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Energy-efficiency, one of the major design goals in wireless cellular networks, has received much attention lately, due to increased awareness of environmental issues and economic issues for network operators. In this paper, we develop a theoretical framework for BS energy saving that encompasses dynamic BS operation and the related problem of user(More)
—In this paper, we investigate dynamic base station (BS) switching to reduce energy consumption in wireless cellular networks. Specifically, we formulate a general energy minimization problem pertaining to BS switching that is known to be a difficult combinatorial problem and requires high computational complexity as well as large signaling overhead. We(More)
Next-generation cellular networks will provide higher cell capacity by adopting advanced physical layer techniques and broader bandwidth. Even in such networks, boundary users would suffer from low throughput due to severe inter-cell interference and unbalanced user distributions among cells, unless additional schemes to mitigate this problem are employed.(More)
—Due to the increasing demand of capacity in wireless cellular networks, the small cells such as pico and femto cells are becoming more popular to enjoy a spatial reuse gain, and thus cells with different sizes are expected to coexist in a complex manner. In such a heterogeneous environment, the role of interference management (IM) becomes of more(More)
—This paper develops an energy-aware hierarchical cell configuration framework that encompasses both deployment and operation in downlink cellular networks. Specifically, we first formulate a general problem pertaining to total energy consumption minimization while satisfying the requirement of area spectral efficiency (ASE), and then decompose it into(More)
—This paper considers a component-level deceleration technique in BS operation, called speed-scaling, that is more conservative than entirely shutting down BSs, yet can conserve dynamic power effectively during periods of low load while ensuring full coverage at all times. By formulating a total cost minimization that allows for a flexible tradeoff between(More)
—This paper investigates power allocation algorithms for OFDM-based cognitive radio systems, where the intra-system channel state information (CSI) of the secondary user (SU) is perfectly known. However, due to loose cooperation between the SU and the primary user (PU), the inter-system CSI is only partially available to the SU transmitter. Two types of PUs(More)
—In order to overcome low performance of conventional static interference management algorithms and high complexity of existing dynamic interference management algorithms, this paper proposes an efficient, low-complex and fully distributed power control and user scheduling algorithm in downlink multi-carrier multi-cell wireless networks. We decompose the(More)
Feedback reduction in multiuser OFDM systems becomes an important issue due to the excessive amount of feedback required to run opportunistic scheduling, especially when the number of users and carriers in the system increases. In this paper we propose a novel feedback reduction scheme for efficient downlink scheduling. In the proposed scheme, each user(More)