. The scheme is GDFE(Generalize Decision Feedback Equalizer) and Vectored-DMT (Discrete Multitone). Feedback part of GDFE decreases FEXT noise. Canceler and Precoder block a part of Vectored-DMT eliminate FEXT. After all, simulation result show improvement of transmit and receive speed.
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10GBASE-T is 10Gigabit Ethernet over horizontal structured, twisted-pair copper cabling.(1) It aims to transmit data at a speed of 10Gbps at a l00m distance away, through UTP (unshielded twisted -pair) Cat-5e cable 4-pair. This paper looks over the characteristic of media over Cat 5e, 6, 7, and then suggests how much noise should be removed from it in order to offer the transmission speed of 10Gbps as sending data through each physical medium.
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In this paper, the bit error rate (BER) performance of the fast frequency hopping/M-ary frequency shift keying system using the clipper receiver is analyzed by using the characteristic function (CF) technique in the presence of n=1 band multitone jamming and additive white Gaussian noise environment. The CFs of the clipper receiver outputs are derived as a infinite series representation using Gamma function and Marcum's Q -function. The analytical results are validated with various simulation results. Performance comparisons with linear combining receiver are shown that the BER performance of the clipper receiver is much better than that of the linear combining receiver In addition, as the clipping level approaches to infinity, it is shown that the clipper receiver simply performs a linear combining without clipping and there exists an optimum value of diversity level (the number of hops per symbol) that maximizes the worst case BER performance of the clipper receiver.
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A reduced-state sequence estimation(RSSE) for trellis-coded (TC) 8PSK/cyclic prefixed single carrier(CPSC) with minimum mean-square error-liner equalization(MMSE-LE) on frequency-selective Rayleigh fading channels is proposed. The Viterbi algorithm (VA) is used to search for the best path through the reduced-state trellis combined equalization and TCM decoding. The symbol error probability of the proposed scheme is confirmed by computer simulation.
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Radiofrequency ablation (RFA) as one of the microwave hyperthermia is becoming the treatment of choice for small but inoperable tumors of the liver. In this paper, we designed the applicator composed of semi-rigid coaxial cable antenna with a ring slot for RFA. To optimize the maximum output of radiation with omni direction at 2450 ㎒, we simulated the applicator using Electromagnetic simulation program and analyzed the return loss and the electric field E
$\_$ tot/ at the near-field region between the simulation results and measurement results. As a result, we obtained the return loss of -29.786 dB at 2450 ㎒ when the applicator was placed between two blocks of a pig's liver, and the measurement results agreed with the simulation results well. Therefore, this applicator using semi-rigid coaxial cable antenna with a ring slot can be used very usefully as the applicator for RFA. -
In this paper, it proposes the efficient iterative decoding stop criterion using the variance value of LLR. It is verifying that the proposal iterative de-coding stop criterion can be reduced the average iterative decoding number. The proposal algorithm md hardware synthesize to use the Synopsys Tool, performance validations perform through the ModelSim.
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In this work, we have designed a fully integrated 2.4GHz LC-tuned voltage-controlled oscillator (VCO) with multiple tuning inputs for a 0.25-
$\mu\textrm{m}$ standard CMOS process. The design of voltage-controlled oscillator is based on an LC-resonator with a spiral inductor of octagonal type and pMOS-varactors. Only two metal layer have been used in the designed inductor. The frequency tuning is achieved by using parallel pMOS transistors as varactors and back-gate tuned pMOS transistors in an active region. Coarse tuning is achieved by using 3-bit pMOS-varactors and fine tuning is performed by using back-gate tuned pMOS transistors in the active region. When 3-bit digital and analog inputs are applied to the designed circuits, voltage-controlled oscillator shows the tuning feature of frequency range between 2.3 GHz and 2.64 GHz. At the power supply voltage of 2.5 V, phase noise is -128dBc/Hz at 3MHz offset from the carrier. Total power dissipation is 7.5 mW. -
The 1.63㎓, 2.33㎓ dual-band PLL frequency synthesizer has been developed for applications to the miniature repeater. The miniature dual-band repeater will be used at shopping mall, basements and underground parking lots. The in-loop 1.63㎓, 2.33㎓ dual-band PLL frequency synthesizer has been developed by designing Si BJT VCO and PLL loop circuits with Colpitts. The prototype of 1.63㎓, 2.33㎓ dual-band PLL frequency synthesizer of size 19
${\times}$ 19${\times}$ 8(mm) has shown operating frequencies of 1.63㎓, 2.33㎓ ranges, RF output of 1dBm(PCS), 1dBm(IMT-2000), phase noise of -100 dBc/Hz(PCS), -95dBc/Hz(IMT-2000) at 10KHz offset, harmonics suppression of -24dB c(PCS), -15dBc(IMT-2000). -
Generally, the frequency of set makes ICI and degrades OPDM system performance. Thus, we propose a pulse shaped OFDM to give robustness against the frequency offset. The proposed OFDM system uses pulse shaping with smooth shape, instead of rectangular pulse shape, to reduce the power of ICI. The proposed scheme always gives performance gain in comparing with the convention one, when the frequency offset exists. In addition, the smoother pulse shape is employed in the proposed system, the more performance gain is obtained.
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This paper describes the design and implementation of a HNCP-UPnP bridge. HNCP networked devices targeted to white goods are allowed to be controlled and monitored by UPnP Control Point. Bridge provides automated creation of UPnP proxy device and message conversion. The developed system enables integration of heterogeneous home network.
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This paper describes the design and implementation of HNCP bundle in the OSGi framework targeted to the home network system. The developed home network system is composed of a home server and several networked home appliances, and is connected via residential gateway to the external access network. The developed HNCP bundle allows a user to control and monitor home appliances in HNCP domain. We show the feasibility of the implemented HNCP bundle in the OSGi framework.
