Novel optimum signature sequences in MC-CDMA system with frequency selective fading channel

We present the novel optimum signature sequence sets for improving the performance of the downlink MC-CDMA system over a frequency selective fading channel. The proposed optimum signature sequences are constructed by using the iterative technique. The set of optimum signature sequences minimizes the total squared correlations (TSC). They form the set of orthogonal signature sequences when the number of users are less than or equal to processing gain and the set which satisfy the TSC bound equality, otherwise. Our proposed optimum signature sequence outperforms other known families of signature sequences such as the Hadamard Walsh code. The simulation results confirm the advantage of our proposed signature sequences.