Differential Space-Time Block Code Modulation for DS-CDMA Systems

Differential Space-Time Block Code Modulation for DS-CDMA Systems

A differential space-time block code (DSTBC) modulation scheme is used to improve the performance of DS-CDMA systems in fast time-dispersive fading channels. The resulting scheme is referred to as the differential space-time block code modulation for DS-CDMA (DSTBC-CDMA) systems. The new modulation and demodulation schemes are especially studied for the down-link transmission of DS-CDMA systems...

Differential space-time modulation schemes for DS-CDMA systems

Differential space-time modulation (DSTM) schemes were recently proposed to fully exploit the receive and transmit antenna diversities without the need for channel state information. DSTM is attractive in fast flat fading channels since accurate channel estimation is difficult to achieve. In this paper, we propose a new modulation scheme to improve the performance of DS-CDMA systems in fast tim...

Space Time Coding for DS-CDMA systems

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...

A space-time channel estimator and single-user receiver for code-reuse DS-CDMA systems

In this paper, a blind asynchronous single-user code-reuse direct sequence code division multiple access (CDMA) array receiver is proposed for the uplink. By assigning each short PN-code more than once, code reuse allows the number of active users to be increased beyond the spreading gain. The proposed receiver is based on a blind single-code multipath joint space–time channel estimation techni...