• Title/Summary/Keyword: Receiver Systems

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Design of ATSC Broadcasting Systems Using the Alamouti Scheme (Alamouti 구조를 이용한 ATSC 방송 시스템 설계)

  • 박성익;정태진;김승원;이수인
    • 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.

Receiver Techniques for Ultra-wide-band Multiuser Systems over Fading Multipath Channels

  • Zhou, Xiaobo;Wang, Xiaodong
    • Journal of Communications and Networks
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    • v.5 no.2
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    • pp.167-173
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    • 2003
  • We treat the problem of channel estimation and interference cancellation in multiuser ultra-wide-band (UWB) communication systems over multipath fading channels. The UWB system under consideration employs a random time-hopping impulse radio format. We develop a channel estimation method based on linear weighted algorithm. An iterative channel estimation and interference cancellation scheme is proposed to successively improve the receiver performance. We also consider systems employing multiple transmit and/or receive antennas. For systems with multiple receive antennas, we develop a diversity receiver for the wellseparated antennas. For systems with multiple transmit antennas, we propose to make use of Alamouti’s space-time transmission scheme, and develop the corresponding channel estimation and interference cancellation receiver techniques. Simulation results are provided to demonstrate the performance of various UWB receiver techniques developed in this paper.

A Simplified Zero-Forcing Receiver for Multi-User Uplink Systems Based on CB-OSFB Modulation

  • Bian, Xin;Tian, Jinfeng;Wang, Hong;Li, Mingqi;Song, Rongfang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.5
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    • pp.2275-2293
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    • 2020
  • This paper focuses on the simplified receiver design for multi-user circular block oversampled filter bank (CB-OSFB) uplink systems. Through application of discrete Fourier transform (DFT), the special banded structure and circular properties of the modulation matrix in the frequency domain of each user are derived. By exploiting the newly derived properties, a simplified zero-forcing (ZF) receiver is proposed for multi-user CB-OSFB uplink systems in the multipath channels. In the proposed receiver, the matrix inversion operation of the large dimension multi-user equivalent channel matrix is transformed into DFTs and smaller size matrix inversion operations. Simulation is given to show that the proposed ZF receiver can dramatically reduce the computational complexity while with almost the same symbol error rate as that of the traditional ZF receiver.

GA-based Adaptive Load Balancing Method in Distributed Systems

  • Lee, Seong-Hoon;Lee, Sang-Gu
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.2 no.1
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    • pp.59-64
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    • 2002
  • In the sender-initiated load balancing algorithms, the sender continues to send an unnecessary request message fur load transfer until a receiver is found while the system load is heavy. Meanwhile, in the receiver-initiated load balancing algorithms, the receiver continues to send an unnecessary request message for load acquisition until a sender is found while the system load is light. These unnecessary request messages result in inefficient communications, low CPU utilization, and low system throughput in distributed systems. To solve these problems, in this paper, we propose a genetic algorithm based approach fur improved sender-initiated and receiver-initiated load balancing. The proposed algorithm is used for new adaptive load balancing approach. Compared with the conventional sender-initiated and receiver-initiated load balancing algorithms, the proposed algorithm decreases the response time and increases the acceptance rate.

Performance of hybrid spead spectrum systems in rayleigh fading channel (레일레이 페이딩 채널에서 하이브리드 확산대역 시스팀의 성능)

  • 조현욱;박상규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.8
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    • pp.2023-2032
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    • 1996
  • In this paper, we calculate average bit error probabilities of asynchronous hybrid DS/FH-SSMA systems in AWGN chnnel and nonselective Rayleigh fading channel. We analyze and compare the performance of systems in AWGN channel and Rayleigh fading channel by using linear correlation receiver and hard limiting correlation receiver(nonlinear correlation receiver). Binary PSK scheme is considered and random spreading code sequences and random hopping patterns are used. Bit error probabilities of the systems with/without near-far problem under the same bandwidth expansion are calculated. the result shows that the performance of hard limiting correlation receiver is better than that of linear correlation receiver over nonselective Rayleigh fading channel.

