AbstractIn this paper we consider a multi‐sensor detection problem in both additive white Gaussian noise (AWGN) and fading channels with the users using the channel based on a code division multiple access (CDMA) scheme. Several multi‐sensor detectors that have been studied previously do offer good performance; however, these detectors require the knowledge of the signal energies and these have to be estimated. Such an estimation might not be feasible in fading and time‐varying channels. We show how the linear optimal detector can then be simplified to obtain a decorrelating detector which does not require the knowledge of the users' signals. We show that this decorrelating detector performs almost as well as the linear optimal detector in an AWGN channel. We further investigate its performance in single‐path and frequency‐selective slowly fading channels. In a slowly fading channel when there is multi‐user interference, the conventional detector reaches a saturation point beyond which no improvement in performance can be obtained. We show that the performance of the decorrelating detector does not depend on the other users' energies and hence on the other users' fading characteristics. We further show that a decorrelating detector can be used to obtain a Rake type of receiver in frequency‐selective fa