• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.334-342
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• 2017

Due to the development of telecommunication technology, the relay broadcasting system is changing rapidly. The introduction of the wireless mobile communication relay (DMNG) method has enabled the one-man relay, which has resulted in absolute reductions in terms of equipment and manpower. However, it is a reality that the basic level of broadcasting such as broadcasting stability and image quality is becoming less complete. This paper analyzes wireless telecommunication relay equipment and broadcasting system called 'backpack', and discusses future development plan. To do this, we analyze the success and failure cases of backpack relay broadcasting and present concrete plans.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.14-23
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• 2023

The cooperative communication systems using MIMO(multiple input multiple-output) relay are known as one of the most promising techniques to improve the performance and coverage of wireless communication systems. In this paper, we propose the cooperative communication systems using the relay with multi-antennas and DSTC(distributed space time coding) for decode-and-forward protocol. As using DSTC for DF(decode-and-forward), we can minimize the risk of error propagation at the wireless system using relay system. Also, the MIMO channel cab be formed by multi-antenna and DSTC at the MS(mobile station)-RS(relay station) and at the RS-BS(base station).Therefore, obtaining truly constructive the MIMO diversity and cooperative diversity gain from the proposed approach, the performance of system can be more improved than one of conventional system (relay with single antenna, no relay). The improvement in bit error rate is investigated through numerical analysis of the cooperative communication system with the proposed approach.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.219-226
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• 2005

With the rise of interest in sports and introduction of a five-day duty service, it is. increasing the desire for leisure and well-being recently. In this paper, 1 design and implement a baseball broadcasting system for PDAs to offer a sports broadcasting service using wireless network. The implemented baseball broadcasting system is composed of PDA clients, a relay reporter, and a relay server. Users can search and retrieve baseball-related information as well as relay broadcasting information using PDA.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.658-666
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• 2003

In this paper, we analyzed standard and characteristic of portable microwave digital FPU(Field Pick Up) transmission system in AWGN channel environment as basis step of research about share way of M/W broadcasting relay frequency. And we analyzed system performance through simulator design. Domestic case, digitize progress about broadcasting relay is propeled. Therefore, we wish to utilize to basis data about interference evaluation and domestic broadcasting relay standardization for reassignment of M/W band broadcasting relay frequency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11A
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• pp.853-860
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• 2011

In this paper, we proposed a transmission scheme for a full-duplex relay system that minimizes outage probability. A relay system with the full-duplex relay can mitigate resource inefficiency of a half-duplex relay system. However, the mobile station suffers from the interference because the base station and the relay station transmits signal simultaneously to the mobile station. First, we suggest a layered broadcasting for full-duplex relaying. Second, we derive an optimal power allocation for the layered broadcasting in terms of the outage probability minimization. The proposed algorithm shows better performance than a half-duplex relaying system with and without the diversity, and a conventional full-duplex relaying system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.39-44
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• 2010

In this paper, we analyze the performance of the cooperative cognitive radio relay system which is adapted the recently highly focused cognitive radio system. The performance comparison is made between the system with and that without the opportunistic transmission relay. Especially the selection combining is considered at the destination for simple implementation. In this case, the effect of the channel state information (CSI) delay, which is caused essentially by the process during the CSI delivery, to the system performance is considered. It is noticed that the performance of the system with the opportunistic relay degrades up to 0.6 dB at a given condition compared to the system without the opportunistic relay. And it is shown that the system performance is more sensitive to the CSI delay compared to the frequency acquisition probability of the cognitive radio relay.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.15-21
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• 2011

Cooperative diversity system can be applied to an ad-hoc network for reduction of the power consumption, for expansion of the communication range, and for improving the system performance. In a selection relay cooperative diversity system which selects the maximal SNR(Signal-to-noise ratio) relay for transmitting the source information, the selected strong relay transmits continuously under slow fading channel, consequently it reduces the network lifetime. To overcome this defect, recently the uniform power relay selection has been studied to expand the network life time. We apply the uniform power relay selection to a DOT(Double opportunistic transmit) cooperative system that select the transmit relays, of which the SNR of the transmit relays exceed both of the source-relay and the relay-destination threshold. And the performance of the system is analytically derived. The performance comparisons are made among SC(Selection combining), MRC(Maximal ratio combining), and uniform power relay selection of the cooperative diversity system. We noticed that the performance of the uniform power relay selection is inferior to that of others. It is interpreted that the uniform transmit opportunity to the selected relays for extension of the network lifetime degrades the performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.31-36
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• 2012

In this paper, we proposed spectrum sensing using cooperative relay to solve problem of sensing performance degradation due to CPE (Customer-Premises equipments) which causes low SNR (signal-to-noise ratio) problem. In cooperative communication system, AF (amplify-and-forward) and DF (decoded-and-forward) is widely used for relay mechanism. Also, it is expected that cooperative relay scheme guarantees the high sensing performance by its diversity gain. Based on these backgrounds, in this paper, we apply to cooperative relay scheme to the CR (Cognitive Radio) system, and simulation results show comparison of the sensing performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.147-151
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• 2010

In this paper, we propose network-coding based two-way relay communication using adaptive modulation scheme for satisfying relay QoS(Quality of Service) according to channel environment between user and relay. Two-way relay communication is bidirectional cooperative communication that users exchange own signal with help of relay. Network-coding based two-way relay communication can achieve high throughput compared to conventional scheme through reducing time slots. we propose adaptive M-QAM modulation scheme in network-coding based two-way relay communication for satisfying QoS of relay. Simulation result shows that the proposed scheme satisfies goal QoS of system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.17-23
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• 2012

Recently, for spectral efficiency and power saving, an incremental best relay selection of a cooperative diversity scheme is proposed. However during the best relay selection process, there may exist a delay between channel estimation and actual data transmission. Consequently, this delay causes outdated channel state information (CSI). We analytically derive the effect of the outdated CSI to an incremental best relay selection diversity scheme. It is noted that the system performance deteriorates with decreasing the value of the correlation coefficient sensitively. When the correlation coefficient reduces from 1 to 0.9, the most performance degradation is denoted. However, the performance degradation is diminished with decreasing the correlation coefficient.