Error rate of a multicarrier CDMA system with imperfect channel estimates

Bit error rate is evaluated for a multicarrier CDMA system with channel estimation errors. We consider a multicarrier CDMA system with pilot and data channels. The signal experiences independent flat Rayleigh fading on each subcarrier. Simple integrators produce the channel estimates which are used to maximal-ratio-combine the data from all the subcarriers, Keeping the total transmitted energy fixed, as the number of subcarriers increases, the weaker signal in each subcarrier makes channel estimation more difficult and results in larger errors in the combiner weights. We quantify how errors in channel estimation affect a multicarrier CDMA system as the system becomes more wideband. We show that there is a tradeoff between diversity order and SNR available for channel estimation