This paper deals with channel estimation, and detection in ultra wide band (UWB) bi-phase impulse modulated systems. We address the single user and the multiuser scenario assuming a direct sequence spreading code division multiple access (DS-CDMA) scheme. The channel estimation and detection approach is single user based, and operates in the frequency domain. In the presence of multiple access ...

Recently, a novel scheme for iterative multiuser detection and turbo decoding was proposed by Damnjanovic and Vojcic. In this scheme, multiuser detection and single-user turbo decoding are tightly coupled to maximize the overall gain. The extrinsic probabilities for the coded bits of the interfering users, obtained after each turbo decoding iteration, are used as a priori probabilities in the f...

| In this paper, we develop an iterative multiuser receiver for decoding Turbo coded synchronous CDMA signals in both Gaussian and non-Gaussian noise. A soft-input soft-output non-linear multiuser detector is combined with a set of single user channel decoders in an iterative detec-tion/decoding structure. The non-linear multiuser detector utilizes the prior probabilities of each user's bits to...

Multiuser detection is an important technology in wireless CDMA systems for improving both data rate as well as user capacity. However, the computational complexity of multiuser detection prevents the widespread use of this technique. Most of the CDMA systems today and in the near future will continue to use the conventional matched filter with its comparatively low user capacity and a slow dat...

Multiuser detection by iterated soft{decision interference cancellation is known to achieve almost single user performance in low and moderate interference scenarios. In this paper, it is shown how this detection scheme can be further improved by adaptive calculation of the soft{decision rule. This enables a signiicantly higher number of active users signaling within the same bandwidth to be de...

-The Hopfield neural network (HNN) is introduced in the paper and is proposed as an effective multiuser detection in direct sequence-ultra-wideband (DS-UWB) systems. It can approximate to maximum likelihood (ML) detector by mathematical analysis. According to the HNN-based technique, the computer simulation results show that they have good performances and much lower computational complexity in...

This paper illustrates the use of “averaging” to improve the convergence rate of adaptive sign regressor and sign error multiuser detectors. The ingenious concept of averaging was invented by Polyak in 1990 – this paper analyses the performance of averaging in the sign error and sign regressor adaptive blind multiuser detection algorithms in DS/CDMA Systems.