In CDMA (Code - Division Multiple - Access) systems multi - user accessing of a channel is possible. Under the assumptions of Optimum multi - user and decorrelating detector in CDMA systems. By using signals with zero and / or identical cross correlations, a simple and expandable decorrelating detector with optimum efficiency which can be easily implemented are proposed. Constructing these sign...

In this paper, a new multiuser detector combining multicarrier and decorrelating detection schemes is proposed and analyzed in a frequency selective Rayleigh fading channel. The bit error probability is derived and compared with that of the conventional decorrelating detector. From the numerical results, it is shown that the proposed detector achieves better BER performance and lower computatio...

| We investigate multiuser signal detection with a base-station antenna array for synchronous CDMA Rayleigh fading uplink channels. We have developed a discrete-time model that enables the formulation of a spatial-temporal decorrelating detector using the maximum-likelihood criterion. The detector is shown to be near-far resistant. We further propose to implement the spatial-temporal decorrelat...

In this paper, multiuser detectors for a synchronous code division multiple access (CDMA) channel are adopted for detecting a spread spectrum signal in the presence of a digitally modulated narrowband interference (NBI). The bit error probability of a decorrelating detector is independent of the ratio of the power of a digitally modulated NBI signal to that of a spread spectrum signal but not i...

Abstract We propose an extended one-shot decorrelating detector (EOS-DD) for asynchronous DS/CDMA systems in frequency selective fading environments. The EOS-DD extends a processing window to several symbol duration. The received signal over an extended window is utilized for the decorrelator in the EOS-DD. The effects of the window size on BER performance are investigated by numerical analysis...

We investigate a new robust multiuser signal detector for asynchronous code-division multiple-access uplink channels under delay mismatch. We first formulate a robust decorrelating detector by dividing each user into two virtual users with rectangular chip pulse shapes. To increase the system capacity, a multistage version of the robust decorrelating detector is derived, which can achieve capac...

In order to reduce the computational complexity of the decorrelating detector in multipath fading asynchronous CDMA channels, we consider implementing it by linear multistage successive interference cancellation (MSIC), derived from the Gauss-Seidel iterations. In this paper we propose a multipath decorrelating SIC (MD-SIC) with differentially coherent equal gain combining (DEGC). The convergen...

The noncoherent demodulation of differentially phase-shift keyed signals transmitted simultaneously via a synchronous CDMA channel is studied under the assumption of white Gaussian background noise. A class of noncoherent linear detectors is defined with the objective of obtaining the optimal one. The performance criterion considered is near-far resistance, which denotes worst-case multiuser as...

We investigate an improved multiuser detector for asynchronous CDMA uplink channels when there exist timing delay estimation errors. We first formulate a robust decorrelating detector with a capacity limit of 50%. To increase the system capacity, we further propose a robust successive interference cancellation (SIC) implementation. The proposed robust SIC detector adds only a residual error est...

The decorrelating detector is known to eliminate multiaccess interference when the signature sequences of the users are linearly independent, at the cost of enhancing the Gaussian receiver noise. In this paper, we present a blind adaptive decorrelating detector which is based on the observation of readily available statistics. The algorithm recursively updates the filter coefficients of a desir...