THP Scheme with Reduced Noise Enhancement for Multi-User MIMO Systems

摘要

Tomlinson Harashima Precoding (THP) for Multi- User Multiple Input Multiple Output (MU-MIMO) system has been proposed as an effective way to achieve near capacity to the theoretical limit in MU-MIMO channels. In order to achieve better performance, other THP methods such as minimum mean square error (MMSE) THP and lattice reduction aided (LRA) THP are proposed. Those methods outperform the conventional THP, however, the computational complexity also increases. In this paper, we propose a modified THP by new approach using square root to reduce a noise enhancement with less increase of computational complexity. Computer simulation shows that proposed method can achieve better trade-off between bit error rate and computational complexity than MSE THP and LRA THP.%マルチユーザMIMO（MU-MIMO：Multi-User Multiple Input Multiple Output）システムにおいて，MU-MIMO伝送路容量の理論限界に近い伝送路容量を実現する効果的な手法として，Tomlinson Harashima Precoding（THP）手法が提案されている．さらなる伝送性能の改善のために，Minimum Mean Square Error（MMSE）THP手法やLattice Reduction Aided（LRA）THP手法が提案されている．これらの手法は従来のTHP手法と比較して伝送性能は改善されるが，より大きな演算量が必要となる．本稿では，わずかな演算量の増加で実現可能な，平方根を利用して雑音強調を低減する新たなTHP手法を提案する．また，計算機シミュレーションにより，提案手法はMMSETHP手法やLRA THP手法と比較してより良好なビット誤り率と演算量のトレードオフ関係を持つことを示す．