Interference Reduction in MB-OFDM Ultra Wideband Systems using Block Turbo Code

OFDM can provide large data rates, many research centers in the world have specialized teams working in the optimization of OFDM for countless applications. Coded-OFDM is robust to radio fading channels impairments. Since the UWB spectrum has the unlicensed nature all wireless devices sharing the spectrum must coexist. According to MBOA, multiband OFDM is capable of complying with local regulations by dynamically turning off certain tones or channels in software, which speaks to their favor.To suppress the side-band interferences in Ultra wideband(UWB)caused by multiband orthogonal frequency division multiplexing (MB-OFDM), a soft-spectrum adaptation based Detect and Avoid mechanism is proposed. Detection technique is based on power spectrum density estimation and Avoidance mechanism is based on subcarrier nullifying using windowing. A type of block Turbo code modulation scheme is proposed. In the modulation scheme, the sideband interferences are attenuated quickly. Simulation result of softspectrum based detect and avoid technique is shown along with SNR performance comparison between coded and uncoded OFDM.