MIMO LAYERED SPACE-TIME SYSTEM WITH VIRTUAL RECEIVE ANTENNAS

无线通信技术正在成为普通大众的日常必需品。随着互联网使用和多媒体业务的爆炸性增长，对更高数据速率的无线通信系统的需求也在飙升。然而，传统的单天线系统正在达到极限，不能满足这一需求。MIMO分层空时(LST)系统通过使用多个发射和接收天线，可以利用额外的空间资源，远远超过单天线系统的限制。然而，这项技术要求接收天线的数量至少与发射天线的数量相同。由于移动单元的尺寸有限，这样的要求不容易满足，并阻碍了这一前景光明的技术的成熟。本项目旨在通过探索虚拟接收天线的新思想来降低这一苛刻的要求。来自这些虚拟天线的信号是通过对实际接收的信号使用一些信号处理技术来创建的。这项研究的结果将使MIMO LST技术的可行实施和更广泛的传播成为可能。这一想法将针对不同的渠道环境进行彻底的调查。将开发接收器结构，并通过计算机仿真获得其性能。还将就实际执行情况进行初步研究，以便今后进一步利用这一新想法。

Wireless communication technology is becoming a daily necessity for the general public. With the explosive growth of internet usage and multimedia services, the demand for higher data rate wireless communication systems is soaring. However, conventional single antenna systems are reaching the limit and cannot satisfy this need. By using multiple transmit and receive antennas, MIMO Layered Space-Time (LST) systems exploit the additional spatial resource and can reach far beyond the limit of single antenna system. This technology, however, requires the number of receive antennas at least as many as the number of transmit antennas. Being limited in size at the mobile unit, such a requirement cannot be met easily and hinders the maturity of this promising technology. This project aims at reducing this stringent requirement by exploring the novel idea of virtual receive antennas. The signals from these virtual antennas are created by using some signal processing techniques on the actual received signals. The result of this research will allow feasible implementation and wider dissemination of the MIMO LST technology. This idea will be thoroughly investigated for different channel environments. The receiver architecture will be developed and its performance will be obtained by computer simulation. Preliminary study on practical implementation will also be conducted to allow further exploitation of this new idea in the future.