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In this paper, we estimate the performance requirements of general-purpose DSP for Carrier Recovery of OFDM DVB-T receiver. Firstly, we transported the designed fixed-point OFDM DVB-T model to a floating-point software model written in C. Then, we measured the number of instruction cycles required for operation of Carrier Recovery in time. We use SignalMaster
$\^$ TM/ DSP platform of LYRtech Inc. as a environment of estimation, and Simulink$\^$ TM/ as a graphical interface, Code Composer StudioTM of TI as profiler and compiler, and SPW$\^$ TM/ for presenting functional reliability and comparing the performance distortion with fixed-point model. As a result, we show the required number of DSPs in our DSP-based system, and introduce the need of Multi-DSP-based system. -
This paper describes the design and the simulation of a V-band single pole double throw (SPDT) FET switch fur millimeter-wave applications using drain impedance transformation network with CPW transmission line. The designed switch has about 10% bandwidth at 60GHz. Insertion loss is better than 3dB fur the ON state and Isolation is larger than 30dB fer the OFF state. The maximum isolation is 43.4dB at 60GHz with input power of 10dBm. The yield analysis is done considering the effects of pHEMT variations.
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This paper presents the design of dual-band VCO using PBG structure for IEEE 802.11A/B. By adding switch circuit to the single-band VCO, we could achieve a dual-band VCO. The center frequencies of dual-band VCO are 5.93GHz(-13dBm) and 2.37GHz (3.50dBm). The phase noise is improved about l0dB by using PBG Structure.
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An output multiplexer of manifold type is widely employed in a recent satellite transponder due to its small size and mass. For correct operation, channel fillers in manifold multiplexer must be singly terminated. In this paper, a simple synthesis method fur a single terminated filter is described. From the given method, a 4-pole singly terminated elliptic function filter for Ka band satellite transponder is designed. The filter is shown to be suitable for satellite application and its measured results agrees well with computed ones.
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In this paper, active frequency doubler with broadband characteristics and unconditional stability from 6GHz to 12GHz was designed and fabricated using PHEMT. The designed frequency multiplier has a bias point near pinch-off and a proposed RC circuit between bias line and input matching network for the improvement of stability. With 0dBm input power, second harmonic of 1.7dBm at 12GHz, - 27.5dBc suppression of 6GHz fundamental, -18dBc suppression of 18GHz 3rd harmonic and the output bandwidth of 1.8GHz have been measured.
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We design the local oscillator system of the 100 GHz band radio receiving system for a cosmic radio observation. We use the YIG oscillator with digital driver which is the main oscillator. This oscillator has a good frequency and phase stability at some temperature variation, and the easy computer aided control characteristics. This total system designed to two subsystem, first is the oscillator system include YIG oscillator, tripler, harmonic mixer and triplexer etc., second is the PLL system to supply the precise and stable local oscillator frequency to mixer. The proposed local oscillator system in this paper can be use a single or multi pixel receiver because this system can be lock the local oscillator frequency automatically using PC.
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The Bi-directional Wireless Capsule endoscope con sists of CMOS Image sensor, FPGA, LED, Battery, DC to DC Converter, Transmitter, Receiver and Antennas. The RF transmitter at 1.2GHz range is designed and fabricated with 10 mm(diameter)x1.6 mm(thickness) dimension considering the maximum permission exposure(MPE), system size, power consumption, linearity and modulation method. The fabricated RF receiver at 400MHz range can demodulate the external signals so as to control the behavior of CMOS image sensor. four LEDs and Transmitter.
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In this paper, Self-Oscillating Mixer is designed by oscillator that was based on a general nonlinear input-output model for the subharmonic injection locked oscillator is analysed. We have designed and fabricated the Self-Oscillating Mixer for 5GHz by proposed subharmonic injection locked oscillator based frequency synthesizer structure that have characteristic of good frequency sensitivity, good phase noise. The design strategy leading to an optimized SILO with regards to its locking range is described and a test SOM circuit is demonstrated a 4dB conversion gain at 280MHz IF frequency from the carrier.
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In this paper, we analyze the concept of network convergence and characteristics of Broadband convergence Network(BcN) from the service perspective where convergence would appear. We suggest the evolutionary 3 stage steps of BcN as an ideal network strategy when considering present network situation. We also propose the features of several representative services that are expected to emerge out of network convergence.
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This paper propose a simple and efficient scheme to deliver frames between TDM interfaces and IP interfaces in NGTSs. Next Generation Transport Systems (NGTSs) are new conceptual transmission equipments fur next generation network. They consist of TDM interfaces and IP interfaces. NGTSs are suitable fur high-speed transmission links such as SONET/SDH and Gigabit Ethernet. The proposed VLAN scheme for NGTSs is implemented successfully.
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As optical network technology advances, the Dense-Wavelength Division Multiplexing(DWDM) networks have been widely accepted as a promising approach to the Next Generation Optical Internet (NGOI) backbone networks. Especially. a fault/attack management scheme in NGOI backbone networks is one of the most important issues because a short service disruption in DWDM networks carrying extremely high data rates causes loss of vast traffic volumes. In this paper, we suggest a fault/attack management model for NGOI backbone networks and propose a fault/attack recovery procedure in IP/GMPLS over DWDM.
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In the next generation backbone networks based on dense-wavelength division multiplexing (DWDM), the routing and wavelength assignment with quality-of-service (QoS) recovery is essentially needed to support a wide range of communication-intensive and real-time multimedia services. This paper proposes a new dpmic routing method called as MW-MIPR (MultiWavelength-Minimum Interference Path Routing), which chooses a route that does not interfere too much with many potential future connection requests. This paper also proposes a differentiated RWA mechanisms combined with MW-MIPR algorithm to provide QoS recovery for various multimedia applications in the next generation backbone networks based on DWDM.
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Wavelength division multiplexing technology is a promising solution for the next generation optical networks. Optical buffer is a key component for optical packet switching system. It can be used to hold optical packets and to resolve the contention of optical packets. In this paper, we implemented a optical buffer using optical wavelength converters and demonstrated that optical packets are delayed successfully.
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In this paper, we propose a dynamic parallel channel allocation mechanism that dynamically controls total number of allocation channels of each subscriber to effectively service user bandwidth demands while high utilization and fairness are guaranteed in WDM based optical access networks. The logical performance gain of statistical multiplexing by dynamic channel allocation is validated with analytic method as well as simulations. We also introduce the adaptive padding scheme in order to efficiently distribute forwarded frames to aggregated multi-link channels which are formed by parallel channel allocation mechanism. The proposed scheme shows the performance enhancement by minimizing unnecessary padding size and the processing time.
