Low-Complexity Soft-MIMO Detection Algorithm Based on Ordered Parallel Tree-Search Using Efficient Node Insertion

Title & Authors
Low-Complexity Soft-MIMO Detection Algorithm Based on Ordered Parallel Tree-Search Using Efficient Node Insertion
Kim, Kilhwan; Park, Jangyong; Kim, Jaeseok;

Abstract
This paper proposes an low-complexity soft-output multiple-input multiple-output (soft-MIMO) detection algorithm for achieving soft-output maximum-likelihood (soft-ML) performance under max-log approximation. The proposed algorithm is based on a parallel tree-search (PTS) applying a channel ordering by a sorted-QR decomposition (SQRD) with altered sort order. The empty-set problem that can occur in calculation of log-likelihood ratio (LLR) for each bit is solved by inserting additional nodes at each search level. Since only the closest node is inserted among nodes with opposite bit value to a selected node, the proposed node insertion scheme is very efficient in the perspective of computational complexity. The computational complexity of the proposed algorithm is approximately 37-74% of that of existing algorithms, and from simulation results for a $\small{4{\times}4}$ system, the proposed algorithm shows a performance degradation of less than 0.1dB.
Keywords
Soft-MIMO Detection;Parallel Tree-Search;Node Insertion;SQRD;Empty-Set Problem;
Language
Korean
Cited by
References
1.
3rd Generation Partnership Project (3GPP), "Technical specification group radio access network; evolved universal terrestrial radio access (E-UTRA); physical channels and modulation (Release 10)," Dec. 2010.

2.
IEEE 802.16 Task Group m (TGm), "IEEE 802.16m system description document (SDD)," Dec. 2010.

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

4.
C. Studer, A. Burg, and H. Bölcskei, "Soft-output sphere decoding: algorithms and VLSI implementation," IEEE J. Sel. Areas Commun., vol. 26, no. 2, pp. 290-300, Feb. 2008.

5.
K. Kim, Y. Jung, S. Lee, and J. Kim, "Efficient list extension algorithm using multiple detection orders for soft-output MIMO detection," IEICE Trans. Commun., vol. E95-B, no. 3, pp. 898-912, Mar. 2012.

6.
E. Viterbo and J. Boutros, "A universal lattice code decoder for fading channels," IEEE Trans. Inform. Theory, vol. 45, no. 5, pp. 1639-1642, Jul. 1999.

7.
K. W. Wong, C. Y. Tsui, R. S. K. Cheng, and W. H. Mow, "A VLSI architecture of a K-best lattice decoding algorithm for MIMO channels," in Proc. IEEE Int. Symp. Circuits and Syst. (ISCAS), pp. 273-276, May. 2002.

8.
M. Higashinaka, K. Motoyoshi, A. Okazaki, T. Nagayasu, H. Kubo, and A. Shibuya, "Likelihood estimation for reducedcomplexity ML detectors in a MIMO spatial-multiplexing system," IEICE Trans. Commun., vol. E91-B, no. 3, pp. 837-847, Mar. 2008.

9.
L. G. Barbero and J. S. Thompson, "Extending a fixed-complexity sphere decoder to obtain likelihood information for turbo-MIMO systems," IEEE Trans. Veh. Technol., vol. 57, no. 5, pp. 2804-2814, Sep. 2008.

10.
S. Bahng, Y. Park, and J. Kim, "QR-LRL detection for spatially multiplexed MIMO systems," IEICE Trans. Commun., vol. E91-B, no. 10, pp. 3383- 3386, Oct. 2008.

11.
D. L. Milliner, E. Zimmermann, J. R. Barry, and G. Fettweis, "A fixed-complexity smart candidate adding algorithm for soft-output MIMO detection," IEEE J. Sel. Topics Sig. Process., vol. 3, no. 6, pp. 1016-1025, Dec. 2009.

12.
J. Kim, Y. Park, and S. Bahng, "Efficient soft-output generation method for spatially multiplexed MIMO systems," IEICE Trans. Commun., vol. E92-B, no. 11, pp. 3512-3515, Nov. 2009.

13.
J. Kim, S. Bahng, and Y. Park, "A signal detection method based on the double detection for spatially multiplexed MIMO systems," KICS J., vol. 34, no. 6, pp. 634-641, Jun. 2009.

14.
T. H. Im, I. Park, J. M. Kim, J. Yi, J. W. Kim, S. Yu, and Y. S. Cho, "A new signal detection method for spatially multiplexed MIMO systems and its VLSI implementation," IEEE Trans. Circuits Syst. II: Express Briefs, vol. 56, no. 5, pp. 399-403, May. 2009.

15.
T. H. Im, J. Kim, and Y. S. Cho, "A QOC signal detection method for spatially multiplexed MIMO systems," KICS J., vol. 35, no. 9, pp. 771-777, Sep. 2010.

16.
Z. Lei, Y. Dai, and S. Sun, "A low complexity near ML V-BLAST algorithm," in Proc. IEEE Veh. Technol. Conf. (VTC) - Fall, pp. 942-946, Sep. 2005.

17.
L. G. Barbero and J. S. Thompson, "Fixing the complexity of the sphere decoder for MIMO detection," IEEE Trans. Wireless Commun., vol. 7, no. 11, pp. 2131-2142, Jun. 2008.

18.
G. J. Foschini, "Layered space-time architecture for wireless communication in a fading environment when using multiple antennas," Bell Lab. Tech. J., vol. 1, no. 2, pp. 41-59, Aug. 1996.

19.
D. Wubben, R. Bohnke, J. Rinas, V. Kuhn, and K. D. Kammeyer, "Efficient algorithm for decod- ing layered space-time codes," IEE Electron. Lett., vol. 37, no. 22, pp. 1348-1350, Oct. 2001.