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Design of Effective Receiver in Wideband-CDMA Systems Using Turbo Code

  • Cho, Seong-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.10
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    • pp.158-163
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    • 2006
  • In this paper, we considered the received signal of the wideband CDMA systems using turbo code in the multipath channel environments, and analyze the performance of the system. This study is to analyze the performance for the variable system bandwidth according to the number of branches of rake receiver by passing the received signal through a rake receiver with a turbo code in Rayleigh fading channel environments. For the design of receiver in wideband CDMA systems, we presented the efficient parameters for the number of iterative decoding and the number of branches of rake receiver.

Receiver Protection from Electrical Shock in Vehicle Wireless Charging Environments

  • Park, Taejun;Hwang, Kwang-il
    • Journal of Information Processing Systems
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    • v.16 no.3
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    • pp.677-687
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    • 2020
  • This paper deals with the electrical shock that can occur in a car wireless charging system. The recently released the Wireless Power Consortium (WPC) standard specifies that the receiver must be protected from the radio power generated by the transmitter and presents two scenarios in which the receiver may be subjected to electrical shock due to the wireless power generated by the transmitter. The WPC also provides a hardware approach for blocking the wireless power generated by the transmitter to protect the receiver in each situation. In addition, it presents the hardware constraints that must be applied to the transmitter and the parameters that must be constrained by the software. In this paper, we analyze the results of the electric shock in the vehicle using the WPC certified transmitter and receiver in the scenarios presented by WPC. As a result, we found that all the scenarios had electrical shocks on the receiver, which could have a significant impact on the receiver circuitry. Therefore, we propose wireless power transfer limit (WPTL) algorithm to protect receiver circuitry in various vehicle charging environments.

A Study on Code Channels Division for Multi-code CDMA (다중코드 CDMA를 위한 코드채널 분리에 관한 연구)

  • 김종엽;이선근;김환용
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.134-137
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    • 1999
  • The MC-CDMA(Multi-Code CDMA) systems for handling various data transmission rate which is demanded in the IMT-2000 systems are effective transmission technology, which can provide the higher data service than the conventional IS-95 CDMA systems because a user takes advantage of a number of channels. The receiver of MC-CDMA systems to be provided these data service have to be structured of demodulating simultaneously a number of traffic channels. This paper is designed the merged rake receiver demodulating simultaneously a number of traffic channels in the MC-CDMA systems. The merged rake receiver is to reduce the complexity of receiver resulting a number of channels.

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Multistage Parallel Nulling-Partial PIC Receiver for Downlink MIMO MC-CDMA Systems (하향링크 다중 안테나 MC-CDMA 시스템을 위한 다단계 병렬 널링 및 병렬 부분 간섭 제거 수신기 설계)

  • 구정회;김경연;심세준;이충용
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.11
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    • pp.1-7
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    • 2004
  • We propose multistage parallel nulling (MPN) partial parallel interference cancellation (PPIC) receiver for downlink multiple-input multiple-output (MIMO) multicarrier (MC)-code division multiple access (CDMA) systems. Though the V-BLAST is a popular MIMO receiver, it shows error floor for multiuser downlink MIMO MC-CDMA systems. The proposed MPN-PPIC receiver does not produce error floor for multiuser case, and achieves substantial performance gains with multistage processing. For single user case, the proposed method also surpasses the V-BLAST receiver with multistage processing for MIMO MC-CDMA systems with chip level interleaving. The system performance of the proposed MPN-PPIC receiver is evaluated through computer simulations.

A Study on Direct Decision Blind Adaptive Interference Suppression for DS-CDMA Systems (DS-CDMA 시스템을 위한 직접 결정 블라인드 적응 간섭 억제에 관한 연구)

  • 우대호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.10B
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    • pp.1714-1721
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    • 2000
  • In the mobile communication using DS-CDMA systems the problem of multiple user interference which reduce the performance is generated by multiple user access. In this paper to solve this problem we proposed the direct decision blind adaptive receiver with knowledge of only the desired user's spreading sequence. Simulation result present that the total user's power has equal gain The gain of signal to interference ratio for the proposed blind DD-LMS receiver has about 6[dB] than conventional receiver at additive white Gaussian noise and large gain at multipath channels. And when interference user's power has more large gain than desired user's power the gain of SIR for the proposed receiver has large value. And simulation result of bit error rate present that DD-LMS receiver has higher performance than LCCMA receiver. Thus the proposed blind DD-LMS receiver has robustness against interference of high power user and multipath channels.

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