TY - JOUR
T1 - Towards the performance of ML and the complexity of MMSE
T2 - A hybrid approach for multiuser detection
AU - Shim, Byonghyo
AU - Choi, Jun Won
AU - Kang, Insung
N1 - Funding Information:
Manuscript received June 27, 2011; revised February 21, 2012; accepted April 18, 2012. The associate editor coordinating the review of this paper and approving it for publication was Y. J. Zhang. B. Shim is with the School of Information and Communication, Korea University, Seoul, Korea (e-mail: bshim@korea.ac.kr). J. Choi and I. Kang are with Qualcomm Inc., CA 92121 USA (e-mail: {junwonc, insungk}@qualcomm.com). This work is supported by the Basic Science Research Program through the National Research Foundation (NRF) funded by the Ministry of Education, Science and Technology (MEST) (No. 2011-0012525) and second Brain Korea 21 project. Digital Object Identifier 10.1109/TWC.2012.051512.111220
PY - 2012
Y1 - 2012
N2 - In this paper, we consider a low-complexity multiuser detection for downlink of high speed packet access (HSPA) of universal mobile telecommunications system (UMTS). Instead of attempting to perform maximum likelihood (ML) detection of all users in multiple cells, which is impractical for battery powered mobile receiver, we utilize interference cancelled chips obtained from iterative linear minimum mean square error (LMMSE) estimation to perform a near ML detection in a reduced dimensional system. As a result, the worst case complexity of the detection process, achieved by the closest lattice point search (CLPS), is bounded to a controllable level irrespective of multipath spans. Furthermore, by exploiting the LMMSE estimate in tightening the hypersphere condition of the CLPS algorithm so called sphere decoding, we achieve significant improvement in search complexity. From simulations on realistic downlink communication scenario in HSPA systems, we show that the proposed method offers substantial performance gain over conventional receiver algorithms with reasonable complexity.
AB - In this paper, we consider a low-complexity multiuser detection for downlink of high speed packet access (HSPA) of universal mobile telecommunications system (UMTS). Instead of attempting to perform maximum likelihood (ML) detection of all users in multiple cells, which is impractical for battery powered mobile receiver, we utilize interference cancelled chips obtained from iterative linear minimum mean square error (LMMSE) estimation to perform a near ML detection in a reduced dimensional system. As a result, the worst case complexity of the detection process, achieved by the closest lattice point search (CLPS), is bounded to a controllable level irrespective of multipath spans. Furthermore, by exploiting the LMMSE estimate in tightening the hypersphere condition of the CLPS algorithm so called sphere decoding, we achieve significant improvement in search complexity. From simulations on realistic downlink communication scenario in HSPA systems, we show that the proposed method offers substantial performance gain over conventional receiver algorithms with reasonable complexity.
KW - Babai point
KW - Closest lattice point search
KW - multiuser detection
KW - noncausal path metric
KW - sphere decoding
UR - http://www.scopus.com/inward/record.url?scp=84864128981&partnerID=8YFLogxK
U2 - 10.1109/TWC.2012.051512.111220
DO - 10.1109/TWC.2012.051512.111220
M3 - Article
AN - SCOPUS:84864128981
SN - 1536-1276
VL - 11
SP - 2508
EP - 2519
JO - IEEE Transactions on Wireless Communications
JF - IEEE Transactions on Wireless Communications
IS - 7
M1 - 6204012
ER -