To achieve the target data rate of Long Term Evolution (LTE), many new techniques are necessary. Multiple-Input Multiple-Output (MIMO) is one key technique among them due to its ability to enhance the radio channel capacity of cellular systems without extra spectrum cost. Cross-layer has been thought as one of the most efficient ways for multimedia communications over wireless networks. In this paper a proposed cross-layer approach to solve the problem of switching between MIMO multiplexing and diversity modes. We impose the LTE MIMO constraint of selecting only one MIMO mode per user per transmission time interval (TTI). The results show that, the proposed adaptive method achieves the Quality of Service (QoS) guarantees for the Guaranteed Bit Rate (GBR) traffic.