The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Code Rate 1/2, 2304-b LDPC Decoder for IEEE 802.16e WiMAX

IEEE 802.16e WiMAX용 부호율 1/2, 2304-비트 LDPC 복호기

  • Received : 2010.12.08
  • Accepted : 2011.03.31
  • Published : 2011.04.30
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Abstract

This paper describes a design of low-density parity-check(LDPC) decoder supporting block length 2,304-bit and code rate 1/2 of IEEE 802.16e mobile WiMAX standard. The designed LDPC decoder employs the min-sum algorithm and partially parallel layered-decoding architecture which processes a sub-matrix of $96{\times}96$ in parallel. By exploiting the properties of the min-sum algorithm, a new memory reduction technique is proposed, which reduces check node memory by 46% compared to conventional method. Functional verification results show that it has average bit-error-rate(BER) of $4.34{\times}10^{-5}$ for AWGN channel with Fb/No=2.1dB. Our LDPC decoder synthesized with a $0.18{\mu}m$ CMOS cell library has 174,181 gates and 52,992 bits memory, and the estimated throughput is about 417 Mbps at 100-MHz@l.8-V.

모바일 WiMAX 표준 IEEE 802.16e의 블록길이 2,304 비트, 부호율 1/2을 지원하는 LDPC(low-density parity-check) 복호기를 설계하였다. 설계된 LDPC 복호기는 최소-합(min-sum) 알고리듬과 layered 복호를 기반으로 $96{\times}96$ 크기의 부행렬을 병렬로 처리하는 부분병렬 구조를 갖는다. 최소-합 알고리듬의 특징을 이용하여 메모리 용량을 감소시킬 수 있는 새로운 방법을 고안하여 적용함으로써 검사노드 메모리 용량을 기존의 방법보다 46% 감소시켰다. Verilog HDL로 설계된 LDPC 복호기를 $0.18{\mu}m$ CMOS 셀 라이브러리로 합성한 결과 174,181개의 게이트와 52,992 비프의 메모리로 구현되었으며, Eb/No=2.1dB의 AWGN 채널에 대해 평균 비트 오율 (BER)는 $4.34{\times}10^{-5}$이고, 100 MHz@1.8-V로 동작하여 약 417 Mbps의 성능을 갖는다.

Keywords

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