Iterative construction of sequences with low crosscorrelation values

The possibility of generating sequences with low cross-correlation values by using an iterative technique is investigated. They can be used in DS-CDMA (direct-sequence code division multiple access) systems, with the spreading and the despreading sequences being different. It can be shown that, especially for small widths of the interval considered or small numbers of sequences, large improvements of the criteria considered can be achieved. Moreover, in contrast to other well-known construction methods for code families, even and odd correlation properties can be optimized. A disadvantage of this procedure is the increased sensitivity against additive white noise. The application of different spreading and despreading sequences will be useful when the cross-correlation interferences are the main source of disturbance. Compared with other crosscorrelation cancellation techniques, this method has a smaller suppression of disturbance but it needs no additional signal processing