Efficiency increase of information services in3G and 4G networks, using MIMO-systems

The basic idea of a CDMA system to overcome the multipath problem is built on the fact that a spread spectrum signal has a much wider bandwidth occupancy than its original baseband signal, such that the spread spectrum signal will offer a unique property that multipath diversity can be made possible due to its excellent time resolution derived from its very wide bandwidth signaling. A RAKE receiver can be used to resolve different multipath returns individually and combine them again in a coherent or non-coherent way, to achieve the multipath diversity capability, which has become one of the most important technical features that make CDMA a very attractive multiple access technology for 2G and 3G wireless communications.