• Journal of Broadcast Engineering
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• v.9 no.1
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• pp.32-42
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• 2004

In this paper we apply space-time block code with multiple transmitter/receiver antennas to the Advanced Television Systems Committee (ATSC) terrestrial broadcasting systems. Especially, we apply Aiamouti scheme with two transmitter antennas and multiple receiver antennas to the ATSC broadcasting system. Also. diversity technique with multiple receiver antennas and space-time block code scheme with multiple transmitter/receiver antennas are compared. Our simulation results show that the ATSC broadcasting system with multiple transmitter/receiver antennas has an extremely good performance than the scheme with single transmitter/receiver antenna in the Rayleigh fading channel.

• Journal of Communications and Networks
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• v.12 no.4
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• pp.308-316
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• 2010

The problem of compressed sensing (CS) based multiple access is studied under the assumption of random data traffic. In many multiple access systems, i.e., wireless sensor networks (WSNs), data arrival is random due to the bursty data traffic for every transmitter. Following the recently developed CS methodology, the technique of compressing the transmitter identities into data transmissions is proposed, such that it is unnecessary for a transmitter to inform the base station its identity and its request to transmit. The proposed compressed multiple access scheme identifies transmitters and recovers data symbols jointly. Numerical simulations demonstrate that, compared with traditional multiple access approaches like carrier sense multiple access (CSMA), the proposed CS based scheme achieves better expectation and variance of packet delays when the traffic load is not too small.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1112-1115
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• 1990

Described is a new control signal transmission system which utilizes an optical fiber to transmit 2-bit control signals from the transmitter to receiver. In the transmitter the DC series control voltages are converted into the multiple frequency signals by voltage controlled oscillator (VCO). The multiple frequency signals can easily be transmitted by optical fiber. In the receiver the multiple frequency signals can be detected by analog or digital circuits and then be converted into 2-state control signals which can be used for a variety of applications.

• Journal of information and communication convergence engineering
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• v.6 no.4
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• pp.359-363
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• 2008

In this paper, the capacity of MIMO fading channel in the OFDM-based spatial multiplexing systems is analyzed when there is scattering at both transmitter and receiver. The employed MIMO channel model is spanning from the correlated low-rank case to uncorrelated high-rank case at both transmitter and receiver. The effects of spatial fading correlation on the capacity of MIMO channel is examined when the channel is known and unknown at the transmitter. We also evaluate the impacts of a channel estimation error at the transmitter on the MIMO channel capacity.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.6
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• pp.379-392
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• 2016

This paper presents the design and simulation of a laser power beaming (LPB) system for an electric vehicle that establishes an optimal power transmission path based on the received signal strength. The LPB system is possible to transfer power from multiple transmitters to a single receiver according to the characteristics of the laser and the solar panel. When the laser beams of multiple transmitters aim at a solar panel at the same time, the received power is the sum of all energy at a solar panel. Our proposed LPB system consists of multiple transmitters and multiple receivers. The transmitter sends its power characteristics as optically coded pulses with a class 1 laser beam and powers as a high-intensity laser beam. By using the attenuated power level, the receiver can estimate the maximum receivable powers from the transmitters and select optimal transmitters. Throughout the simulation, we verified the possibility that different LPB receivers were achieved their required power by the optimal allocation of the transmitter among the various transmitters.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.1184-1201
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• 1995

Two multiple access protocols are proposed for a multichannel WDM optical fibre local area network or metropolitan area network in which users are interconnected using a passive star topology. Each user has a single tunable transmitter and a single tunable receiver. A transmitter sends a control packet before its data packet transmission so that its intended receivers can tune to the proper data channel wavelength. The maximum throughput of the proposed protocols are independent of the effective normalized propagation delay which may include the transmitter and receiver tuning times and the processing delays. The maximum throughputs of the protocols are analyzed and compared with those of the existing ones by numerical examples. The message delay of the R- Aloha/synchronous N-server switch protocol which is suitable for the queued users is also analyzed.

• Journal of Communications and Networks
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• v.5 no.2
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• pp.116-123
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• 2003

In this paper, we address the problem of designing multirate codes for a multiple-input and multiple-output (MIMO) system by restricting the receiver to be a successive decoding and interference cancellation type, when each of the antennas is encoded independently. Furthermore, it is assumed that the receiver knows the instantaneous fading channel states but the transmitter does not have access to them. It is well known that, in theory, minimummean- square error (MMSE) based successive decoding of multiple access (in multi-user communications) and MIMO channels achieves the total channel capacity. However, for this scheme to perform optimally, the optimal rates of each antenna (per-antenna rates) must be known at the transmitter. We show that the optimal per-antenna rates at the transmitter can be estimated using only the statistical characteristics of the MIMO channel in time-varying Rayleigh MIMO channel environments. Based on the results, multirate codes are designed using punctured turbo codes for a horizontal codedMIMOsystem. Simulation results show performances within about one to two dBs of MIMO channel capacity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.7
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• pp.641-655
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• 1992

In this paper, the performance of the various multiple accesstechniques for the mobile computer network has been studied in the consideration of the characteristics. Of the mobile communication channel. In the case of the hidden node occurring, it could be seen that the performance of the code division multiple access(CDMA) technique. With simultaneous access function is better than that of the other packet access methods such as carrier sensed multiple access(CAMA). Busy tone mulitiple access(BTMA)and idle signal muitiple access(ISMA) in the view of the throuhtput and mean delay time. Also it has been shown that the performance of the CDMA method is superior to that of other packet access techniques such as multiple access(CSMA).etc when the fading effect or impulsive noise exists in the mobile channel. Especially in the case of the distributed mobile network. It has been shown that the receiver-transmitter based CDMA method using the characteristics of CDMA effectively has better throughput and less mean delay time than the commontransmitter based CDMA technique.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.10
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• pp.896-900
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• 2013

In this paper, we develop a dust detection sensor system capable of identifying types of dust for an improvement of a robot vacuum cleaner. The dust detection sensor system is composed of a set of infra-red sensors: a single transmitter and multiple receivers. Given the fixed amount of light transmitted from the transmitter, the amount of light coming in multiple receiver sensors varies, depending on the type and density of dust that is passing between the transmitter and the receivers. Therefore, the type of dust can be identified by means of observing the change of the amount of light from the receiver sensors. For experiments, we use two types of dust, rice and sesame, and validate the effectiveness of the proposed method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.1156-1173
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• 2021

In this paper, we propose a new joint precoder and postcoder design strategy to support multiple streams per user in multiuser multiple-input multiple-output (MIMO) systems. We propose two step precoding strategies using equal channel gain decomposition and block diagonalization at the transmitter. With the proposed precoder, the multiuser MIMO channel can be decomposed into multiple parallel channels with equal channel gain per user. After applying receive postcoder which is generated and sent by the transmitter, we can use ML based decoder per stream to achieve full receive diversity. Achievable sum rate bound and diversity performance of the proposed algorithm are presented with feedback signaling design and quantitative complexity analysis. Simulation results show that the proposed algorithm asymptotically approaches to the sum rate capacity of the MIMO broadcast channel while maintaining full diversity order.