Low-Complexity Soft-Output Sphere Decoding with Modified Repeated Tree Search Strategy

Many solutions for detecting signals transmitted over flat-faded multiple input multiple output (MIMO) channels have been proposed, e.g., the zero-forcing (ZF), minimum mean squared error (MMSE), sphere decoding (SD) algorithms, to name a few. These approaches however suffer from either unsatisfactory performance or high complexity. In this paper, we focus on the soft-output SD algorithm and propose a modification on the repeated tree search (RTS) strategy. It is shown that our modification can maintain a fixed upper limit in decoding complexity and results in a good performance-complexity tradeoff.

[1]  Alexander Vardy,et al.  Closest point search in lattices , 2002, IEEE Trans. Inf. Theory.

[2]  Franz Hlawatsch,et al.  Efficient detection algorithms for MIMO channels: a geometrical approach to approximate ML detection , 2003, IEEE Trans. Signal Process..

[3]  Preben E. Mogensen,et al.  On the Design of a MIMO-SIC Receiver for LTE Downlink , 2008, 2008 IEEE 68th Vehicular Technology Conference.

[4]  Zhan Guo,et al.  Algorithm and implementation of the K-best sphere decoding for MIMO detection , 2006, IEEE Journal on Selected Areas in Communications.

[5]  Helmut Bölcskei,et al.  Soft-output sphere decoding: algorithms and VLSI implementation , 2008, IEEE Journal on Selected Areas in Communications.

[6]  Claus-Peter Schnorr,et al.  Lattice Basis Reduction: Improved Practical Algorithms and Solving Subset Sum Problems , 1991, FCT.

[7]  K. Kammeyer,et al.  Efficient algorithm for decoding layered space-time codes , 2001 .

[8]  Yongbin Wei,et al.  A survey on 3GPP heterogeneous networks , 2011, IEEE Wireless Communications.

[9]  Gerhard Fettweis,et al.  A Fixed-Complexity Smart Candidate Adding Algorithm for Soft-Output MIMO Detection , 2009, IEEE Journal of Selected Topics in Signal Processing.

[10]  Georgios B. Giannakis,et al.  Approaching MIMO channel capacity with reduced-complexity soft sphere decoding , 2004, 2004 IEEE Wireless Communications and Networking Conference (IEEE Cat. No.04TH8733).

[11]  Byonghyo Shim,et al.  Joint Modulation Classification and Detection Using Sphere Decoding , 2009, IEEE Signal Processing Letters.

[12]  Stephan ten Brink,et al.  Achieving near-capacity on a multiple-antenna channel , 2003, IEEE Trans. Commun..

[13]  U. Fincke,et al.  Improved methods for calculating vectors of short length in a lattice , 1985 .

[14]  Joseph R. Cavallaro,et al.  Architecture design and implementation of the increasing radius - List sphere detector algorithm , 2009, 2009 IEEE International Conference on Acoustics, Speech and Signal Processing.

[15]  A. Burg,et al.  VLSI implementation of MIMO detection using the sphere decoding algorithm , 2005, IEEE Journal of Solid-State Circuits.

[16]  Takahiro Asai,et al.  Performance of Advanced Receiver Employing Interference Rejection Combining to Suppress Inter-Cell Interference in LTE-Advanced Downlink , 2011, 2011 IEEE Vehicular Technology Conference (VTC Fall).

[17]  A. Burg,et al.  VLSI implementation of the sphere decoding algorithm , 2004, Proceedings of the 30th European Solid-State Circuits Conference.