On the comparison between conventional ofdm and mse-ofdm systems

Abstract

A new multi-symbol encapsulated orthogonal frequency division multiplexing (MSE-OFDM) system is proposed, in which one cyclic prefix (CP) is used for a frame of multiple OFDM symbols. A system level comparison between a conventional OFDM and the proposed MSE-OFDM system is presented in this study. Two different realizations of the MSE-OFDM, i.e., CP-reduced and FFT size-reduced MSE-OFDM systems, are investigated for different system requirement. An analysis on the bandwidth efficiency, impact of synchronization errors on the system performance and peak to average power ratio (PAPR) of these systems is presented. Comparisons are made on two different assumptions, i.e., either keeping the symbol size of the MSE-OFDM (i.e., number of the subcarriers) unchanged to increase the bandwidth efficiency, or keeping the bandwidth efficiency unchanged (ratio between CP and useful data transmission time) for system robustness to synchronization errors and a lower peak-to-average power ratio. In the first case for CP-reduced MSE-OFDM, bandwidth efficiency is improved due to a reduced number of CPs inserted between OFDM symbols. For the latter case of FFT size-reduced MSE-OFDM, robustness to synchronization errors is improved considerably due to the smaller number of subcarriers. The proposed system is of particular interest for fixed wireless systems and digital subscriber loops (DSL). Large frame size can be used in these applications, due to the static nature of the channel conditions. Implementation complexity of the MSE-OFDM system is also discussed.