Abstract

In this contribution, the performance of a downlink CDMA system with orthogonal spreading and multi-cell interference is analyzed. A useful framework is provided in order to determine the optimal base station coverage for wireless frequency selective channels with dense networks where each user is equipped with a matched filter. Using asymptotic arguments, explicit expressions of the spectral e#ciency are obtained and provide a simple expression of the network capacity based only on a few meaningful parameters. Contrarily to a common misconception which asserts that to increase capacity in a CDMA network, one has to increase the number of cells, we show that, depending on the path loss, the size of the network and the fading channel statistics, the code orthogonal gain (due to the synchronization of all the users at the base station) can compensate and even compete in many cases with the drawbacks due to inter-cell interference. The results are especially realistic and useful for the design of dense networks.

Citations