Fast Link Adaptation for MIMO OFDM

We investigate link-quality metrics (LQMs) based on raw bit-error-rate, effective signal-to-interference-plus-noise ratio, and mutual information (MI) for the purpose of fast link adaptation (LA) in communication systems employing orthogonal frequency-division multiplexing and multiple-input-multiple-output (MIMO) antenna technology. From these LQMs, the packet error rate (PER) can be estimated and exploited to select the modulation and coding scheme (MCS) among a class of candidate MCSs that achieves the maximum throughput for the current channel state under a specified target PER objective. We propose a novel MI-based LQM and compare the PER-estimation accuracy obtained with this LQM with that resulting from using other LQMs by means of comprehensive Monte Carlo simulations. Search methods for the MCS in the class that is most suitable for a given channel state are presented. An algorithm for obtaining a practical upper bound on the throughput of any LA scheme is proposed. The investigated LQMs are applied to the IEEE 802.11n standard with a 2 × 2 MIMO configuration and practical channel estimation. The proposed MI-based LQM yields the highest PER estimation accuracy, and its throughput shows only 1.7 dB signal-to-noise-ratio (SNR) loss with respect to the upper bound but up to 9.5 dB SNR gain, compared to the MCS maximizing the throughput for the current noise variance.

[1]  Stephan ten Brink,et al.  Design of low-density parity-check codes for modulation and detection , 2004, IEEE Transactions on Communications.

[2]  Lars Torsten Berger.  Performance of Multi-Antenna Enhanced HSDPA , 2005 .

[3]  Philippe J. Sartori,et al.  Error prediction for adaptive modulation and coding in multiple-antenna OFDM systems , 2006, Signal Process..

[4]  Wolfgang Zirwas,et al.  Per-prediction for PHY mode selection in OFDM communication systems , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[5]  Rohit U. Nabar,et al.  Introduction to Space-Time Wireless Communications , 2003 .

[6]  Dariush Divsalar,et al.  Code Performance as a Function of Block Size , 1998 .

[7]  Angeliki Alexiou,et al.  Link performance models for system level simulations of broadband radio access systems , 2005, 2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications.

[8]  Sumei Sun,et al.  Link adaptation based on adaptive modulation and coding for multiple-antenna OFDM system , 2008, IEEE Journal on Selected Areas in Communications.

[9]  Bernard H. Fleury,et al.  Mutual Information Metrics for Fast Link Adaptation in IEEE 802.11n , 2008, 2008 IEEE International Conference on Communications.

[10]  J. Cavers,et al.  Variable-Rate Transmission for Rayleigh Fading Channels , 1972, IEEE Trans. Commun..

[11]  Andreas Springer,et al.  Novel SINR-to-CQI Mapping Maximizing the Throughput in HSDPA , 2007, 2007 IEEE Wireless Communications and Networking Conference.

[12]  Wolfgang Zirwas,et al.  Misunderstandings about link adaptation for frequency selective fading channels , 2002, The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[13]  Sanjiv Nanda,et al.  Packet error probability prediction for system level simulations MIMO-OFDM based 802.11n WLANs , 2005, IEEE International Conference on Communications, 2005. ICC 2005. 2005.

[14]  Robert F. H. Fischer,et al.  Adaptive Interleaving for Bit-Interleaved Coded Modulation , 2011 .

[15]  Robert W. Heath,et al.  Adaptation in Convolutionally Coded MIMO-OFDM Wireless Systems Through Supervised Learning and SNR Ordering , 2010, IEEE Transactions on Vehicular Technology.

[16]  Kenneth A. Stewart,et al.  Link Performance Abstraction based on Mean Mutual Information per Bit (MMIB) of the LLR Channel , 2007 .

[17]  Yang-Seok Choi,et al.  A Pragmatic PHY Abstraction Technique for Link Adaptation and MIMO Switching , 2008, IEEE Journal on Selected Areas in Communications.

[18]  M. Lamarca,et al.  Indicators for PER prediction in wireless systems: A comparative study , 2005, 2005 IEEE 61st Vehicular Technology Conference.

[19]  S. Nanda,et al.  Frame error rates for convolutional codes on fading channels and the concept of effective E/sub b//N/sub 0/ , 1998 .

[20]  Tung-Sang Ng,et al.  Adaptive interleaving for OFDM in TDD systems , 2000, 2000 IEEE International Conference on Communications. ICC 2000. Global Convergence Through Communications. Conference Record.

[21]  J.M. Cioffi,et al.  Low Complexity BICM-OFDM-based MIMO Receiver using Successive Interference Cancelation , 2006, 2006 Wireless Telecommunications Symposium.

[22]  Fei Peng,et al.  Adaptive Modulation and Coding for IEEE 802.11n , 2007, 2007 IEEE Wireless Communications and Networking Conference.