• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.2059-2062
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• 2002

For detection of digitally modulated signals, the receiver must be provide with accurate carrier phase and symbol timing estimates. So far, tots of algorithms have been suggested for those purposes. In general, a interpolation filter with TED(Timing Error Detection) like Gardner algorithm is popularly used for symbol timing estimate of digital communication receiver. Apart from the performance point of view, a multiplicative operation of any interpolation filter limits the symbol rate of the system. Hence, we suggest a new symbol timing estimate algorithm for high speed burst-mode fixed wireless communication system and analyze its performance in the AWGN channel.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.319-325
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• 2015

We proposed the blocking channel to reduce the performance decrease using the low correlation with cyclic delay scheme in LED-ID system. LED-ID is based on the visible light to transmit the data. However, It is occurred the block channel by structure or environment of indoor for light of straightness. LED-ID system is degraded the performance by the block channel as loss of data, and burst error. To solve the block channel, the proposed system is overcome the burst error by low correlation among data, which is able to obtain the maximize time diversity gain to improve the performance of BER by cyclic delay scheme. The BER performance is evaluated by computer simulation according to channel parameter. The simulation results shows that proposed system gives much better performance than conventional system and constant cyclic delay scheme system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.167-174
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• 2012

The circuits including with Optical transceiver and clock data recovery, in this paper, SERDES (SERializer-DESerializer) are implemented to construct a GE-PON burst-mode transceiver supporting IEEE 802.3ah and a jig for measuring the burst-mode characteristics, that is to say, PON upstream optical transmission environment are manufactured to evaluate the performance of transceiver. we verified that the limiting amplifier compensated the gap of max. 26dB optical power by experiments. The startup acquisition lock time is 670ns in case of using VSC7123 and 2300ns in case of S2060 and the data acquisition lock time were measured to be 400ns and 600ns, respectively, in the upstream channel transmission in this work. While on the other, VSC7123 is satisfied with IEEE802.3ah recommendations.

• Journal of KIISE:Information Networking
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• v.37 no.3
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• pp.217-227
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• 2010

To apply active RFID technology in the various kinds of industry, it needs to quickly transmit a large amount of data. ISO/IEC 18000-7 standard uses the 433.92MHz as single channel system and its transmit rate is just 27.8kbps, that is insufficient for a large amount of data transmission. To solve this problem, we designed a new data transmission protocol using 2.4GHz band. The feature of designed protocol is not only making over 255bytes data messages using the Burst Read UDB but also efficiently transmitting it. To implement this protocol, we use Texas Instruments's SmartRF04 develop kit and CC2500 transceiver as RF module. As an evaluation of 63.75kbytes data transmission, we demonstrate that transmission time of Burst Read UDB has improved as 17.95% faster than that of Read UDB in the ISO/IEC 18000-7.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8B
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• pp.514-524
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• 2005

In optical burst switching(OBS) networks, the ingress edge router assembles packets in the same class queue into the appropriate size of burst. A burst control packet(BCP) is generated for channel reservation of corresponding data burst and sent earlier than the corresponding data burst with an offset time. Offset time is determined considering the number of hops from source to destination and the required quality of service(QoS). After offset time, the burst data is passed through tile pre-configured optical switches without any O/E/O conversion. But a failure in OBS networks may lead to the loss of bursts until the ingress nodes receive the failure indication signal. This results in a significant degradation in QoS. Therefore, in this paper, we propose a fault-tolerant node architecture based on sub-carrier multiplexing to reduce the effects of failure in OBS networks. The Performance of the proposed fault-tolerant node architecture exhibits considerable improvement as compared with the previous ones.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.7
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• pp.1477-1486
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• 1997

Conventioally the decoding methods and the design of coset codes for burst synchronization and error detection have been based on the concept that slips occuring to the right or to the left with respect to a reference timing are corrected. In this paper we newly approach to the design of coset codes relying on the condition that only a single code word can exists in an observation interval, which provides an extentended view on the conventional approach. A theorem concerning the condition is presented. A combined burst synchronization and error detection system with maximum slip correction capability have been devised based on the theorem and a detection method is falsely accepted in the presented of channel errors. The false acceptance probabilities of the system are derived and its performance is analyzed through computer computation using the derived results.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.72-73
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• 2003

In volume holographic memory (VHM), two-dimensional data array (i.e. data page) is used for the recording and the retrieving process with the aid of spatial light modulator (SLM) and CCD camera. Due to this two-dimensional parallel data processing, burst errors in this system also have two-dimensional characteristics in a data page domain. In this paper, we present a channel model of the burst noise and burst error for the VHM system using disk type recording media. (omitted)

• The Journal of the Acoustical Society of Korea
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• v.38 no.2
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• pp.207-213
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• 2019

In this paper, we evaluate the communication performance of convolutional code with block interleaving in a frequency-selective channel. Block interleaving is a technique for spreading and rearranging digital data streams. A block interleaving technique is applied to improve the performance by dispersing the concentration of burst errors in a frequency-selective channel. As a result of evaluating the performance of the convolutional code with block interleaving in the water tank experiment, There was no difference in the performance of convolutional codes using block interleaving in a frequency-selective channel. However, in the frequency-selective channel, the convolutional code with block interleaving has a gain of 2dB, and it is confirmed that the underwater acoustic communication performance is improved.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.1-17
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• 2016

The separated management and operation of commercial IP/optical multilayer networks makes network operators look for a unified control plane (UCP) to reduce their capital and operational expenditure. Software-defined networking (SDN) provides a central control plane with a programmable mechanism, regarded as a promising UCP for future optical networks. The general control and scheduling mechanism in SDN-based optical burst switching (OBS) networks is insufficient so the controller has to process a large number of messages per second, resulting in low network resource utilization. In view of this, this paper presents the burst-flow scheduling mechanism (BFSM) with a proposed scheduling algorithm considering channel usage. The simulation results show that, compared with the general control and scheduling mechanism, BFSM provides higher resource utilization and controller performance for the SDN-based OBS network in terms of burst loss rate, the number of messages to which the controller responds, and the average latency of the controller to process a message.

• Journal of Satellite, Information and Communications
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• v.4 no.2
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• pp.34-38
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• 2009

This paper is related with optimum burst structure design for high efficient TDMA satellite return link transmission. In general, some typical burst structure for data transmission is composed of a pair of preamble and traffic data in the DVB-RCS (Digital Video Broadcasting. Return Channel via Satellite) and IPOS (IP over Satellite) standard. This structure has some difficulties to increase spectral efficiency that it requires a large of preamble length, high SNR environment, or receiver complexity. To cope with them, burst structure with distributed pilot symbol can be used to alleviate the residual frequency offset effect by calculating accurate frequency offset than conventional one. In particular, we investigate some relevant to proposed distributed pilot structure, previously and analyze their strong points/drawbacks in terms of synchronization to draw the most appropriate one.