应对MIMO测试挑战

为了得到MIMO OTA性能的完整描述，需要两支发射天线在各个入射角方向对UE天线进行三维的测试，而且还需要各种极化方式的组合。

罗德与施瓦茨的双通道测试法的另一大优点是可以在原来的SISO测试系统基础上方便地进行升级，只需增加第二个角度定位器控制系统以及第二支测试天线。大大地降低了成本，也满足了业内客户的需求。

4. 小结

现在无线通信系统需要提供越来越高的数据速率。通过使用多天线系统(典型的MIMO)，可以使数据速率和信道容量有了比较大的提升。因此MIMO系统已广泛应用于多种移动通信标准，也成为了未来移动通信标准的必选项目。本文在介绍MIMO原理和不同通信体制MIMO应用的基础上，给出了R&S公司的相应测试解决方案。R&S的信号源、无线综测仪都为双通道设计，大大方便了MIMO的测试。基于示波器的MIMO发射机测试和基于双通道测量法的MIMO OTA测试也很有特色。MIMO给测试带来了新的挑战，R&S公司全面的测试解决方案可以帮助客户迎接这些挑战。

5. 参考文献

* HSPA+

[1] Rohde & Schwarz: HSPA+ Technology Introduction, Application Note 1MA121, March 2008

* LTE

[2] 3GPP TS 36.211 V8.4.0; Physical Channels and Modulation (Release 8)

[3] Rohde & Schwarz: UMTS Long Term Evolution (LTE) Technology Introduction, Application Note 1MA111, September 2008

[4] Rohde & Schwarz: LTE Measurement Guide, Application Note RSI004, August

　　2007

[5] Rohde & Schwarz: RF Chipset Verification for UMTS LTE with SMU200A and FSQ, Application Note 1MA138, November 2008

[6] Rohde & Schwarz: E-UTRA Base Station Testing acc. to 3GPP TS 36.141, Application Note 1MA134, December 2008

[7] Rohde & Schwarz: LTE Downlink MIMO Verification with R&S?SMU200A and R&S?FSQ, Application Note 1MA143, June 2009

* WLAN

[9] IEEE: 802.11n?/D8.0: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, Amendment 5. Enhancements for Higher Throughput, January 2009

[10] Rohde & Schwarz: 802.11ac Technology Introduction, White Paper 1MA192, March 2012

* MIMO

[11] H. Jafarkhani: “Space-Time Coding Theory and Practice”, Cambridge, 2000

[12] M. Jankiraman: “Space-Time Codes and MIMO Systems” Artech House, (2004)

[13] Rohde & Schwarz: Introduction to MIMO System, Application Note 1MA142, 2008

* OTA

[14] CTIA Test Plan for Mobile Station Over the Air Performance; Rev. 3.1; 2011-01.

[15] 3GPP TS 34.114; User Equipment (UE) / Mobile Station (MS) Over The Air (OTA) antenna performance; V8.4.0 (2010-06).

作者：尤嘉

罗德与施瓦茨中国有限公司