A chaos-based CDMA scheme with a chaos-based encryption algorithm

An encryption algorithm based on a discretized chaotic map controlled by a Δ-modulated feedback is applied to a direct sequence code-division-multiple-access (DS-CDMA) scheme, which improves security at the cost of lowering the performance of bit error rate (BER). However, numerical simulations show that the DS-CDMA scheme still has a satisfactory performance by means of the spreading sequences generated by a continuous chaotic system. These spreading sequences are chosen from the local maximums of the output of the continuous chaotic system. This scheme is also robust against the channel noise.