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In this paper we study the performance of a SC-FDMA cellular system when a complete Inter-Cell Interference (ICI) management strategy is implemented. We also introduce a novel sector-and-zone frequency ICI coordination scheme, derived from Fractional Frequency Reuse (FFR), which succeeds on increasing the capacity of an SC-FDMA cellular system. Working together with open-loop Fractional Power Control...
This paper focuses on the Physical Downlink Control Channel (PDCCH) and describes the impact of its realistic constraints on the performance in E-UTRAN LTE TDD system, particularly considering the asymmetric slot resources between downlink and uplink. It is described, when adopting the same PDCCH manager framework in LTE FDD system as in LTE FDD system, the uplink users are not prioritized sufficiently...
This paper presents a novel cross-layer design for joint power and end-to-end rate control optimization in DS-CDMA wireless networks, along with a detailed implementation and evaluation in the network simulator ns-2. Starting with a network utility maximization formulation of the problem, we derive distributed power control, transport rate and queue management schemes that jointly achieve the optimal...
Due to the limited transmission range, data sensed by each sensor has to be forwarded in a multi-hop fashion before being delivered to the sink. The sensors closer to the sink have to forward comparatively more message than sensors at the periphery of the network, the nodes will deplete their batteries earlier. Besides the loss of the sensing capabilities of the nodes close to the sink, a more serious...
This paper introduces a novel architecture for mobile communication networks with guaranteed quality of service. For comparison purposes, performance upperbounds of the whole system are derived subsequently. Their numerical evaluation in real-life simulation scenarios shows that our proposal significantly outperforms the state-of-the-art IEEE 802.11 technology in random topologies with varying traffic...
To investigate how to support user communication sessions in cognitive radio (CR), the radio technology should jointly perform power control, scheduling, and flow routing, which are generated by a multi-hop wireless network. With the adjustments of migrating nodes to neighboring nodes, a bandwidth footprint tree (BFT) is defined in this paper. Based on reducing hot spots approach, the distributed...
In this paper, an energy efficient adaptive modulation scheme is proposed for a wireless cognitive radio ad hoc network, where each node is equipped with cognitive radio and the network is an OFDMA system operating on time slots. In each slot, the users with new traffic demand will sense the spectrum and locate the available subcarrier set. Then they choose subcarriers with favorable channel condition...
When transmitting stochastic traffic flows over wireless networks, there exists an inherent tradeoff between average transmit power and corresponding queuing-delay bound. In this paper, we investigate such a trade-off and show how average power increases as delay-bound requirement becomes stringent. Specifically, we propose the resource allocation schemes to minimize the power consumption subject...
Major design issues in Wireless Ad Hoc Networks is the design of the routing algorithms and the Medium Access Control (MAC) protocols. Spatial TDMA (STDMA) is a ldquoconflict-freerdquo MAC protocol for these networks, thus enabling high spectral utilization. In link-oriented STDMA, the schedule specifies when particular radio links will be activated. Moreover, the use of power control and heuristic...
In UMTS networks, the transmit power for the HSDPA can be a large fraction of the total transmit power of a NodeB. We investigate the impact of three HSDPA transmit power allocation schemes on the performance of a UMTS system with dedicated channel users and HSDPA users. The continuous HSDPA power allocation scheme avoids large steps of the transmit power in order to prevent irregularities in the...
In this paper, we address the issue of transmission power control (TPC) in wireless ad hoc networks. Power control plays an important role in energy saving and network performance enhancement. However, the existing TPC schemes either face the problem of hidden and exposed terminal or have additional hardware requirements. We propose a novel distributed power control protocol, called Receiver Initiated...
The third generation (3G) cellular system supports multimedia traffic with much larger system capacity than its predecessors. The wideband code division multiple access (WCDMA) (J.K.F.O.E. Dahlman et al., 1998)-(T.O.R. Prasad, 1998) is one of the most prominent wireless communication techniques in 3G. To meet the certain quality of service (QoS) (D.W. Negi) requirements for various traffic types is...
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