Smart channel-assignment algorithm for SDMA systems

Abstract

In order to exploit the potentialities of space-division multiple access in mobile cellular systems, the conventional radio resource management functions must be revised-especially the channel-assignment algorithms. In this paper, an algorithm designed to this purpose is presented and analyzed in reference scenarios and under various traffic load conditions, showing that a significant reduction of the intracell handover rate can be achieved. The proposed algorithm is not based solely on the current angular separation between mobiles, but also takes into account their potential future trajectory, predicted by means on the knowledge of the topography of the analyzed service area.Index Terms-Channel-assignment algorithm, intracell handover, SDMA.

Traffic Models and Blocking Probabilities for Two-Fold and Three-Fold SDMA Communication Systems

“…Sophisticated approaches [11] are not only based on the angular separation between mobiles but also take mobile speed and geometric information into account to predict future trajectory. We adopt two common spatial separation check criteria: (i) angle separation and (ii) minimum interference energy.…”

An Overview of SDMA in Communications Systems

“…This is, if the signal quality of the users that share the same channel decreases, one or more users must be transferred to other channel or blocked if there are not available channels. SDMA needs some particular requirements and criteria for the radio resource management as can be shown in [9,10].…”

“…), it is clear that implementation of the system requires a complex network due to the digital signal processing algorithm selected. In general, the transmission and reception spatially selective of the signals, gives an important increase of capacity, coverage and quality in a communication system [8][9][10]. In this context, different authors show that a system using SDMA has better performance (an increase of capacity and signal quality) than a system without SDMA [2,9,10].…”

Capacity enhancement in SDMA scheme with orthogonal code

“…PERFORMANCE OF DSC SCHEME Now, we use the same orientation of 17 mobile users same as figure 4 to evaluate the C/I performance using DSC signature scheme. Let the desired user location as 90' of the smart antenna array's axis.…”

“…SDMA allows the simultaneous use of any conventional channel (frequency, time slot, or code) by multiple users of the same cell by exploiting the users angular separation relative to the BS. This increases the spectral efficiency and, hence, the capacity of the system [3], [4]. This objective can be achieved via three basic approaches namely main beam steering, multipath suppression, and interfering nulling [SI.…”