Multiple access schemes over multipath fading channels

We compare the performance of different accessing schemes for communication over an additive white Gaussian noise multiple access channel with multipath fading. We assume that only the receiver can track the channel variations. We investigate time division, frequency division and code division multiple access schemes and consider the Shannon capacity as well as the probability of outage. Although orthogonal code division multiple access has the same total capacity with frequency and time division, it has better probability of outage. We also provide an extension of our comparison to a CDMA system employing non-orthogonal codes and multiuser detection.