Link Capacity Analysis Research Articles

Modeling Ground-Air Wireless Connectivity: Continuous Connection Probability Analysis

In this paper, we consider three ground-aircraft communication issues, namely, ground-centric connectivity, aircraft-centric connectivity, and link capacity analysis. Particularly, we propose the continuous connection probability over at least τ seconds, termed as τ-connectivity, for the ground-centric link and aircraft-centric link respectively, which are derived in the expression of several key parameters such as the aircraft/ground station density, the aircraft velocity, and the connectable elevation angle threshold. Theoretical tradeoff between ergodic outage capacity and the number of connected aircraft is analyzed for low and high transmit power regimes. The hypotheses in the ground-centric τ-connectivity model are tested, and we observe a good match between the theoretic probability and the real world data-based probability although some real world aircraft statistic characters do not match the ideal assumption perfectly. Next, the aircraft-centric τ-connectivity is analyzed theoretically. Approximate yet practically accurate closed form aircraft-centric connection probabilities are derived and verified with Monte Carlo simulations. Furthermore, considering atmospheric gas and cloud attenuation, we compare the link budget and capacity between the ground-centric ground-to-aircraft link and the ground-to-satellite link under the τ-connectivity and demonstrate the advantage of ground-aircraft communication.

Analysis of resource allocation with macroscopic diversity for uplink OFDMA systems

This paper describes a framework of link capacity analysis for interference mitigation of uplink Orthogonal Frequency Division Multiple Access systems. A Macroscopic Diversity Oriented Resource Allocation (MDORA) is performed via inter-cell coordination based on the location of Mobile Stations (MSs) by exploiting macroscopic diversity in the uplink transmission. In the numerical analysis, the Inter-Cell Interference is derived as a closed form over a multi-cell environment. Subsequent numerical results demonstrate that MDORA offers an efficient inter-cell interference mitigation and a throughput expansion. Moreover, when up-link sectorization is adopted, the MDORA scheme presents a lower inter-cell interference, a reduced outage probability and an improved throughput.

Optimal transmission methodology for QoS provision of multi-hop cellular network

In this paper, we present a framework of link capacity analysis for optimal transmission over uplink MCN (Multi-hop Cellular Network) environments. An overlaid architecture is employed as the network topology, i.e., single-hop transmission over the inner region and multi-hop transmission over the outer region. In particular, we analyzed the gain that accrued from grafting a relay method onto a conventional, SCN (Single-hop Cellular Network) and investigated the conditions for optimal performance through the numerical results. At high-user density, a MCN exhibits a much more reliable transmission than the SCN. For maximal link capacity, optimal region partitioning is approximately accomplished at the normalized cell radius of 0.6 in most of cases for region division. Finally, the link capacity can be improved 1.2---1.8 times better than the SCN when the number of relay hops is 1.6 and the half-duplex mechanism is used. In addition, the proposed MCN scheme demonstrates an effective reduction in transmission power relative to the SCN.

Optimal Carrier Loading Control for the Enhancement of Visual Quality over OFDMA Cellular Networks

A recent dynamic increase in demand for wireless multimedia services has greatly accelerated the research on dynamic channel adaptation of high quality video applications. In this paper, we explore a theoretical approach to cross-layer optimization between multimedia and wireless networks by means of a quality criterion termed ldquovisual throughputrdquo for downlink video transmission using a layered coding algorithm. We obtain the optimal loading ratio of orthogonal frequency division multiple access (OFDMA) subcarriers through an optimization problem balancing the tradeoff relationship between inter-cell interference (ICI) and channel throughput. Through numerical link capacity analysis, we show that the upper bounds of the visual throughput gain at the cell boundary is obtained at about 27%.

Reverse Link Capacity Analysis over Multi-Cell Environments

This paper presents a numerical analysis of reverse link capacity by obtaining a closed form of ICI (InterCell Interference) over OFDM (Orthogonal Frequency Division Multiplexing)-based broadband wireless networks. In the analysis, shadowing factors are taken into account for determining the home BS (Base Station) of each MS (Mobile Station) over multicell environments. Under the consideration, a more accurate analysis of link capacity can be performed compared to Gilhousen's approximation. In the numerical results, it turns out that the actual interference is lower than Gilhousen's approximation with a decrease of around 20% in the interference.

Reverse link capacity analysis of cellular CDMA systems with controlled power disparities and successive interference cancellation

This paper presents a new approach in analyzing the reverse link capacity performance of cellular CDMA systems employing successive interference cancellation (SIC). Due to the controlled power disparity present in such systems previous methods cannot precisely model their inter-cell interference. We first introduce a novel model which allows the accurate analysis and evaluation of the inter-cell interference of cellular CDMA systems with controlled power disparity. Its validity is verified by means of theoretical analysis and computer simulations. Secondly, by using this new inter-cell interference model, a theoretical analysis of the CDMA reverse link capacity is presented. In terms of evaluation results, we focus on the performance improvements SIC offers as compared to single user detection (SUD). Analytical results complemented by equivalent computer simulated performance evaluation results have shown that SIC significantly increases the reverse link capacity of cellular CDMA systems operating in realistic controlled power disparity environments

Reverse link capacity analysis of DS-CDMA systemwithdistributed antennas using selection diversity

The reverse link capacity of a DS-CDMA distributed antenna (DA) system is evaluated. Selection diversity can be used to compensate for the performance degradation due to the sum of interference and noise figures of additional antennas. To evaluate the performance according to the use of diversity, a DA system model is presented and interference analysis shown.

Reverse link capacity analysis of a CDMA cellular system with mixed cell sizes

The demands for mobile communication services are growing rapidly. In heavily populated areas, cell splits are unavoidable to increase the capacity of the cellular system. Cell splitting makes a cellular system have mixed cell sizes. For cell planning, it is necessary to analyze the reverse link capacity of a code-division multiple-access (CDMA) cellular system with mixed cell sizes. In this paper, we propose a method to calculate the reverse link capacity of a CDMA cellular system with mixed cell sizes. When a macro cell is split into three micro cells, as an example, we calculate the reverse link capacities for the three micro cells and the neighboring macro cells. The results show that as the radius of a micro cell decreases, the reverse link capacity of the micro cell increases, while those of the neighboring macro cells decrease.