The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The growing demand in indoor small cell networks has given rise to the concept of micro-operators (MOs) for local service delivery. We model and analyze a spectrum sharing system involving such MOs where a buyer MO buys multiple licensed subbands provided by the regulator. All small cell base stations (SBSs) owned by a buyer MO can utilize multiple licensed subbands. Once the buyer MO obtain subbands,...
With the continuous increase of mobile Internet traffic, the user-centric ultra-dense network (UUDN) is proposed as one of the promising solutions to provide very high area throughput density and flexible access service for users. The limited radio resources cause serious competition among numerous APs. Thus, Non-orthogonal multiple access (NOMA), which supports multiple signals transmission on the...
In this paper, the outage performance of nonorthogonal multiple access (NOMA) is investigated in a downlink space division multiple access (SDMA) network with a multi-antenna base station and randomly deployed users. The NOMA technology is concurrently exploited with SDMA to further improve spectral efficiency. With limited channel state information (CSI) feedback taken into account, an analytical...
Massive Multiple-Input Multiple-Output (MIMO), small cell, and full-duplex are promising techniques for future 5G communication systems, where interference has become the most challenging issue to be coped with. In this paper, we provide an interference coordination framework for a two-tier heterogeneous network (HetNet) that consists of a massive-MIMO enabled macro-cell base station (MBS) and a number...
Non-orthogonal multiple access (NOMA) has recently been proposed as a key enabling technology for the fifth generation (5G) wireless networks. Different from the existing works which focus on the performance analysis of NOMA with backlogged traffic, in this paper, we analyze the stable throughput region of downlink NOMA transmission with dynamic traffic arrival for users with different priorities...
This work encompasses Rate-Splitting (RS), providing significant benefits in multi-user settings in the context of huge degrees of freedom promised by massive Multiple-Input Multiple-Output (MIMO). However, the requirement of massive MIMO for cost-efficient implementation makes them more prone to hardware imperfections such as phase noise (PN). As a result, we focus on a realistic broadcast channel...
Distributed antenna systems (DAS) is a promising approach to cope with challenges of next generation mobile communications. This paper studies the downlink ergodic capacity of a (N, K), (K ≤ N), virtual cell based DAS, in which each mobile station (MS) selects the N closest antenna ports (APs) to form its virtual cell and the K closest APs will serve the target MS cooperatively with a total transmit...
This paper develops a mathematical paradigm to study downlink error rates and throughput for half-duplex (HD) terminals served by a full-duplex (FD) base station (BS). Particularly, we study the dominant intra-cell interferer problem that appears between HD users scheduled on the same FD-channel. The distribution of the dominant interference is first characterized via its distribution function, which...
Cellular heterogeneous networks (HetNets) with densely deployed small cells can effectively boost network capacity. The co-channel interference and the prominent energy consumption are two crucial issues in HetNets which need to be addressed. Taking the traffic variations into account, in this paper, the performances of HetNets with joint further-enhanced inter-cell interference coordination (FeICIC)...
Full duplex (FD) communications, which increases spectral efficiency through simultaneous transmission and reception on the same frequency band, is a promising technology to meet the demand of next generation wireless networks. In this paper, we consider the application of such FD communication to self-backhauled small cells. We consider a FD capable small cell base station (BS) being wirelessly backhauled...
In this paper, we investigate the energy-efficient resource allocation problem in the downlink of an Orthogonal Frequency Division Multiple Access (OFDMA) system with multiple users. A iterative algorithm is developed to maximize the overall energy efficiency of the downlink transmission by allocating the resource blocks (RBs) and the transmit power, which is constant for all RBs assigned to a given...
Non-Orthogonal Multiple Access (NOMA) is a key multiple access technique for 5th generation (5G) mobile communication systems. In this paper, we propose a capacity-based user selection (NOMA-CUS) algorithm for multiuser multiple input single output (MISO) downlink NOMA system with zero-forcing beamforming. NOMA-CUS algorithm improves the sum rate of the NOMA system by selecting the users in each cluster...
Heterogeneity is one of the most significant features of next generation (5G) wireless networks. The spatial distribution of users in heterogeneous networks (HetNets) impacts the system performance. Currently it is often assumed that spatial users are uniformly distributed, i.e. Poisson point process (PPP). A more realistic user distribution model is a Poisson cluster process (PCP) because current...
This paper studies the power minimization problem for non-orthogonal multiple access (NOMA) downlink systems, in which nodes are equipped with multiple antennas. We develop a joint power allocation and receive beamforming algorithm using the fixed-point update power allocation method under two types of channel state information (CSI). Particularly, we first assume that perfect CSI is available for...
In this paper, a two-stage opportunistic interference alignment (OIA) algorithm is proposed for the downlink multi-cell multi-user multiple-input-multiple-output (MU-MIMO) system. Two precoders/postcoders are used at each transmitter/receiver respectively to combat interference. The inner precoder/postcoder pair are used to cancel out the inter-cell interference (ICI) using perfect IA approach, while...
In this paper, we study the average downlink rate in Ultra-Dense Networks (UDNs) considering the idle mode capability of the base stations (BSs). Wireless networks are densified by deploying a surplus of small cells in order to provide uniform coverage and high capacity. Consequently, the density of the small cells outpaces that of the active users in UDNs. Idle mode capability permits the idle BSs,...
Optimizing radio transmission power and user data rates in wireless systems requires full system observability. While the problem has been extensively studied in the literature, practical solutions approaching optimality exploiting only the partial observability available in real systems are still lacking. This paper proposes a reinforcement learning approach to downlink power control and rate adaptation...
Two-stage precoding is a promising transmission strategy for multi-user frequency division duplex (FDD) massive multiple-input multiple-output (MIMO) systems due to its large multiplexing gain with overhead reduction in both downlink channel estimation and channel state information (CSI) feedback. The performance of existing two-stage precoding schemes mainly depends on appropriate selection and clustering...
Non-orthogonal multiple access (NOMA) has attracted a lot of attention recently due to its superior spectral efficiency and could play a vital role in improving the capacity of future networks. This paper considers resource allocation for a downlink, multi-user (MU) MIMO-NOMA system that aims at maximizing the sum rate with interference alignment (IA) technique. Using singular decomposition value...
Large-scale (a.k.a. Massive) Multiple-Input Multiple-Output (MIMO) systems are considered as a strong candidate to meet the exceptionally high spectral efficiency requirements for “beyond 4G” (or commonly termed 5G) wireless communications systems. For such systems, the availability of accurate uplink channel knowledge at the base station is critical to success, particularly in the time-division duplex...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.