Waveform Diversity for Wireless Communications with Joint Transceiver Multipath Exploitation and Interference Avoidance

多输入多输出（MIMO）无线通信系统，配备了多个发射和接收天线，提供了显着改善的错误性能和增强的容量。 然而，实现MIMO系统的潜力受到衰落、移动性、干扰和低功率要求的影响。 随着ad-hoc网络的迅速发展和超宽带通信的出现，干扰问题日益严重，现有的MIMO无线收发器设计方法要么假设发射机具有完全的信道知识，要么假设发射机不具有信道知识。 后者产生悲观的设计，而前者是不现实的，并可能导致严重的通道失配的情况下，大量的性能损失。 因此，研究人员正在研究MIMO无线系统在不同程度的PARTIAL信道知识下的基本容量和错误性能限制。 相应地，他们正在开发基于部分信道知识的信道自适应MIMO收发器，该收发器在规定的错误概率容限下最小化发射功率并最大化数据速率。正在研究将空时块编码和空时波束形成两者结合以实现干扰避免和对不完美信道知识的鲁棒性的混合方案。正在开发的先进算法将深刻改变MIMO技术，并直接影响无线多天线通信的鲁棒性和带宽效率。

Multi-input multi-output (MIMO) wireless communication systems, equipped with multiple transmit and receive antennas, offer dramatically improved error performance and enhanced capacity. However, realizing the potential of MIMO systems is countered by the effects of fading, mobility, interference, and low-power requirements. The problem of interference is exacerbated by the proliferation of ad-hoc networks and the emergence of ultra-wideband communications.Existing approaches to MIMO wireless transceiver design assume either perfect channel knowledge or no channel knowledge at the transmitter. The latter yields pessimistic designs, while the former is unrealistic and can result in substantial performance losses in cases of severe channel mismatch. Thus, the researchers are investigating the fundamental capacity and error performance limits of MIMO wireless systems for varying degrees degrees of PARTIAL channel knowledge. Correspondingly, they are developing channel-adaptive MIMO transceivers based on partial channel knowledge that minimize transmit-power and maximize data rates at a prescribed error probability margin. Hybrid schemes are being researched that incorporate both space-time block coding and space-time beam forming to effect interference avoidance and robustness to imperfect channel knowledge. The advanced algorithms under development will profoundly alter MIMO technology and directly impact the robustness and bandwidth efficiency of wireless multi-antenna communications.