Performance evaluation of adaptive bit loading for OFDM with channel estimation using 2 x 1-D wiener filter

Abstract

Channel State Information is crucail in applying adaptive bit loading to OFDM system. The number of bits allocated to each subcarrier is determined by the quantity of the channel state estimate and the noise variance estimate. In this paper performance of several adaptive bit loading algorithms for OFDM transmission over mobile fading channels are studied and compared. The novelty of this paper is the use of 2 x 1D Wiener filter channel estimation in evaluating the performance of several bit loading algorithms. The use of SNR grid in SImple Blockwise Loadgin Algorithm (SBLA) is extended. The performance of grouping of the OFDM subcarriers based on the channel gain order and subcarrierwise bit loading using the SNR grid are also evaluated.