Performance of multicell CDMA with power control error

It has been found that power control is a critical factor in the performance of a CDMA mobile system. The error probability of a multicell mobile CDMA system operating with imperfect power control over a frequency selective multipath fading channel is derived. A simple asymptotic expression for the error probability is found when the signal to interference and Gaussian noise ratio is large. In addition, an upper bound on the error probability is obtained by using Jensen's inequality for a frequency nonselective fading channel. It is found analytically that the error probability increases exponentially with the power control error, and linearly with other factors such as the number of users or the processing gain. It is also found that diversity techniques increase the error probability due to the power control error, because the power control error is identical for each diversity channel.