Paper Title
Bit Error Rate (BER) Performance Analysis Of Carrier Interferometry Codes In A Cognitive Radio (Cr) Environment

Multi Carrier Code Division Multiple Access (MC-CDMA) and Orthogonal Frequency Division Multiplexing (OFDM) are the two most efficient multiple access techniques in a multiuser environment. However, Multiuser Interference (MUI) and Co-Space Interference (CSI) are the two major challenges when multiple antennas are deployed at the transmitter and receiver ends. Moreover, in a Cognitive Radio (CR) system, the secondary users that use MC-CDMA technique must deactivate the sub carriers used by the primary users resulting in the loss of orthogonality of the conventional spreading codes such as Hadamard Walsh codes. To solve the resultant non-orthogonality problem, the Complex Carrier Interferometry (CI) codes are utilized that exist for any length. The method of Total Interference Cancellation (TIC) in combination with Singular Value Decomposition (SVD) helps to combat the problem of MUI and CSI. However, the performance of these CI codes deteriorates due to small singular values of the channel matrix. To enhance the performance of CI-TIC, Minimum Output Energy (MOE) error criterion is employed to reduce the noise.