Abstract: Aiming at traditional spreading codes with short period and poor security,a method of spreading codes constructed by means of combination chaotic maps with self-coded was proposed.The method firstly makes a homomorphic uniform mapping to a sequence generated by Logistic chaotic mapping to obtain a high degree of balance pseudo-random sequence,and then repeates iteration with the sub-sequence of different length to obtain the complex symbol sequence of which length increases geometrically by the time of iterations.Finally,it is combined with the self-coded sequence to generate a high quality composite random sequence through the dimensional Henon map.To analyze the effectiveness of the method based on Chaos and self-coded,we compared it by simulation test.The result shows the new spreading code has better correlation and a higher degree of complexity,and obtains a lower spread bit error rate.

Key words: Self-coded,Uniform map,Henon map,Spreading code,Bit error rate