The 3rd Generation wireless communication systems, such as WCDMA and cdma2000, have been successfully combining the traditional mobile applications mainly serving circuit switched voice services with the IP-Based internet-type of packet data services. Currently mobile users can enjoy not only voice calls, but also video sharing, instant messaging, broadcasting, multi-media services, and location-based services. This presentation addresses two fundamental limitations in wireless system performances.  The one is the maximum achievable spectral efficiency, generally known as a Shannon Bound or channel capacity, for the given bandwidth and signal to noise ratio.  The other bound is the interference bound germane to cellular system, which is the power limitation avoiding the degradation of the other average cells or sectors throughput. Brief descriptions on MIMO and interference mitigation method in long-term evolution (LTE) to increase the spectral efficiency and reduce the interference to other cells then follows.
The requirements and schedule for IMT-Advanced are introduced and component technologies considered in further enhancement of LTE, known as LTE-Advanced, are described.