Soft-Decision Algorithm with Low Complexity for MIMO Systems Using High-Order Modulations

Title & Authors
Soft-Decision Algorithm with Low Complexity for MIMO Systems Using High-Order Modulations
Lee, Jaeyoon; Kim, Kyoungtaek;

Abstract
In a log likelihood ratio(LLR) calculation of the detected symbol, multiple-input multiple-output(MIMO) system applying an optimal or suboptimal algorithm such as a maximum likelihood(ML) detection, sphere decoding(SD), and QR decomposition with M-algorithm Maximum Likelihood Detection(QRM-MLD) suffers from exponential complexity growth with number of spatial streams and modulation order. In this paper, we propose a LLR calculation method with very low complexity in the QRM-MLD based symbol detector for a high order modulation based $\small{N_T{\times}N_R}$ MIMO system. It is able to approach bit error rate(BER) performance of full maximum likelihood detector to within 1 dB. We also analyze the BER performance through computer simulation to verify the validity of the proposed method.
Keywords
MIMO;LLR;ML;QRM-MLD;BER;
Language
Korean
Cited by
1.
밀리미터파 5G 이동통신을 위한 물리계층 모뎀의 구현,김준우;방영조;박윤옥;김일규;김태중;

한국통신학회논문지, 2016. vol.41. 1, pp.51-57
2.
중앙 집중형 밀리미터파 기반 다중 스팟 빔 셀룰러 시스템,박순기;최용석;김태중;

한국통신학회논문지, 2016. vol.41. 3, pp.285-297
References
1.
Y. S. Cho, J. Kim, W. Y. Yang, and C. G. Kang, MIMO-OFDM Wireless Communications with MATLAB, 1st Ed., Jone Wiley & Sons, 2010.

2.
B. Steingrimsson, Z. Q. Luo, and K. M. Wong, "Soft quasi-maximum-likelihood detection for multile-antenna wireless channels," IEEE Trans. Signal Process., vol. 51, no. 11, pp. 2710-2719, Nov. 2003.

3.
J. Lee, Y. Jang, and D. Yoon, "Approximated soft-decision demapping algorithm for coded 4+12+16 APSK," J. KICS, vol. 37, no. 9, pp. 738-745, Sept. 2012.

4.
M. Zhang and S. Kim, "Performance enhancement by scaling soft bit information of APSK," J. KICS, vol. 38, no. 10, pp. 858-866, Oct. 2013.

5.
I. Kang, Y. Kim, J. Seo, H. Kim, and H. Kim, "Performance analysis of a bit mapper of the dual-polarized MIMO DVB-T2 system," J. KICS, vol. 38, no. 9, pp. 817-825, Sept. 2012.

6.
C. Studer, A. Burg, and H. Bolcskei, "Soft-output sphere decoding: algorithms and VLSI implementation," IEEE J. Select. Areas Commun., vol. 26, no. 2, pp. 290-300, Feb. 2008.

7.
C. Yoon and H. Lee, "Implementation of low-complexity MIMO detector and efficient soft-output demapper for MIMO-OFDM-based wireless LAN systems," EURASIP J. Wireless Commun. Netw., vol. 143, May 2013.

8.
X. F. Qi and K. Holt, "A lattice-reductionaided soft demapper for high-rate coded MIMO-OFDM systems," IEEE Signal Process. Lett., vol. 14, no. 5, pp. 305-308, May 2007.

9.
B. Yang and J. F. Bohme, "Rotation-based RLS algorithms: Unified derivations, numerical properties, and parallel implementations," IEEE Trans. Signal Process., vol. 40, no. 5, pp. 1151-1167, May 1992.

10.
B. M. Hochwald and S. Brink, "Achieving near-capacity on a multiple-antenna channel," IEEE Trans. Commun., vol. 51, no. 3, pp. 389-399, Mar. 2003.