Zheng and Barton developed a convenient signaling scheme (orthogonal on-off BPSK (OBPSK)) with a simple one-shot linear decorrelating detector (LDD) for near–far resistant detection in asynchronous DS/CDMA systems. This paper studies the performance of the OBPSK LDD system over a frequency-nonselective and slowly fading channel. Three types of channel model are considered, namely Rayleigh fadin...

| This paper introduces a new multiuser detection algorithm based on a gradient guided search that can achieve near-optimum performance while its implementation complexity is linear in the number of users. The new algorithm attempts to perform jointly optimum multiuser detection by updating one user's bit decision each iteration in the best possible way. When a decorrelating multiuser detector ...

|We consider a dual rate synchronous DS/CDMA system in which the length of each signature sequence is inversely proportional to the corresponding data rate. Two types of decorrelators that employ the diierence in processing gains have been proposed: a high-rate decorrelator (HRD) matched to the data rate of the high-rate users, and a low-rate decorrelator (LRD) matched to the data rate of the l...

In this study 1 we derive the general form of an optimal one-shot multiuser detector given any density for the users' amplitudes. It is shown that well-known multiuser receivers such as the maximum likelihood detector, the decorrelating detector and even the MMSE detector are special cases of the above receiver, each optimal given a particular assumption about the density of the users' amplitud...

The use of code division multiple access (CDMA) makes third-generation wireless systems interference limited rather than noise limited. The research for new methods to reduce interference and increase efficiency led us to formulate a signaling method where fast impulsive silence states are mapped on zero-energy symbols. The theoretical formulation of the optimum receiver is reported and the asy...

In this paper, we consider the quasi-maximumlikelihood (quasi-ML) detectors of the reverse link system that uses antenna arrays in asynchronous channels when the channel vector is time-invariant and time-varying. A channel vector estimation method based on eigendecomposition for time-invariant channels and its adaptive version suitable for the time-varying channels are also proposed. It is show...

We consider a stochastically forced nonlinear oscillator driven by stationary Gaussian noise that has an algebraically decaying covariance function. It is well known such processes can be renormalized to converge fractional Brownian motion, process memory. In contrast, we show the limit of this converges diffusion standard (not fractional) and thus retains no memory in scaling limit. The proof ...