The 4G and 5G wireless communication systems provide very high date rates operate in mobility regions with large number of users. channel conditions these communications are doubly dispersive which includes time frequency dispersion. OFDM techniques commonly used 4G/5G provides better performance selective channels offer less Inter symbol interference. But Doppler shift introduces the subcarrie...

By both lengthening the transmission interval so that ISI is almost inconsequential and by using combinations of channel eigenfunctions to convey the bits, communications over dispersive channels can be cast as a multiuser detection problem where each bit is assigned its own waveform. For a single dispersive channel – through interference avoidance or some other numerical method – a uniform max...

Hexagonal multicarrier modulation (HMM) system is the technique of choice to overcome the impact of time-frequency dispersive transmission channel. This paper examines the effects of insufficient synchronization (carrier frequency offset, timing offset) on the amplitude and phase of the demodulated symbol by using a projection receiver in hexagonal multicarrier modulation systems. Furthermore, ...

Orthogonal Frequency Division Multiplexing based on Offset Quadrature Amplitude Modulation (OFDM/OQAM) systems are highly sensitive to Carrier Frequency Offset (CFO), especially in doubly selective fading channels. In this paper, by modeling the doubly selective channel with Basis Expansion Model (BEM), we prove the cyclostationarity of the received OFDM/OQAM signal in the presence of CFO. A bl...