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Cloud radio access network (C-RAN) is considered to be a promising architecture for the future network due to its competitive advantage in both spectral efficiency and energy efficiency (EE). However, the tremendous increase in the mobile data traffic lead resource allocation in C-RANs to be less flexible and efficient. To solve this problem, an energy efficient resource allocation scheme for uplink...
This paper investigates the energy efficiency (EE) of distributed antenna system (DAS) with continuous-rate adaptive modulation (CAM) under different quality of service requirements, and develops adaptive power allocation (PA) schemes for DAS. Firstly, the EE for DAS with CAM is presented. By maximizing the EE subject to the maximum transmit power, target bit error rate (BER), and minimum spectral...
Heterogeneous cloud radio access networks (H-CRANs), which take a separation of the remote radio units (RRHs) from the baseband units (BBUs), is considered to be a promising architecture for the future network due to its competitive advantages in both spectral efficiency and energy efficiency (EE). The RRH is mainly used to provide high data rate for mobile users (MTs) with high quality of service...
In this paper, we demonstrate the optimal power allocation for QPSK, 16-QAM, and 64-QAM modulation schedules and the role of channel quality indicator (CQI). We used sigmoidal-like utility functions to represent the probability of successful reception of packets at user equipment (UE). CQI as a feedback to the base station (BS) indicates the data rate that a downlink channel can support. With Levenberg-Marquardt...
At present, the user experience provided by smart mobile terminals is limited to the battery capacity. This paper focuses on how to improve the energy efficiency of terminals in OFDMA-based wireless multicast systems with frequency-selective channels. We assume that multicast terminals can switch to sleep mode during the transmission of some OFDM symbols according to their OFDMA frame-level quality...
This paper studies a spectrum sharing cognitive radio (CR) network coexisting with a primary network. In particular, the channel state information (CSI) between the secondary transmitter (STx) and the primary receiver (PRx) is assumed to be outdated due to channel feedback latency. We assume that the secondary user (SU) shall satisfy a given delay quality-of-service (QoS) constraint as well as the...
In this paper, we investigate the power saving issue in cognitive radio (CR) multi-hop relay network. Due to the dynamic property of the wireless channel, the quality of service (QoS) guarantee for multi-hop transmission is quite challenging. To deal with these problems, automatic repeat-request (ARQ) protocol in an end-to-end manner is incorporated. For multi-hop transmission evaluation purpose,...
In this paper, we study the cross-layer resource allocation for the secondary users (SUs) supporting heterogeneous services in interference-limited spectrum sharing system. Two classes of SUs are considered: delay-tolerant SUs (DT-SUs) and delay- sensitive SUs (DS-SUs). With the queue theory, the delay requirements of DS-SUs are transformed into constant rate requirements. Unlike most previous works,...
In this paper, a radio resource allocation and scheduling algorithm for multi-user MISO-OFDMA systems with downlink zero-forcing beamforming is proposed to efficiently support the diverse quality of service (QoS) requirements of heterogeneous services. According to the channel state information (CSI) and the queue state information (QSI), the proposed algorithm dynamically assigns subcarriers and...
In this paper, three centralized packet scheduling schemes with fairness-oriented feature are proposed for OFDMA multihop relaying networks, namely Greedy polling with novel starvation restrained (SR-GP), enhanced proportional fairness with SR (SR-EPF) and novel subcarrier pairing with hop balance (HB-SP) scheduling algorithms. SR-GP can bring better fairness than traditional throughput-oriented algorithms...
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