单用户MIMO系统在LTE项目中的应用研究

摘要

Orthogonal Frequency-Division Multiplexing is a multi-carrier modulation scheme,where information symbols are transmitted in parallel over the channel by using a set of subcarriers.One of the main advantages is increased robustness against frequency selective fading and narrowband interference.In this paper we study the performance of two dual-codeword Single-User Multiple-Input Multiple-Output(SU-MIMO) schemes,i.e.Per Antenna Rate Control(PARC) and Precoded MIMO(PREC),in an OFDM deployment.For PARC we consider 2x2 and 4x4 antenna configurations and for Precoded MIMO 4x4 antenna configuration only.Our study is performed with a downlink Long Term Evolution(LTE) system simulator.The results indicate that in terms of average sector throughput the four-stream schemes outperform the dual-stream scheme by approximately 75%~90%.Moreover,the four-stream schemes have significant coverage gain compared to the dual-stream scheme.%OFDM是一种多载波调制方案,信息在并行信道里通过一系列的子载波传播。主要的优点是增加了抑制频选衰落和窄带干扰的鲁棒性。本文中我们主要介绍单用户MIMO,也就是（SU-MIMO）方案,例如：单天线速率控制（PARC）,和预编码MIMO（PREC）。在PARC中,我们主要考虑2×2和4×4两种天线结构;在PREC中,我们考虑4×4这一种单一情况。本文主要是研究下行链路的长期演进（LTE）。结果显示,就平均扇区吞吐量而言,四码流方案要优于双码流方案接近75%～90%,此外四码流方案有着明显的覆盖增益。