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PON (Passive Optical Network) is an emerging local subscriber access architecture that provides more bandwidth and services to subscriber than DSL (Digital Subscriber Line and HFC (Hybrid-Fiber Coaxial) network. A PON is a point-to-multipoint optical network with no active elements in the signals' path from source to destination. Advantages of using PON for a subscriber access network include large coverage area, reduced fiber deployment, multicast and broadcast capabilities, reduced cost of maintenance (due to devices being passive), and ease of upgrades to higher bit rate or additional wavelengths. PON uses WDM (Wavelength Division Multiplexing) technique that transmits the downstream and upstream data at each different wavelength. For transmitting the CATV (Community Antenna television) service through PON network, we give out additional wavelength. This study shows the available TPS (Triple play service) architecture using CATV overlay EPON (Ethernet PON) architecture and analyzes the effects of EPON-based CATV transmission by measuring the power loss fur each wavelength and the power range of the available analog wavelength and RF.
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Passive optical networks (PONs) will be the pervasive choice in the design of next-generation access networks. One possible solution to implementing Passive optical access network is to rely on wavelength-division multiplexing (WDM). In this paper, we solve the problem of providing real-time service to both hard and soft real-time messages in conjunction with a conventional vest-effort service in WDM. we propose an adaptive scheduling algorithm to schedule and manage the message transmissions in the optical access network. Proposed algorithm is MLF-MQF. Also, we suggest dynamic bandwidth algorithm(DBA) in Loop-back WDM-PON (LPB-PON).our mechanism based on bandwidth reservation protocol.
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In this paper, we propose a dynamic key lifetime change protocol for performance enhancement of virtual private networks using IPSec. The proposed protocol changes the key lifetime according to the number of secure tunnels. The proposed protocol is implemented with Linux 2.4.18 and FreeS/WAN 1.99. The system employing our proposed protocol performs better than the original version in terms of network performance and security.
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This paper proposes a performance analysis model of security sowers. Performance analysis of security server reflects both the session and data traffic load. The proposed model is the bases of estimating the maximum response time and minimum queue size of a security server comprising a session association processor whose throughput is 1000 connection/s.
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Sensor networks consist of sensor nodes with small-size, low-cost, low-power, and multi-functions to sense, to process and to communicate. Minimizing power consumption of sensors is an important issue in sensor networks due to limited power in sensor networks. Clustering is an efficient way to reduce data flow in sensor networks and to maintain less routing information. In this paper, we propose a multi-hop clustering mechanism using global and local ID to reduce transmission power consumption and an efficient routing method for improved data fusion and transmission.
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A sensor network consists of many low-cost, low-power, and multi-functional sensor nodes. One of most important issues in of sensor networks is to increase network lifetime, and there have been researches on the problem. In this paper, we propose a routing mechanism to prolong network lifetime, in which each node adjusts its transmission power to send data to its neighbors. We model the energy efficient routing with power control and present an algorithm to obtain the optimal flow solution for maximum network lifetime. Then, we derive an upper bound on the network lifetime for specific network topologies.
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A lot of institutes have proposed RMT (Reliable Multicast Transport) techniques over IP multicast environment which provides only best-effort services. The ECTP (Enhanced Communications Transport Protocol) is a kind of RMT technique and an international standard of ITU-T and JTC1/SC6. It is a protocol that provides reliability fer IP multicast environment. In this paper, we tested ECTP applications which are MFTP (Multicast file transport protocol) and WB (white Board) on the APAN (Asia-Pacific Advanced Network) with the Kyushu University in Japan. We measured ECTP traffic using a packet capture tool that programmed by Pcap library that is developed in Lawrence Berkeley institute. In according to the result, we think that ECTP is an efficient protocol in transporting files to many receivers simultaneously.
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In this paper, we propose a scheme that applies to the VoIP application based on H.323 protocol to enhance the bandwidth efficiency. We multiplex the audio and video stream. In this scheme, audio frame is carried with video stream. And we applies not only multiplexing but also (in header compressing to the real audio/video stream to increase the bandwidth efficiency. With the multiplexing and RTP header compressing, we gain the bandwidth efficiency. In the finite network environment, We can assign bandwidth to other users who want to use other service. and other VoIP users. If we can apply the real time network situation to the our VoIP application, we can get more efficient performance.
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In this paper, we propose QoS guarantee system fur multi-functional VoIP end Terminal. This system guarantees low delay of voice data for Internet telephony in VoIP end terminal that has various kinds of Internet dependant application. QoS system we propose support low delay transmission in VoIP terminal interface.
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IEEE 802.11a Distributed Coordination Function(DCF) Protocol을 사용하여 Real-Time MultiMedia Data의 전송을 수행할 경우, DCF Protocol의 적합하지 못한 Mechanism에 의하여, Data 전송의 극대화를 이루지 못한다. Retransmission이 반복되는 경우, Binary Slotted Exponential Backoff Mechanism은 거대한 Packet Delay와 Jitter의 원인이 되며 Automatic Repeat Request(ARQ) 방식의 Ack Mechanism은 MultiMedia Data를 전송하기에 적합하지 못하다. 본 논문은 위와 같은 문제점을 해결하기 위하여 Real-Time MultiMedia Data을 주로 전송하는 STA에 따른 Real-Time/Non-Real-Time(RT/NRT) Station(STA)의 구분과 보내고자 하는 Real-Time MultiMedia Data의 Network Traffic Load(The Required Bandwidth)를 고려하여, Modified DCF(mDCF) Protocol의 Modified Backoff(mBackOff), Modified BlockAck(mBlockAck) Mechanism을 제시함으로서, Data 전송의 극대화를 제공하며, 또한 IEEE 802.11a와의 호환성을 제공한다.
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In this paper, we aim to communicate wirelessly as appling the Bluetooth technology to the VoIP system, and we select the embedded system which can be guaranteed performance and economical efficiency for implementation that system. So we implemented embedded Bluetooth AP and embedded VoIP system based on Bluetooth. For voice quality improvement in the implemented system, the Bluetooth ACL link and the appropriate Bluetooth packet was selected. Also, it was designed about the handling method of voice packet by using variable jitter buffer and then tested on embedded VoIP system based on Bluetooth.
