CDMA systems sequences optimization by simulated annealing

In this paper we consider the problem of asynchronous CDMA (code division multiple access) systems performance optimization by proper selection of spreading sequences (codes). The computational complexity involved induces the search for sub-optimal procedures and the numerical method of “simulated annealing” is applied for this particular problem. Despite the simplicity and arbitrariness of the algorithm, the results are amazing. These results confirm the possibility of performance improvement by sequence selection using the method of simulated annealing. Its advantage, in terms of argument of function Q(.) (assuming “strong signal”, that is, negligible N₀/A².T), is ≈1.0 dB when we compare, for a single user, the worst and best cases