High Spectral Efficient and Flexible Next Generation Mobile Communications

In this article we identify and describe the requirements and challenges of next generation mobile communications systems. The so-called fourth generation (4G) aims at throughput rates of more than 100 MBit/s outdoors with high mobility and 1GBit/s indoors. This requires new advanced techniques in the air interface of such a system. We outline new possible techniques and introduce a future basic physical layer concept. The adaptivity to the channel of all the modules in such a possible concept is highlighted. Since the needed large bandwidth for high data rates is a very valuable resource, future communications systems need a high spectrum flexibility. Furthermore, 4G systems will face severe inter-cell interference scenarios that have to be tackled. Both challenges, i.e., spectrum flexibility and inter-cell interference, are discussed in more detail.