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IEEE 802.16 Wireless MAN standard specifies the air interface of fixed point-to-multipoint broadband wireless access systems providing multiple services. Among the service classes supported by the wireless MAN, the best effort service class is ranked on the lowest position in priority and is assisted by a MAC scheme based on reservation ALOHL Such MAC scheme must include a number of components, while many of them are not specified in the standard. In this paper, we thus reveal main components of a MAC scheme supporting the best effort service and present candidate schemes implementing such components. Combining schemes for implementing components, we then construct distinctive MAC schemes supporting best effort service. In designing a MAC scheme, the delay performance induced by the scheme should be considered since scarce resource may be available for the best effort service after the preemptive resource occupation by other service classes. In this paper, we focus on the delay fairness among the subscriber stations using the best effort service. For evaluating a MAC scheme in delay fairness, we present two definitions of delay fairness and provide a criterion for optimal MAC scheme according to each definition of delay fairness. Using a simulation method we investigate the mean delay performance exhibited by each MAC scheme arid find an optimal scheme in delay fairness. From numerical examples, we observe that SR/ED/PG+P scheme has strong delay fairness compared with MR/ED/PG+P and SR/ED/PG+D schemes according to a definition of delay fairness. However, other schemes are rather shown to have better delay fairness when the other definition is adopted.
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In this paper we propose a method fur the evaluation of the quality of service for VoIP services in NGN. Specifically, let us anatomize the elements of delay of a voice connection in the network in an end-to-end manner and investigate expected value at each point. We extract the delay time in each element in the network such as gateway, network node, and terminal equipment, and estimate an upper bound fur the tolerable delay in each element.
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This paper describes the design and implementation of PLC home network system using HNCP ver.1.0. The developed home network system comprises a home server progranL a home master, and appliance emulators (e.g., for washing machine, microwave oven, and air-conditioner). Throughout the implementation of PLC home network system, the feasibility of HNCP ver.1.0 is verified.
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In this paper, performance evaluation of HNCP home network is using stochastic activity network models is proposed. HNCP is a home network protocol for controling and monitoring home appliances using power line communication. a CSMA/CA with packet drop method is used in HNCP MAC layer. Using the proposed stochastic activity network models. performances of HNCP home networks with error-free environment and error environment are evaluated.
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최근 IEEE에서 WLAN을 표준으로 하는 802.11g가 확정되면서 이를 지원하는 AP가 출시되었다. AP에서 사용되는 OS는 POSIX를 기반으로 된 Linux 같은 OS를 통하여 구현되고 있 다. 이 논문에서는 가장 범용으로 사용되고 있는 Rad Hat을 기반으로 한 embeded linux를 만들어본다. 이와 함께 embeded linux를 가지고서 Network 기능을 추가하고, AP 하드웨어 드라이버 및 AP 모듈을 올려서 구연한다. 여기에 추가적으로 DHCP나 Web UI기능 등의 부가 기능을 추가하여 AP를 구현하는데 목적이 있다.
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In IEEE 802.11b, Medium Access Control Sublayer consists of DCF (Distributed Coordination Function) and PCF (Point Coordination Function). DCF provides contention based services and PCF provides contention free services for QoS satisfaction. DCF uses CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) as an access protocol. And PCF uses Polling Scheme. In this paper, a modified New-PCF, which gives weights to channels with heavier traffic load, was suggested. NS-2 simulations were conducted to compare the service performances with original DCF, PCF and the modified New-PCF respectively. Simulation results has shown the increased overall throughput with the proposed New-PCF compared with other cases.
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BEE 802.11 Wireless LAN protocol uses fixed transmission power. It does not consider a power control mechanism based on the distance between the transmitter and the receiver in order to improve overall channel utilization. In home environment, where stations generally lie around an AP, the AP is subject to use transmission power more than it needs. And wireless LAN stations may require different minimal desired received power. If there are many adjacent BSSs in densely populated WLAN area, they might cause RF interference to one another. In this paper we focus on the improvement of aggregate utilization by mitigating RF interference among BSSs. We show that RF interference by APs can be reduced by controlling transmission power using Link Margin information. The reduced interference will then lead to the increased aggregate throughput which is efficient resource utilization.
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By minimizing the burst error of data and correcting the error, we can define the convolution coding and interleaving in IEEE 802.11a wireless tan system. Two step block interleaver was decided by coded bits per OFDM symbol and due to this it comes to the delay time in IEEE 802.11a. This is the point of the question which we must consider. We try to decrease the delay time by all 48-clock from interleavings, and we have proposed a way carried out the interleaving outputs per symbol. So in comparison with the existing interleaver, we can decrease the delay time in reading and writing data, as well as reduce the delay time of bit re-ordering per symbol. Also this scheme is apply in all x-QAM cases.
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MIMO-OFDM 시스템은 다중 안테나 송신을 통하여 시스템의 capacity를 극대화하지만, 이를 위해서는 정확한 채널 계수 값의 추정을 필요로 한다. 본 논문에서 는 MIMO-OFDM 시스템을 위한 채널계수 추정기법으로서 Space-Time Coding(STC)에 기반을 둔 방식을 제안한다. 제안된 채널계수 추정기법을 위해 필요한 심볼구조, frame 구조를 IEEE 802.11a 시스템에 적용하였다. VBLAST 기법이 적용된 IEEE 802.11a 기반의 4 by 4 MIMO-OFDM 시스템에 대한 모의실험을 통하여 제안된 방법의 성능과 기존의 방법의 성능을 coded BER를 통해 비교 분석해 보았다.
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기존 IEEE 802.11 MAC (1)에서는 Fairness를 보장하며 Resource를 제공하는 것을 목표로 동일한 DIFS, Back-off 알고리즘, Source가 같은 경우 동일한 Frame size등을 사용하는 Specification을 작성하여 구현한다. 최근 Home Network과 같은 특수한 Ad-Hoc 환경에서의 이런 Fairness Resource Usage가 오히려 기대 성능을 떨어뜨리는 결과를 가져오고 있다. 이에 802.11 MAC에서 Backward Compatibility를 유지하면서 Prioritized DIFS/Backoff/Frame를 통해 차등화된 서비스를 제공하는 메커니즘을 제안하고자 하는 것이 본 논문의 목표이다.
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본 논문에서는 IEEE 802.11e MAC (Medium Access Control) 프로토콜을 NS-2 등과 같은 유명한 시뮬레이터들보다도 진보적인 NCTUns 시뮬레이터를 이용하여 개발하고자 하면서, 각 MSDU (MAC Service Data Unit)마다 제공되어야 하는 TID (Traffic Identification) 를 결정하는 방안을 모색하고 있다. 따라서 본론에서는 IEEE 802.l1e MAC 프로토콜과 NCTUns 시뮬레이터 에 대해서 기술하며 본 논문에서 제안하는 방법에 대해서 서술한다.
