Subspace-based noncoherent detection for CDMA channels

This paper presents a noncoherent subspace detection approach based on oblique projections for DS-CDMA systems, which performs complete rejection of interfering signals. The synchronous and asynchronous subspace detectors are introduced and examined. The transmission delays in asynchronous CDMA channels are not known to the receiver in practice. The effect of code acquisition errors on the performance of the noncoherent subspace detector is investigated. A robust noncoherent subspace detector in the presence of acquisition errors is presented, which shows reliable performance even under worse condition than the code acquisition algorithms may support.