A New Approach of Channel Modeling in HAPS Based Networks and Their System Performance Analysis

Abstract

This paper concerns channel modeling for High Altitude Platform Systems (HAPS) and the performance evaluation of Hybrid_ARQ in the WiMAX network provided by HAPS. The stratospheric platform or HAPS is currently a new proposal for WiMAX technology. Firstly we study the HAPS channel behavior as a Finite State Markov Channel (FSMC). In this way, the range of magnitude of the fading channel gain is partitioned into a finite number of states; then based on level crossing rates, the state transition probabilities are derived. The validity of the proposed model is evaluated by theoretical and link level simulation results. Next, we use the derived state transition probabilities as channel model parameters in OPNET simulator for HAPS-WiMAX to calculate HARQ system level measures. The paper compares the performance obtained using two different models in fading effects, i.e. AWGN and our HAPS channel model. In addition, the influence of parameters is analyzed through comparison between our model and the Stanford University Interim (SUI) channel models, in terms of the Bit Error Rate (BER).