應用於4G具迭代解碼之多天線位元交錯調變-編碼系統之新型設計

Abstract

4G 需要有遠優於3G 系統的頻譜效率，20 bps/Hz 是設計目標。欲達此目標，預期需要 具更高天線數量的MIMO (multiple input, multiple output)系統，然而高天線數量將使手機 的天線設計更加困難，基頻訊號處理的複雜度亦更加提高。另一方面，通道編解碼器、 MIMO 調變/解調器必須同時作最佳設計並充分使用通道狀態信息(channel state information)，以達到最高的品質。在眾多的4G 議題中，本計畫將針對實體層之通道編 解碼、MIMO 調變/解調器作最佳設計以達到最高的品質。更明確的說，本計畫將針對 具迭代解碼 (iterative decoding) 之多天線位元交錯調變編碼 (bit-interleaved coded-modulation)系統作完整設計。雖然迭代解碼在3G 的MIMO BICM 系統中尚未使 用，在4G 超高的品質與品頻譜效率要求下，它勢必成為4G 系統中不可或缺的關鍵技 術。本計畫的研究將包括新型映射法則(mapping rule)，最佳MIMO RF 參數估計，新型 低複雜度、接近ML (maximum likelihood)效能的MIMO 偵測器及新型MIMO pre-coder。

Very high spectral efficiency is one of the salient features for 4G systems; 20 bps/Hz is the targeted value. In order to achieve this, it is anticipated to use more antennas at both base station and mobile stations (MIMO), but that significantly increases the complexity of base-based signal processing and antenna design at the mobile station. In addition, joint optimal design of channel coding/decoding and MIMO detectors with the help of channel state information is essential to have the best link performance. In this project, we investigate the important issue of joint design of channel coding/decoding and MIMO detectors for bit-interleaved coded modulation with iterative decoding (BICM-ID). BICM-ID has been considered as one of the key enabling PHY technologies for 4G systems, although it was not used in 3G because of the complexity. In particular, the research topics include a new labeling design for MIMO systems, joint optimum inner receiver design for MIMO with direct-conversion RF architecture, and a new approaching ML low-complexity MIMO detector and pre-coder based on channel factorization.