• Title/Summary/Keyword: Precoder

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Limited Feedback and Scheduling for Coordinated SDMA (협력 공간 분할 다중 접속 기술을 위한 제한된 피드백과 스케줄링)

  • Mun, Cheol;Jung, Chang-Kyoo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.6
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    • pp.648-653
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    • 2011
  • In this paper, coordinated space division multiple access(SDMA) technology is proposed to mitigate inter-cell interference by using partial channel state information in cooperative wireless communications system with limited feedback. Each AT selects an optimal cluster transmission mode and sends it back to a cluster scheduler, and at the cluster scheduler, ATs are scheduled within a AT group with the identical cluster transmission mode, and the optimal transmission mode and the corresponding scheduled ATs are determined to maximize scheduling priority. Also, in order to enhance multiuser diversity gain, an extended transmission feedback method is proposed to feed back multiple preferred cluster transmission modes at each AT. It is shown that the proposed coordinated SDMA scheme outperforms existing non-coordinated SDMA schemes in terms of the average system throughput.

Performance Of Iterative Decoding Schemes As Various Channel Bit-Densities On The Perpendicular Magnetic Recording Channel (수직자기기록 채널에서 기록 밀도에 따른 반복복호 기법의 성능)

  • Park, Dong-Hyuk;Lee, Jae-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.7C
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    • pp.611-617
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    • 2010
  • In this paper, we investigate the performances of the serial concatenated convolutional codes (SCCC) and low-density parity-check (LDPC) codes on perpendicular magnetic recording (PMR) channels. We discuss the performance of two systems when user bit-densities are 1.7, 2.0, 2.4 and 2.8, respectively. The SCCC system is less complex than LDPC system. The SCCC system consists of recursive systematic convolutional (RSC) codes encoder/decoder, precoder and random interleaver. The decoding algorithm of the SCCC system is the soft message-passing algorithm and the decoding algorithm of the LDPC system is the log domain sum-product algorithm (SPA). When we apply the iterative decoding between channel detector and the error control codes (ECC) decoder, the SCCC system is compatible with the LDPC system even at the high user bit density.