A study of variable channel length for single carrier transmission with decision feedback equalizer

Single Carrier Transmission (SCT) is a competing technique for Orthogonal Frequency Division Multiplexing (OFDM) in Broadband Wireless Systems (BWS). Recent developments in Frequency Domain Fqualization (FDE) using Decision Feedback Equalization (DFE) have greatly improved the system based on the SC technique. This paper presents the comparison of two different variants of both OFDM and SCT techniques, namely OFDM-Cyclic Prefix (OFDM-CP), OFDM-Zero Padding (OFDM-ZP), SC-CP and SC-ZP. SC variants are simulated with Linear Equalizer(LE) and DFE. We have simulated all four techniques for different flat and frequency selective channels. A new block DFE structure is presented which iteratively improves itself and performs better as we increase the number of iterations. Comparison results for BER simulations of both variants of OFDM and SC with LE and DFE verify the supremacy of CP versions of SC-LE and SC-DFE over OFDM-CP and OFDM-ZP.