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In this paper, we present performance analysis of an IEEE P802.15.3a high rate wireless personal area network transceiver. This physical layer standard uses QOSK as its sub-channel modulation scheme and orthogonal frequency domain modulation (OFDM) for sub-bands. OFDM is used for each sub-band so that multi-path effects are absorbed by equalizer and guard, and fading can be approximately modeled as additive white Gaussian noise. In multi-band ultra-wideband system, DAC quantization error is important noise source since high resolution conversion cannot be used due to high power consumption. Simulation result shows that, to get 640-Mbps throughput, at least 5-bits precision is necessary to maintain bit-error rate under 10
$\^$ -2/, which can be lowered, with channel coding, to 10$\^$ -6/ that is the bit-error rate required by IEEE 802.15 upper protocol layer, in 4-meter LOS fading channel. -
In this paper, we propose new agent discovery and route discovery schemes to support Mobile IP (MIP) in Ad Hoc networks with wireless backbone. The wireless backbone consisting of stationary wireless routers and Internet gateways (IGs) is a kind of wireless access network of IP-based core network. The proposed scheme utilizes favorable features of wireless backbone such as stable links and no energy constraints. In the agent discovery scheme, backbone-limited periodic Agent Advertisement (AA) and proxy-AA messages are used, which reduce network-wide broadcasting overhead caused by AA and Agent Solicitation messages and decentralize MIP processing overhead in IGs. In order to reduce delay time and control message overhead during route discovery far the destination outside Ad Hoc network, we propose a cache-based scheme which can be easily added to the conventional on-demand routing protocols. The proposed schemes can reduce control overhead during agent discovery and route discovery, and efficiently support MIP in Ad Hoc network with wireless backbone.
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Mobile SCTP (mSCTP) is a new scheme which can be used to provide seamless handover for the mobile node. The reason that is possible is because of the SCTP extension which provides a method to reconfigure IP address on an existing SCTP association (ADDIP). While mSCTP focuses on an association originated ken mobile node (MN) toward fixed correspondent node (CN), mSCTP with Mobile IP support an association originated from CN toward MN by using the Home Agent in Mobile IP and location management. However, there are still some problems related to communication interruption. In this paper, we present a new scheme to solve these problems. The main idea of this scheme is using the home address of MN as a backup path of an SCTP association.
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In this paper, we propose the enhanced CSMA/CA MAC protocol fir mobile multi-hop wireless Ad-hoc networks. In the conventional wireless Ad-hoc network such as WLAN using CSMA/CA MAC protocol, communications between terminals that fn connected within multi-hop node may degrade the transmission efficiencies as increasing the multi-hop nodes because of RTS-CTS-DATA-ACK message exchange between terminals. In this raper, we apply the ACK/RTS control message into multi-hop transmission between terminals for wireless ad-hoc networks and improve the data traffic transmission efficiencies compared with conventional CSMA/CA MAC protocol used in WLAN.
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본 논문에선 Binomial확률을 이용한 재전송 슬롯 선택방식과 충돌해결과정의 수정을 통하여 CSMA/CA 프로토콜을 항공용 VHF통신에 적합하게 변형시켰다. 일반적으로 CSMA/CA 프로세스는 경쟁 서비스에서 충돌이 일어났을 때 재전송 지연시간만큼 기다리게 되고 경쟁윈도우의 크기가 두 배로 커진다. 이로 인해 부하가 증가하면 지연시간이 커지고 처리량이 감소하며 이를 해결하기 위해 본 논문에선 충돌 플래그를 이용하여 본래의 CW의 크기 변화 과정을 변형시켰으며, CSMA/CA 전체 상태 천이 과정에서 충돌 시의 과정을 좀더 적게 거치도록 하였다. 시뮬레이션을 수행한 결과 부하가 증가하여도 처리량 및 지연 시간에 좋은 특성을 나타내었으며 제안된 프로토콜은 항공용 VHF 통신에 적합함을 확인하였다.
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이 논문에서는 기존 연구 활동에 쓰이는 NS-2 시뮬레이터와 최근 대만의 National Chiao Tung University에서 개발하여 주목을 받고 있는 네트워크 시뮬레이터인 NCTUns에서 On-Demand 방식의 Ad Hoc 라우팅 프로토콜 중 AODV와 DSR의 성능을 분석하여 그 결과를 논하였다. NCTUns의 경우 작은 규모의 실험에서는 원할 한 성능을 보여주지만 노드수가 증가하면 불안정한 성능을 보여준다. 그러나 NS-2의 경우 NCTUns가 보여준 문제점 없이 원할 한 통신을 보여준다. 이에 앞으로의 실험에서는 Ad Hoc 관련 실험에서 보다 안정적인 성능을 보이고 있는 NS-2의 프로토콜 모듈을 NCTUns에 보강하면 보다 안정적인 시뮬레이터가 될 것으로 기대한다.
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There is no establishment of common plans fer the equitable use of frequency bands by terrestrial radiocommunications services in areas of far east countries including Korea. Main purpose of this paper is to propose the coordination procedure and related remarks between terrestrial wireless services in far east countries. In order to achieve this purpose, not only ITU-R regulations and recommendations on coordination but also agreements between some European countries and between northern American countries have been carefully reviewed and analyzed.
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Mobile wire technology is a publicly available general purpose for Radio Frequency(RF) communication for short-range and point-to-multi point voice and data transfer. In this paper, we proposed a new technology of the synchronized frame structure which is based on the CDMA technique, and it's implemented into the VLSI design by FPGA. The developmental technique consists of an assigned coded type mobile communication equipments and available local mobile or wireless communication scheme quasi BT(Blue Tooth)'s functions as multiplexer or do-multiplexer for each other applications. We implement this architecture with special proposed frame structure in the local area network. Also, we expect the above proposed structure extend into the DS3 network architecture and applicable to the TE(Terminal Equipment) in the local communication area and the other one etc.
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In this paper, we develop an effective method for estimating and predicting interference power strength using the IMM(Interacting Multiple Model) algorithm. Based on the proposed interference prediction algorithm, we adjust transmission power of mobile terminals to maintain a certain level of target signal - to - interference- plus -noise- ratio ( SINR ) at the base station. Results of numerical experiments are presented to show a performance profile of the proposed algorithm.
