Cellular CDMA with downlink single-channel interference-mitigating detection: a semi-analytic capacity evaluation

Focuses on (low complexity) adaptive minimum mean-square error (MMSE) single-channel detection in the mobile user terminal (UT) of a code-division multiple access (CDMA) cellular network. With respect to the conventional (single-channel) correlation receiver (CR), such detector leads to a significant improvement in the delivered quality of service (QoS), through joint interference mitigation and channel equalization. As is peculiar to CDMA, this QoS improvement can be turned into a capacity increase in terms of accommodated users/cell. In this contribution, we compute network, capacity and bit-error rate (BER) performance both for the CR and for the MMSE detector on the Gaussian as well as on the time-varying multipath channel, with perfect and imperfect downlink power control. It turns out that the MMSE detector leads to a nonnegligible downlink capacity enhancement with respect to the CR, and is also less sensitive than CR to power-control imperfections.