Joint user selection algorithm and fully digital Geometric Mean Decomposition (GMD)-based precoding scheme is considered in this paper for single Radio Frequency (RF) Space Modulation Techniques (SMTs), namely, Spatial Modulation (SM) and Space Shift Keying (SSK) schemes. The objective is to jointly perform the Frobenius norm-based user selection algorithm and design GMD-based precoded SMTs with single-RF chain in order to reduce the cost and the power consumption in Multiple Input Multiple Output (MIMO) systems, and to avoid the complicated bit-allocation problem of Singular Value Decomposition (SVD)-based precoding technique. Based on these schemes, the GMD-based precoding transmission carried out in the context of a single-user SMTs can readily be extended to the Multi-user (MU) case. Simulation results demonstrate that single-RF SMTs with GMD-based precoding scheme is capable of outperforming SMTs with SVD-based precoding technique. Meanwhile, MU-SMTs with GMD-based precoding scheme provide significant performance gains over the conventional SM- and SSK-MIMO counterparts and single-user SMTs with GMD-based precoding algorithm, which increase the energy efficiency and the reachability using these schemes. Furthermore, better error performance in MU-SMTs with fully digital GMD-based precoding technique is obtained by selecting any number of users. Therefore, MU-SMTs with GMD-based precoding scheme can be effectively used in various 5G wireless networks.
Taissir Y. Elganimi, Feras F. Alfitouri(1-2021)

Abstract In order to ensure the promise of anytime-anywhere communication to the customers, Mobile operators must be able to support a large number of users over a large coverage area. So Coverage and Capacity are important issues in the planning process for Third Generation (3G) mobile networks. The planning process aims to allow the maximum number of users sending and receiving adequate signal strength in a cell. In Code division multiple access (CDMA), the Coverage and capacity are not independent of each other as in GSM, it is interference-limited system, meaning that if the traffic increases, the serving cell radius decreases, hence the term cell breathing occurs. This work studies the capacity and coverage of a macrocell CDMA network. The cell breathing effect is studied and a new criteria to link Capacity and Coverage is developed, it is named by Capacity-Coverage Product; CCP. Different designations of CCP formula are given. The influencing of various system parameters on this CCP are studied. Knowing this CCP, the capacity and coverage become straight to estimate. The user distribution is very important issue. Most of previous studies treat user distribution as uniform. This thesis considers the case of non uniform user distributions where a more realistic distribution is chosen. A new interference distribution factor is initiated. The impact of this factor on the capacity and coverage is studied. Existing of Hotspot regions of traffic will cause coverage shrinkage. Installation of hotspot microcells BS inside existing macrocell BS is one possible solution to such situations. In this work a microcell is introduced within the macrocell and a new system parameters are obtained such that the coverage and performance are maintained while the capacity is increased.
محمد عبدالرزاق العالم (2007)

In this paper, we present an analytical traffic model for the Universal Mobile Telecommunication Systems (UMTS). In 3G networks we have dynamic capacity that depends on the interference levels in the covered area and the number of active users. This implies that the distance of the mobile user from the base station is also an important factor because of the signal fading. The first part of this paper is an algorithm written in c++ programming language that distributes users in different zones assuming that the cell area is virtually divided into Z zones depending on the number of users. The last part of this paper we build a mathematical model of a 3G cell using the above assumption , and to prove, that the product form holds in the case of two cells with uniform and non uniform traffic. By this result more complicated networks can be analyzed, to calculate the performance measures of the network.
WAEL S. ABUGHRES, MIKE E. WOODWARD(6-2006)