Introduction:Advanced OFDM (Orthogonal Frequency Division Multiplex) technologies impose additional challenges and requirements for testing new wireless communication devices and systems. This paper compares and contrasts traditional single-carrier modulation schemes with multi-carrier OFDM schemes to understand the test equipment and measurement considerations when using modern vector signal generators and analyzers. It covers in detail spectrum, power, and modulation quality measurements and techniques for R&D and high-speed production test applications. The paper covers testing of both SISO (single-input, single-output) and MIMO (multiple-input, multiple-output) communications systems used in 802.11n WLAN, 802.16e mobile-WiMAX Wave 2, which are also applicable to future LTE and UMB cellular standards.