In this paper, the short-term time variation of wideband channels is investigated based on some extensions to the interim beyond-3G (IB3G) spatial channel model (SCM), which was developed for a multi-input multi-output (MIMO) system and used within the European WINNER project. These extensions mainly include some modifications of the generation of the wideband fast fading channel matrix, such as the consideration of the time variant sub-path phases at the mobile station (MS), the consideration of the powers of the time variant multi-paths, and the generation of different last bounce distances (LBDs) for the mid-paths within each path. In order to measure the short-term time variation of the wideband channels, this paper redefines the correlation matrix distance (CMD) metric, which was originally for the narrowband fast fading scenario. The simulated CMD generated from the newly extended Third Generation Partnership Project (NE-3GPP) spatial channel model (SCM) compares better to the measurements taken in the FLOWS project than that of the IB3G SCM.