Subchannel Power Control in the DT-OFDM System for Satellite Communications in Ka Band

In order to meet Ka-band hostile propagation environment and satisfy the need of high quality multimedia communication, a subchannel power controlled differential Turbo coded OFDM (DT-OFDM) system for satellite communications in Ka band was presented. The proposed DT-OFDM scheme combines subchannel power control techniques, Turbo coding, orthogonal frequency division multiplexing (OFDM) modulation and differential detection and takes advantages of these techniques. The system model for the scheme has been found, based on the Ka band channel model. The performance of the system has been analyzed using Microwave Office 2003/Visual System Simulator2003. Simulation results show that the proposed TD-OFDM system gives about 3.1, 3.6 and 4dB gains in SNR for the required BER equal to 10^-1 ,10^-2 and 10^-3 respectively, compared to conventional coded OFDM (COFDM) system.