Packet-Level Channel Model for Wireless OFDM Systems

In this paper, we develop a novel packet-level channel model for orthogonal frequency-division multiplexing (OFDM) systems over frequency-selective Nakagami-m fading channel. Since the subcarriers are correlated, the Level Cross Rate (LCR) in frequency response is introduced and derived. A complete model including finite state Markov chains in both the time domain and the frequency domain is proposed for the multi- carrier system, which models the received signal to noise ratio (SNR) of each subcarrier and further presents the packet error behavior of the OFDM system. This model is useful for upper layer protocol design and analysis over OFDM systems, and it speeds up significantly the simulation for OFDM networks over fading channels. The model is validated by simulations, which confirm that the statistical properties of the frequency-selective fading channel have been maintained in our model.