In order to judge the goodness of zero correlation zone sequence sets, a new concept, called ZCZ characteristic, is proposed. Then by defining a sequence operation, i.e. correlation product, and establishing its basic properties, a new approach to construct sets of sequences with a large zero correlation zone is presented.

In the present paper, we evaluate the inter-cell interference of AS-CDMA systems. First, the cross-correlation property of AS-CDMA systems is examined by theoretical study in order to clarify the fundamental feature of the inter-cell interference. The result shows that the influence of one interference terminal in each adjacent cell is dominant regardless of whether approximate synchronization is maintained. Next, the ratio of interference signal power and desired signal power is evaluated by computer simulation. The simulation result shows that total interference power does not increase even when approximate synchronization is not maintained.