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Approximated Soft-Decision Demapping Algorithm for Coded 4+12+16 APSK

부호화된 4+12+16 APSK를 위한 근사화된 연판정 디매핑 알고리즘

  • 이재윤 (한국전자통신연구원) ;
  • 장연수 (한양대학교 융합전자공학부) ;
  • 윤동원 (한양대학교 융합전자공학부)
  • Received : 2012.07.17
  • Accepted : 2012.08.07
  • Published : 2012.09.30

Abstract

This paper proposes an approximated soft decision demapping algorithm with low computational complexity for coded 4+12+16 amplitude phase shift keying (APSK) in an additive white Gaussian noise (AWGN) channel. To derive the proposed algorithm, we approximate the decision boundaries for 4+12+16 APSK symbols, and then decide the log likelihood ratio (LLR) value for each bit from the approximated decision boundaries. Although the proposed algorithm shows about 0.6~1.1dB degradation on the error performance compared with the conventional max-log algorithm, it gives a significant result in terms of the computational complexity.

본 논문에서는 부호화된 4+12+16 APSK에 대하여 낮은 복잡도를 갖는 근사화된 연판정 디매핑 알고리즘을 제안한다. 제안된 알고리즘을 도출하기 위해 4+12+16 APSK의 결정 경계를 근사화하고, 그 근사화된 결정 경계로부터 각 비트에 대한 LLR 값을 계산한다. 새롭게 제안된 알고리즘은 기존의 max-log 알고리즘보다 곱셈 계산 수를 상당히 줄여 수신기 복잡도를 크게 낮출 수 있으며, 낮은 복잡도로 인한 BER 성능 열화를 약 1.1dB 이하로 줄일 수 있다.

Keywords

References

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