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In this paper, the problem of fairly balancing the radar and communication performance in a dual communication and radar system is studied. To gain insight into the problem, a simple model of such a system using OFDM-style waveforms with SNR as the radar's objective and throughput as the communication's objective is explored. As a criteria for balancing the performance of both objectives, α fairness...
In this paper, we study the throughput of compressive random access for machine type communications (MTC) and compare it with that of multi-channel ALOHA. In compressive random access, the sparsity of active devices is exploited to use compressive sensing (CS) based low-complexity multiuser detection (MUD) when non-orthogonal spreading codes are used to support a number of devices. For tractable analysis,...
The throughput of a conventional rate-compatible code based hybrid automatic repeat request (HARQ) protocol is lower-bounded by the rate of the mother code used. The mother code rate along with the highest puncture rate determine the operation range of the protocol in terms of the average received signal-to-noise ratio (SNR). In this paper, we propose a new HARQ protocol based on rate-compatible punctured...
In this paper, we investigate a user-centric Coordinated Multiple Point (CoMP) transmission scheme to improve Energy Efficiency (EE) in dense Heterogeneous Network (HetNet), which takes advantage of both Dynamic Point Reduced Power (DPRP) and Joint Transmission (JT). DPRP with a user voting method rather than Dynamic Point Blanking (DPB) is introduced to fully use the power while reducing energy consumption...
In this paper, we consider an opportunistic beamforming scheduling scheme of secondary users (SUs) which can share the spectrum with a primary user (PU) in an underlay cognitive radio network. In the scheduling process, the cognitive base station (CBS) having multi-antennas, generates orthogonal beams which insure the minimum interference to the PU. Then, each SU feeds back its maximum signal to interference...
Frequency reuse-1 model is required to satisfy the exponential increase of data demands in mobile networks, such as the Long Term Evolution (LTE) of Universal Mobile Terrestrial radio access System (UMTS). However, the simultaneous usage of the same frequency resources in adjacent LTE cells creates inter-cell interference problems, that mainly affect cell-edge users. Inter-Cell Interference Coordination...
LTE is rapidly gaining momentum for building future 4G cellular systems, and real operational networks are under deployment worldwide. To achieve high throughput performance, in addition to an advanced physical layer design LTE exploits a combination of sophisticated mechanisms at the radio resource management layer. Clearly, this makes difficult to develop analytical tools to accurately assess and...
This paper considers the design of a cross-layer medium access control (MAC) protocol for wireless ad hoc cooperative networks. Specifically, we redesign the message exchange process of the MAC protocol previously proposed by Shan et al. By using a HRP signal with shorter length the proposed protocol can reduce the protocol overhead and thus improve the transmission reliability. We also propose to...
We consider heterogeneous network (HetNet) systems comprising of two different types of base-stations (BSs): macro and small BSs. In the previous studies for HetNet, it is observed that the distribution of signal to interference plus noise ratio (SINR) is independent of the BS density. This implies that network throughput increases linearly with the number of BSs. In this paper, however, we have identified...
Wireless link adaptation configures the physical layer of the transmitter in the presence of dynamic channel conditions to maximize link performance under error rate reliability constraints. Typically, error rate reliability targets are defined externally and remain fixed, regardless of the physical layer configuration. In this paper, we allow link adaptation to define its own error rate reliability...
Dynamic spectrum access is an effective approach to improve the spectrum utilization. When primary user (PU) leases its spectrum to secondary users (SU), the spectrum efficiency can be enhanced, however, PU might be interfered by the co-existence of SU. This paper considers the situation that PU is willing to coexist with SU once it is paid and its Signal to Interference-plus-Noise Ratio (SINR) is...
Most current cellular mobile communication systems employ 1-cell frequency reuse to achieve high spectrum efficiency. With 1-cell frequency reuse, the co-channel interference among cells remains a critical barrier to achieving further improvements in the spectrum efficiency. Vertical plane beam control at the base station is one approach to mitigating the co-channel interference. The conventional...
In this paper, we investigate multi-cell coordinated scheduling and power allocation in downlink long term evolution advanced (LTE-A) systems, where orthogonal frequency division multiple-access (OFDMA) is used. The proposed scheme performs joint scheduling, power allocation, and modulation and coding scheme (MCS) selection to maximize the overall weighted throughput with proportional fairness. Our...
Adaptive Modulation and Coding (AMC) in LTE networks is commonly employed to improve system throughput by ensuring more reliable transmissions. Most of existing AMC methods select the modulation and coding scheme (MCS) using pre-computed mappings between MCS indexes and channel quality indicator (CQI) feedbacks that are periodically sent by the receivers. However, the effectiveness of this approach...
Pico eNodeBs (PeNB) are deployed in 3GPP LTE-A networks to improve the overall performance. However, the inter cell interference may become severe without suitable coordination. In this paper, a dynamic distributed power control scheme is proposed. First, each PeNB gathers information about pico user equipments (PUE) in this cell and macro user equipments (MUE) this PeNB is interfering. Then, in power...
Resource allocation is one of the key issues in long term evolution (LTE) systems. In this paper, we propose an adaptive resource allocation scheme with quality of service (QoS) guarantees to maximize system throughput for high-speed mobile LTE systems. In this scheme, considering that channel quality indicator (CQI) might be changed in fast mobile scenarios which can reduce the system throughput,...
A resource allocation scheme involving several Device-to-Device (D2D) multicast groups underlaying OFDMA-based systems is proposed in this paper. In order to guarantee Quality of service (QoS) of cellular users (CeUEs), we define the signal-to-interference-pulse noise ratio (SINR) threshold value for CeUEs. Meanwhile, the minimum throughput of a single D2D multicast group is predetermined to maintain...
In traditional cellular networks, User Equipments (UEs) always connect to the strongest Base Station (BS), which offers either the maximum Signal to Interference Plus Noise Ratio (SINR) or the best Reference Signal Received Power (RSRP). However, in heterogeneous networks, due to a large difference of transmit power between macrocells and low power nodes, the user association methods mentioned above...
Wireless heterogeneous networks have emerged as a new paradigm to meet the fast increasing wireless capacity and coverage demands. Coordinated Multipoint Processing (CoMP) and Precoding are two promising techniques to further improve the network capacity and spectral efficiency. This paper presents an optimal intra-cell CoMP resource allocation scheme in a wireless heterogeneous network and explores...
In this paper, we propose a priority based scheduling algorithm for Mobile Ad-hoc Network (MANET) using fuzzy logic. The fuzzy system has three inputs: data rate, Signal-to-Noise Ratio (SNR) and queue size. The fuzzy system was verified using MATLAB fuzzy toolbox and the performance of the algorithm was evaluated using OPNET simulator. The results were compared to an existing fuzzy scheduler. The...
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