Incremental gradient algorithm for multiuser detection in multi-carrier DS-CDMA system under modulation schemes

Nonlinear Multiuser Receiver for Optimized Chaos-Based DS-CDMA Systems

Chaos based communications have drawn increasing attention over the past years. Chaotic signals are derived from non-linear dynamic systems. They are aperiodic, broadband and deterministic signals that appear random in the time domain. Because of these properties, chaotic signals have been proposed to generate spreading sequences for wide-band secure communication recently. Like conventional DS...

Multiuser Detection in DS-CDMA

Multiuser Detection in DS-CDMA

The theory of Multiuser Detection (MUD) for DS-CDMA is studied. A brief description of optimal MUD is given and some low complexity sub optimal implementations are described. This is followed by a short note on Blind Multiuser detection. Conclusions are drawn from theoretical and simulation results. Towards the end, a new low complexity scheme for MUD in DS-CMDA is proposed. Simulation results ...

Stochastic conjugate gradient based multi-user constant modulus algorithm for use in multiuser DS-CDMA environment

A Stochastic Conjugate Gradient Algorithms (SCGA) is proposed for the solving nonlinear optimization problem assodated with the multi-nser constant modulus algorithm (CC-CMA) for DSCDMA receivers in a multi-user environment. The algorithm referred to as the stochastic conjngate gradient CC-CMA (SCGCC-CMA). Simulatious show that the SCGCCCMA algorithm preserves the fast convergence rate of the b...

Subspace multiuser detection for multicarrier DS-CDMA

A subspace-based linear minimum mean-squared error (MMSE) multiuser detection scheme is proposed for a multicarrier direct-sequence code-division multiple-access (MC-DSCDMA) system. Typically, a MC-DS-CDMA system employs a band-limited chip waveform. The band-limited nature of the chip waveform causes problem in applying standard subspace techniques because no nonnull noise subspace can be form...