Fourth generation (4G) mobile communication systems will need wider band-width channels and improved spectrum efficiency to achieve the specified LTE-advanced 100Mbps (mobile) and 1Gbps (fixed) wireless transmission target rate. The next generation of wireless basestations will also need to be powered from renewable sources, particularly in developing countries. A new generation of components, circuits, algorithms and transmission structures will therefore be required to meet the wider bandwidth and the lower energy requirements. This thesis addresses the transmitter chain, which dominates the basestation power budget. In particular we consider pre-conditioning algorithms for a new generation of high efficiency radio frequency power amplifiers (RFPA).