Effect Of Power Control Error Research Articles

A novel MAC protocol for IDMA‐based multi‐beam satellite communication systems

SUMMARYConsidering the limitations of satellite communication systems and advantages of new emerging interleave‐division multiple access (IDMA) technology, IDMA is introduced into the satellite systems, providing a new solution for multiple access techniques of satellite systems. To further validate the IDMA into satellite systems, a novel medium access control (MAC) scheme is proposed. In the random access channel, the interleave‐division slotted ALOHA method is adopted to alleviate the collision of access requests. Furthermore, a novel minimum power allocation scheme based on signal‐to‐interference‐plus‐noise ratio (SINR) evolution is proposed to maximize the capacity of such an interference‐sensitive system. By virtue of SINR evolution, our proposed scheme can accurately estimate multi‐user detection efficiency with low computational cost and further reduce the transmitted power, illustrating the high power efficiency of IDMA. To further enhance the performance of the MAC protocol, an effective call admission control scheme considering the effect of power control error is designed and combined into our MAC protocol. Analysis and simulation results show that, by taking full advantage of the chip‐by‐chip multi‐user detection technique, the proposed IDMA MAC protocol achieves high throughput and low average packet delay simultaneously, with low onboard processing complexity in the multi‐beam satellite communication systems. Copyright © 2013 John Wiley & Sons, Ltd.

Web traffic capacity of multi-beam GEO and MEO mobile satellite systems

An investigation into the downlink web traffic capacity of W-CDMA land mobile satellite communication systems for Geostationary (GEO) and Medium Earth Orbit (MEO) constellations is presented. It is shown that the effect of power control errors on the web traffic capacity severely degrades the performance of mobile satellite systems. It is also shown that the use of the proposed macrodiversity system is to mitigate the effect of power control errors, and consequently increases the web traffic capacity of multi-beam GEO and MEO mobile satellite systems.

Analysis of power control and its imperfections in CDMA cellular systems

We develop a general model to study the forward-link capacity of a code-division multiple access (CDMA) cellular system with power control. Using this model, two forward-link power control schemes (nth-power-of-distance power control scheme and optimum power control scheme) are examined. The increase in capacity by using power control has been studied. The capacities of the forward link are also compared with those of the reverse link with perfect power control. In the case of imperfect power control, an analytical model is presented to study the effect of power control error in a CDMA cellular system. The effect of the dynamic range of transmission, moreover, has also been analyzed.