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To design the Bluetooth core efficiently, I analyzed the entire architecture and basic functions in the baseband and attempted to implement a Bluetooth one-chip solution on the basis of the Bluetooth SIG specification 1.1. We implemented important blocks into the hardware and firmware and found increased efficiency implementation when compared with the results of the implementation that using the criterion of size, Performance, stability, etc. And then to connect the baseband to the SE3208 core of the EISC type, we defined the baseband register and discovered a suitable method by comparing two results with the two connection ways.
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In this paper, we designed and implemented digital wireless audio system with embedded RTOS using Bluetooth. Transmitter is consisted of a Settopbox, FIFO for interface block, Microprocessor(ARM7TDMI), UART driver and Bluetooth module. Receiver is consisted of a Microprocessor, AC-3 decoder, Bluetooth module and a Speaker with Amp. We programed Bluetooth protocal stack of HCI, L2CAP, and RFCOMM, so that Bluetooth module interacts with CPU.
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In this paper, we propose new simple and efficient stopping criteria for W-CDMA turbo decoding. The new criteria are based on the sum of logarithm of absolute extrinsic information values and the count of one-estimations calculated after each component decoder. The calculation of the proposed criteria can be made simpler by summing one of ten values without any penalty. This Proposed method can be implemented with negligible overhead and no extra memory. Simulation results on W-CDMA standard shows that the number of iterations required is reduced compared to the existing stopping criteria without degrading the BER performance. Reduced iterations and simple operations make the proposed criteria desirable for low-power turbo decoder.
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Ad hoc 네트워크에 대한 상업적인 관심이 지속적으로 증가함에 따라, 최근 Ad hoc 네트워크에 QoS (Quality of Service)를 지원하기 위한 많은 연구가 이루어지고 있다. 지금까지의 연구는 대부분 QoS 기반 라우팅 프로토콜과 자원 예약 (resource reservation) 그리고 QoS MAC (Medium Access Control) 프로토콜에 관한 것이었다. Ad hoc 네트워크에 QoS를 제공하기 위해서는 위의 요소들이 상호 협력하여 동작하고 Ad hoc 네트워크의 특성이 충분히 고려된 005 모델에 관한 연구가 절실히 필요하다. 본 논문에서는 Ad hoc 네트워크에서 종단 사용자간 (end-to-end) 005를 제공하기 위한 서비스 모델의 설계와 구현방법에 대해 제안하였다.
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In this paper, we designed and made up/down converter (UDC) for using W-CDMA digital pre-distortion system which is one of the efficiency enhancement techniques. UDC is required that frequency up(baseband to RF) and down(RF to baseband) of information signals. The focus of the design and PCB layout is to satisfy the linearity of the UDC. We tested that UDC was satisfied specification which is based on 3GPP base stations and repeaters. The ACLR results which are -51.84dBc(Up Converter) and -55.0dBc(Down Converter) at upper 5 MHz offset from center-frequency show that UDC satisfy the 3GPP specification with superior linearity data.
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In this paper, we analyze the performance of transmitter and receiver of W-CDMA system using the channel coding and space time code in downlink over ITU-R realistic channel model. We can improve the reliability of communications and increase the data rate by channel coding, and we can get a diversity gain by using the space time code over fading channels. We also apply the RAKE receiver to improve tile performance in multi-Path fading channel environment.
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Multi-code CDMA is an appropriate scheme for transmitting high rate data. However, dynamic range of the signal is large, and power amplifier with good linearity is required. Code select CDMA (CS/CDMA) is a variation of multi-code CDMA scheme that ensures constant amplitude transmission. In CS/CDMA input data selects multiple orthogonal codes, and sum of these selected codes are MPSK modulated to convert multi-level symbol into different carrier phases. CS/CDMA system employs level clipping to limit the number of levels at the output symbol to avoid hish density of signal constellation. In our previous work we showed that by encoding input data of CS/CDMA amplitude of the output symbol can be made constant. With this coding scheme, level clipping is not necessary and the output signal can be BPSK modulated for transmission. In this paper we show that the constant amplitude coded(CA-) CS/CDMA transmitter can be implemented using only logic gates, and the hardware complexity is very low. In the proposed transmitter architecture there is no apparent redundant encoder block which plays a major role in the constant amplitude coded CS/CDMA.
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Code Select CDMA(CS/CDMA)(1)는 입력 데이터 열에 의하여 여러 채널의 직교코드를 선택하여 전송하는 기술로, 멀티코드 CDMA 의 구조를 가지면서도 전송신호의 크기가 일정하여 저가의 비선형 증폭기를 사용하여 구현 할 수 있다. 특히 입력 비트열을 부호화하여 직교코드들의 합을 일정하게 만드는 constant amplitude coded (CA-) CS/CDMA (2) 전송 기술은 2.4GHz ISM 대역의 WPAN을 위한 전송방식의 하나로 고려되고 있다. 이주파수 대역은 WLAN, 블루투스 등을 비롯한 여러 시스템이 존재하는 대역이므로 다른 종류의 시스템과의 상호 간섭의 문제를 분석할 필요가 있다. 본 논문에서는 2.4GHz ISM 대역을 같이 사용하게 될 IEEE 802.11b WLAN 과 CA-CS/CDMA 기반의 WPAN 상호 영향을 물리계층 측면에서 분석한다. IEEE 802.11b 모델로 11MHz 대역폭을 갖는 CCK (Complementary Code Keying) 변조방식을 대상으로 하며, CA-CS/CDMA 와의 중심주파수 차이에 따른 비트오율 성능을 신호대 간섭전력의 비를 변화시켜가면서 컴퓨터 모의실험을 통하여 분석하였다.
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이 논문은 WCDMA 와 안테나 배열 시스템에서 저 레벨 양자화와 MUSIC 알고리즘을 사용하여 신호의 방향을 추정하는 방법을 제안한다. 추가의 Power-Up Function 이 필요 없는 방향각 방법으로 이동가입자의 위치를 알아내기 위해 안테나 배열을 이용하여, WCDMA 시스템에서 역확산 코드로 다수의 신호를 분리하고, 각 신호를 저 레벨로 양자화 시켜 MUSIC 으로 신호의 방향각을 추정하였다. 이 방법을 이용하면 단말기의 안테나 출력파워가 낮더라도 기존 방법의 에러율과 비슷함을 시뮬레이션 결과로 알 수 있고, 양자화 비트를 처리하기 위해 필요한 메모리 또한 줄일 수 있어 하드웨어의 비용을 줄일 수 있을 것이다.
