Author's Name:	Pendli Pradeep & Mr.S.P.V Subba Rao
Subject Area:	Science and Engineering
Subject	Engineering
Section	Research Paper

Cognitive Radio, OFDM, Spectrum Sensing.

Spectrum sensing is one of the core technologies of Cognitive Radio (CR) systems which provide a viable solution to the problem of sparsity of wireless spectrum. Nowadays, OFDM techniques are adopted by many existing or progressing wireless communication standards. Accuracy and speed of estimation are the key indicators to select the appropriate spectrum sensing technique. Multi-carrier techniques such as OFDM are widely adopted in the physical layer of nowadays radio communication and broadcasting systems. Therefore in cognitive radio, a robust spectrum sensing techniques for such signals is highly desired. Cyclic Prefix (CP), Time-Domain Symbol Cross-correlation based spectrum sensing (TDSC) methods are used for sensing the spectrum. TDSC method have advantages in sensing accuracy and robustness compared to CP. CTDSC method using 64DAPSK modulation is used and compared with CTDSC QAM and it results 1dB SNR improved over QAM.