TURBO CODING ON OFDM TRANSMISSION TO IMPROVE BER

A model of Turbo code based on OFDM (Orthogonal Frequency Division Multiplexing) is proposed in this paper. Orthogonal Frequency Division Multiplexing (OFDM) has become a popular modulation method in high speed wireless communications. By partitioning a wideband fading channel into flat narrowband channels, OFDM is able to mitigate the detrimental effects of multipath fading using a simple one-tap equalizer. There is a growing need to quickly transmit information wirelessly and accurately. OFDM is a suitable candidate for high data rate transmission with forward error correction (FEC) methods over wireless channels. In this project the system throughput of a working OFDM system has been enhanced by adding turbo coding. The use of turbo coding and power allocation in OFDM is useful to the desired performance at higher data rates. Simulation is to be done over additive white Gaussian noise (AWGN) and impulsive noise (which is produced in broadband transmission) channels. The wideband system has 48 data sub-channels; each is individually modulated according to channel state information acquired during the previous burst. This project is to increase the system throughput while maintaining system performance under a desired bit error rate (BER). To improve, the performance of the uncoded OFDM signals by convolution coding.

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