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This paper evaluates the RF transmitting parameters of User Equipment(UE) for W-CDMA system based on 3GPP specifications. The parameters of transmitter are derived from the aspect of RF. In order to keep UE in high performance, the transmitter requirements such as ACLR, EVM, Peak Code Domain Error, spectrum emission mask are considered. The UE transceiver is implemented on the basis of performance requirements and then tested for the analysis of RF transmitter characteristics through test scenarios.
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The binary clipping PW/CDMA system is considered. This system can be constructed with effective cost. leading to reduce the influence of the non-linear amplifier because of converting multi-level signals into constant envelope signals. In addition, the clipping method which is to clip out signal amplitude at some level when multi-level signals are converted into constant envelope signals is used. The multi-level signals are clipped at 1 and -1 to limit the extension of bandwidth and to maintain the bandwidth after clipping. In this paper, the performance of the binary clipping PW/CDMA system with the non-linear amplifier analyzed by simulation over AWGN and flat fading channels respectively. The binary clipping PW/CDMA system with the non-linear amplifier is 2.2dB and 0.9dB better than conventional DS/CDMA system over the flat fading channels when the number of users are 9 and 17 respectively.
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3GPP RLC protocol specification adopted an error control scheme based on selective repeat ARQ. In the 3GPP ARQ, distinctive windows are provided at transmitting and receiving stations so that those stations are prohibited to send or receive data PDU's out of window. An increase in window size enhances delay performance. Such an increase, however, raises the occupancy at re-ordering buffer, which results in a long re-ordering time. Aiming at suppressing the occupancy at re-ordering buffer, we propose partial go back N scheme in this paper In the partial go back N scheme, the receiving station regards all data PDU's between the first (lowest sequence numbered) error-detected PDU and last (highest sequence numbered) error-detected PDU. By the employment of the partial go back N scheme, the occupancy at the re-ordering buffer is apparently reduced, while the delay and throughput performance may be degraded due to the remaining properties of go back N. We thus consider peak occupancy of re-ordering buffer, mean sojourn time at re-ordering buffer, mean delay time, and maximum throughput as measures to evaluate tile proposed scheme and investigate such performance by using a simulation method. From numerical examples, we observe a trade-off among performance measures and conclude that the partial go back N scheme is able to effectively reduce the occupancy of re-ordering buffer.
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In this study, the electrical characteristic of Symmetric high voltage MOSFET (SHVMOSFET) for display driver IC were investigated. Measurement data are taken over range of temperature (300K-400K) and various extended drain length. In high temperature condition(>400K), drain current decreased over 20%, and specific on-resistance increased over 30% in comparison with room temperature.
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The LTCC bandpass filter using multilayer resonators is made of combline type and interdigital type parallel coupled-lines. The equivalent circuits of parallel coupled-lines are analysed. They are applied to make an equivalent circuit of LTCC bandpass filter using multilayer resonators. The 3-pole bandpass filter of the center frequency of 2.45GHz with 200Hz bandwidth is designed and fabricated. The simulated result of the bandpass filter are presented.
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In this paper, we design a slow-wave bandpass filter that uses a microstrip line periodically loaded with microstrip ing resonators for WLAN(5 GHz). Unlike conventional slow-wave filters, this filter is designed to produce a narrow passband at the fundamental mode of the resonators and provide lower insertion loss than that of parallel- or cross-coupled ring bandpass filters. A PBG(Photonic Band Gap) structure patterned in the ground plane is used to suppress the spurious transmission and extend out-of-band rejections Experimental result shows that the first spurious response in the stopband of the slow-wave bandpass filter can be rejected using a PBG structure.
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본 논문은 무선 음성/영상 송수신용 RF모듈 설계 및 제작하였다. RF 주파수는 정보통신부에서 고시한 영상전송용 2410, 2430, 3450, 2470MHz 사용하였으며 IF 주파수는 479.5MHz를 사용하였다. 설계 및 제작된 RF 모듈은 FR-4 재질인 유전체 4.6, 두게 0.8mm, 양면구조의 기판을 사용하여 50mm x 40mm 크기로 제작되었다. 설계된 송신기 모듈은 +5V 단일전원으로 9±1dBm의 출력과 주파수허용편차 50×10/sup -6/이하, 스퓨리어스 발사강도 기본주파수의 평균전력보다 40dB이하의 성능을 만족하였다. 수신기 모듈은 +5V 단일 전원으로 -80dBm이하의 수신감도로 만족할만한 성능을 보였다.
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A novel compact circular polarization operation of the microstrip antenna with four-slits and T-slits is proposed. The mechanism for compact size antenna is investigated with the behavior of the currents on the radiating patch. The equivalent surface current path due to the slits is lengthened, reducing the resonant frequency at a fixed patch size. The proposed compact CP design can have an antenna size reduction of about 33 ∼ 45% as compared to the conventional microstrip antenna. Details of the experimental and measured results are presented and analysed.
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This letter presents the design and measured performance of bandpass filters based on a stacked-SIR (stepped impedance resonators) configuration with DGS (Defected Ground Structure). An unit DGS configuration is designed and analyzed to show the phase characteristic of proposed slow-wave structure. The SIR filter with DGS has been yielded better stop band and sharper skirt behavior than conventional bandpass filter.
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This Paper describes the design and the simulation results of the RF CMOS Class-E Power Amplifier for a 2.4GHz ISM band. This circuit is composed two connected amplifiers. where Class F amplifier drives Class E amplifier. The proposed circuit can reduce the total power dissipation of the driving stage and can work with higher efficiency. The power amplifier has been implemented in a standard 0.25
$\mu\textrm{m}$ CMOS technology and is shown to deliver 100mW output Power to load with 41% power added efficiency(PAE) from a 2.5V supply. -
멀티미디어 서비스는 트래픽 특성이 비대칭이기 때문에 하향링크의 무선 자원 관리의 중요성이 부각되고 있다. 여기서 제안되는 알고리즘은 기존의 전력 기반의 알고리즘을 조합한 하이브리드 형태의 알고리즘으로 현재 셀의 상황에 따라서 admission control의 형태가 바뀌는 방식이다. 본 논문에서는 하이브리드 형태의 알고리즘과 기존의 전력 기반의 알고리즘을 simulation을 통해서 비교 분석한다.
