EVM Measurement Algorithm for OFDM Transmitters

OFDM technology has been widely adopted as the mainstream physical technology in B3G and 4G systems for better utilization ratio of spectrum, as a result, the RF parts of B3G and 4G systems have to face greater challenges. At the same time, we need find an effective and efficient method to evaluate the RF performance of B3G and 4G systems. The error vector magnitude (EVM) is suitable to serve as a key parameter to evaluate the RF performance of OFDM transmitters according to the experience of RF conformance test of 2G system. In this paper the research model of EVM measurement for B3G and 4G systems is set up. Then an accurate, robust EVM measurement algorithm is proposed, which is quite easy to be applied into practice. According to the comparison between the simulation results and the measurement results with professional test instrument, the algorithm can accomplish EVM measurement; moreover, it is competent to be a key measurement algorithm in RF test instruments for OFDM transmitters