Key Algorithms for Accurate GSM EDGE EVM Measurement on ATE Platform

There´s a high demand for accurate, fast, yet easy to implement GSM EDGE EVM algorithm in final production test on ATE platforms. This paper proposes two key algorithms, one for symbol timing recovery, and the other for frequency offset correction. The symbol timing recovery algorithm is based upon constructing the eye diagram on the interpolated EDGE signal and finding the minimum magnitude variance among different sample positions. The frequency offset correction algorithm is realized by brutal demodulation of the EDGE signal, followed by a correction of plusmnpi/4 phase discontinuity, and a linear regression to de-embed frequency offset from the phase noise. Test programs using these algorithms show good correlation with bench equipment when testing a real transceiver device