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Overlay multicast is proposed as an alternative approach for providing muticast services. A logical infrastructure is built to form an overlay network on top of the physical layer. In this paper, we propose an efficient overlay multicast in wireless ad hoc networks. The overlay multicast tree adapts to the changes in underlying networks. The multicast tree adjusted according to the local member information.
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Due to low bandwidth and high error rate, the wireless Link is more frequent disconnected than the wired link. Link failure in the method invocation often appears as a failed method invocation. Framework of RMI is adjusted with queuing of method call. RMI's performance can be enhanced without breaking compatibility with Java RMI specification.
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As the wireless mobile telecommunication system has been developed with astonishment, its offering service has also widely been expanded including various data service. Currently, the wireless mobile telecommunication network presents voice service that covers for the most part of the whole service areas. For this reason, the availability of the switching capacity in the mobile switching center(MSC) is manipulated by the required volume of voice service. However, considering the increase of data service, it is desirable for the current switching method to be modified for more efficiency. In this Paper, we analyze the data traffic caused by providing data service in the wireless mobile telecommunication network. For this, we are firstly going to review the result of the analysis in the feature of the data traffic. Secondly, based on the review, we are also going to perform analyzing the other feature of the data traffic normally generated in the wireless mobile telecommunication network. We expect that this paper would be utilized as an elementary source for the feature of the SMS data .traffic and it will be an honour for ourselves to work on it.
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In this paper, we investigated the characteristics of 4
${\times}$ 4 thermo-optic switch using two mode interference(TMI) coupler. We designed this matrix switch by using a configuration which combines a double Mach- Zehnder interferometer(MZI) switching unit. The average extinction ratio and average excess loss of the 4${\times}$ 4 thermo-optic switch was 33.7dB, 0.29dB, respectively. -
The customer premise facilities assume an important role in the telecommunication networks. The present technical standards for domestic customer cabling facilities are established with the multimedia environment reflected, but are insufficient for accommodation of multimedia services of the ultra high-speed information and communication networks In the present paper, the status of international standardization as well as technical standards in the U.S.A., Japan, other countries are reviewed and the domestic technical standard and emblem is investigated and analyzed in order to enhance customer cabling facilities in Korea. The problems with emblem are analyzed, and how to improve customer cabling telecommunication facilities is suggested based on the above.
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In this Paper, we report a design of Serial ATA Transpor layer. The functionalities of the Serial ATA transport layer are first described on RTL via verilog. The compiled code are then fed to a synthesizer synopsys to get the actual hardware from 0.35
$\mu\textrm{m}$ SAMSUNG standard cell library. The designed functionalities of this chip will be verified using test bold with FPGA equipment and ATS2 digital test equipment. -
홈오토메이션 시스템은 보통 데이터 양이 많지 않아 저속 전력선 통신을 사용하는데, 저속 전력선 통신은 대역 확산 방식과 위상 변조 방식이 사용된다. 이 통신 방식은 신호의 정보가 진폭에 없고, 위상 변화에 있으므로 본 논문에서는 신호가 두 개의 상태로 되는 D급 증폭 회로를 사용하여 저임피던스를 가진 전력선 채널에서 적합한 통신이 되도록 하였다. 현재 전력선 모뎀에 사용되는 전압 구동 회로와 전류 구동 회로를 제작하고, 본 논문에서 설계한 D급 증폭 회로를 이용한 구동 회로와 비교 실험을 하였다. 실험 결과 본 논문에서 설계한 구동 회로가 다른 구동 회로보다 낮은 전력선 채널 임피던스에 대하여 전달 특성이 우수함을 보였다.
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ISS UDIS (International Sapce Station Universal Data Interface simulator) is a data communication interface simulator between ISS and instrument. This paper explains design concept, and verifies operations of ISS UDIS simulator. By realization of the simulator, we ensure data interface skills for a manned-space data communication system.
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The Channel Coding Unit (CCU) is an integral component of Payload Data Transmission System (PDTS) for the Multi-Spectral Camera (MSC) data. The main function of the CCU is channel coding and encryption. CCU has two channels (I & Q) for data processing. The input of CCU is the output of DCSU (Data Compression & Storage Unit). The output of CCU is the input of QTX which modulate data for RF communication. In this paper, there are the overview, short H/W description and operation concept of CCU.
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Introduction of digital broadcasting service does not only mean the change of information transmission method but also the change of total broadcasting system. In past day, Television was only received one-sided information from broadcasting station, but digital broadcasting means that digital television becomes the most important means of information transmission by the introduction of new programming, lots of channels, data service, multi communication. In the age of the digital broadcasting, the recording and replay medium's interest is getting higher. The medium is able to record more than 24 hours' digital broadcasting programs without additional tapes. In this paper the recording and replay device using HDD was implemented and device driver based on linux was programmed. It has Intel PXA250 processor and hard disk is used as storage equipment. And transport Stream is saved on hard disk through PXA250's data bus. FIFO is added to solve the different saving speed and FPGA is also added to display the saved data.
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There is still lack of a convenient system that connect referring physicians to the information system of referral hospitals. In this paper, We proposed to implemented Referral system based on HL7 for exchange and sharing of clinical information. The Present implementation is based on HL7 v.2.4 using XML.
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In this work, we have designed Gilbert cell downconversion mixer using 0.25um Anam CMOS process, we also have analyzed Conversion gain and IIP3 using Taylor series in our own unique way. Especially, bulk terminal is used as LO( Local Oscillator) input for reduction of power consumption and supply voltage. Supply voltage used in this design is lower than 1.8V and core current is less than 500uA. The simulation experiments showed that the conversion gain, IIP3, and power consumption were -1 dB, 4.46dBm, and 0.8mW, respectively.
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본 논문에서는 multi-media service를 제공하는데 smart antenna system을 적용했을 때의 performance 를 각 서비스별 특성에 따라 평가한다. 서로 다른 다중 rate 의 신호가 각각의 안테나를 통해서 수신되는 환경 하에서 adaptive smart antenna를 적용함으로써 보다 고속이고 향상된 용량의 서비스를 제공할 수 있도록 하기 위해서는 사용자의 지리적 분포 또는 간섭 전력에 따라서 성능 특성이 달라지므로 이에 대한 성능 분석을 시뮬레이션을 통해서 수행한다.