This paper considers orthogonal frequency division multiplexing (OFDM) systems with coherent and incoherent demodulation techniques in mobile radio channels with high terminal velocities. Coherent demodulated systems, using a scattered pilot based channel estimation or a decision directed channel estimation approach, will be compared in terms of bit error rate (BER) performance and hardware complexity with an incoherent system with differential amplitude and phase shift keying (DAPSK) modulation schemes. It will be shown, that in high mobility scenarios, differential modulation schemes together with incoherent demodulation leads to an useful trade off between performance and hardware consumption. The hardware complexity results are acquired from field programmable gate array (FPGA) implementations.
['Nico Toender', 'Sebastian Georgi', 'Hermann Rohling']
Low-Complexity OFDM System with High Mobility Using DAPSK Schemes