OFDM-CPM for Wireless Communications

The discussion of 4G wireless systems is incomplete without OFDM. This book presents a new class of OFDM signals that have the potential of mitigating most of the ill effects of the wireless channels. We name this new class of signals as OFDM-CPM that uses the concept of correlated phase states to improve the bit error rate performance over conventional OFDM signals such as OFDM-PSK, -QAM, -DPSK etc. In OFDM-CPM signals, we systematically introduce correlation amongst adjacent symbols using a well defined mapping process. A number of optimum and suboptimum receivers are designed and their error performance is evaluated over multipath fading channels - both indoor and outdoor. We show that all the OFDM-CPM systems out perform conventional OFDM systems by a substantial margin. The proposed systems are also power efficient and we show that it is possible to design such OFDM-CPM systems that have low peak to average power ratio. In short, OFDM-CPM is a strong candidate for future wireless and mobile communication systems.