Research On The Methods Of Single Carrier Frequency Domain Equalization

Eliminating the Inter-Symbol interference is the emphasis in the area of wireless communication. Orthogonal frequency division multiplexing (OFDM) and single-carrier frequency domain equalization (SC-FDE) are both effective methods and used widely. OFDM is famous for high spectrum efficiency and strong anti-interference ability, but its high PAPR and sensitive channel offset can’t be ignored. In contrast, SC-FDE has good performance in these two aspects.This paper discusses two algorithms in linear equalization:zero forcing (ZF) and minimum mean square error (MMSE). ZF is simple, but ignores the noise in the wireless channel. So when the wireless channel is terrible, the noise will be amplified and SNR of the system will be low. MMSE takes noise into account, and calculates the coefficients by minimizing the error. ZF and MMSE are also simulated in this paper.In the nonlinear equalization, decision feedback equalization (DFE) is widely used method. DFE includes hybrid time-frequency domain decision feedback equalization (FD-DFE), decision feedback equalization with noise prediction (DFE-NP) and bidirectional decision feedback equalization with noise prediction (BiDFE-NP). This paper proposes an improved simplified hard decision feedback equalizer (S-HDFE) with low complexity to improve the performance of BiDFE-NP. S-HDFE is simulated on both Rayleigh fading channel and scattering channel.