An improved OFDM-MSK system for wireless communications

As a well attractive modulation scheme, minimum-shift keying (MSK) has a fast roll-off side-lobe spectrum. Because of this excellent property, we introduce MSK into the conventional OFDM to form an improved OFDM-MSK system. The new system can effectively overcome the carrier frequency offset (CFO), mitigate the interference among the sub-carriers. And two kinds of OFDM-MSK receiver are discussed in detail. At the same time, two FFT-based sampling modes (mode A and mode B) are also proposed and analyzed. And a practical OFDM-MSK structure design is given. Simulation results show that when SNR is high, the BER performance of OFDM-MSK systems outperforms that of OFDM-QPSK systems over AWGN and Rayleigh wireless fading channels.