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In this paper, we analyze the performance of the fractional pilot reuse (FPR) scheme with pilot contamination mitigation in massive multiple-input multiple-output (MIMO) system. In FPR, users are classified into the cell- center and the cell-edge ones according to their signal-to- interference-plus-noise ratios (SINRs) at the receiver side. Then, the cell- edge users with low SINRs in different cells...
The fifth-generation (5G) mobile communication system has attracted much attention to provide various kinds of mobile services and applications for 2020 and later. 28 GHz band is one of the most potent bands for 5G since super wide bandwidth of almost 1 GHz will be available. In the high frequency band, beamforming is mandatory to compensate large path loss. Hence beam tracking mechanism is important...
In this paper, we investigate a Raptor-coded distributed noncoherent scheme based on a non-orthogonal spacetime modulation (NOSTM) signal and a dynamic decode-andforward (DF) relaying scenario. The distributed NOSTM signal is firstly proposed based on unitary space-time modulation (USTM) and spatial multiplexing (SM). The dynamic DF relaying protocol is investigated to process the non-orthogonal feature...
In recent years, advances in wireless local area network (WLAN) systems have led to large increases in the transmission speed. The IEEE 802.11ac standard allows for very high transmissions by using multi-user multiple input multiple output (MU-MIMO) techniques in the physical (PHY) layer. However, the transmission efficiency is decreased by the channel state information (CSI) estimation algorithm...
Device-to-Device (D2D) communication has drawn great interest in academia and industries due to the extended network coverage and reduction of the restrictions of traditional cellular systems. On the other hand, a new paradigm called content-centric networking (CCN) has been proposed for scalable, flexible, and secure services in the future networks. With CCN, it is possible to increase the throughput...
This work presents the first integration of a message-passing detector (MPD) and a polar decoder. A soft-output MPD, which is essential to approach the channel capacity, is first proposed. Compared to the state-of-the-art design, the proposed MPD achieves a 6.9x higher throughput with 49% lower energy, despite the soft outputs. The proposed polar decoder achieves a 1.35x higher throughput with comparable...
Despite the promising benefits of the cloud-radio access network (C-RAN), the fronthaul (FH) imposes stringent requirements in terms of data rate, latency, jitter and synchronisation. In the classical C-RAN, the FH capacity scales linearly with the number of the transmitting antennas, which has posed severe demands on the FH capacity, especially due to emerging 5G technologies such as massive MIMO...
The effect of the probe ring size in OTA test systems was studied based on simulations and OTA measurements in the anechoic chamber of the University of Oulu. The results are presented for two methodologies: Prefaded Synthesis (PFS) and Plane Wave Synthesis (PWS). Each size and synthesis type was validated for UMI and Uma radio channel models and for the cases the DUT in free space and in phantom...
Wi-Fi is the dominant wireless indoor broadband solution and thus key for meeting the exponential traffic growth. The recent IEEE 802.11ac amendment enables PHY data rates exceeding 1 Gbps. However, it is not clear how this increased per-link performance, achieved especially via wider channels, translates to network-level performance. The latter is crucial for understanding the true potential of emerging...
The downlink coverage of a 5G trial system operating within the 15 GHz frequency band is evaluated in this paper with the help of drive test measurements. Key 5G features, such as beamforming, beam tracking and multi-point transmission have been utilized during the measurements. The results indicate that multi-point transmission provides a clear improvement to the downlink coverage. Received signal...
In this paper we present the first cross-layer analysis of wireless LANs operating under downlink multi-user MIMO (MU-MIMO), considering the fundamental role played by closed-loop (TCP) traffic. In particular, we consider an 802.11ac scenario in which the access point transmits on the downlink via MU-MIMO, whereas stations must employ single-user transmissions on the uplink. With the help of analytical...
Multi-User Multiple Input Multiple Output (MU-MIMO) enables a multi-antenna access point (AP) to serve multiple users simultaneously, and has been adopted as the IEEE 802.11ac standard. While several PHY-MAC designs have recently been proposed to improve the throughput performance of a MU-MIMO WLAN, they, however, usually assume that all the concurrent streams are of roughly equal length. In reality,...
Large-scale MU-MIMO is a promising technology to scale network capacity and the capacity gain grows linearly with the numbers of antennas and users in theory. However, its practical deployment faces three critical challenges in the state-of-the-art WLANs: i) the demand of a large number of expensive RF chains; ii) the linear growth of feedback overheads with the number of antennas; iii) the lack of...
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...
Energy harvesting wireless nodes provide much longer lifetime and higher energy efficiency for wireless networks compared to battery operated systems. In this paper, we study a MIMO wireless communication link in which the nodes are equipped with energy harvesters and rechargeable batteries that are continuously charging from a renewable energy source. Since the harvested energy arrival and thus the...
The 5G physical layer will support applications with different requirements, such as high data rate, ultra low power consumption and low latency. Recently, there is significant interest in the design and performance of new waveforms for 5G. One of the most important candidates is the Generalised Frequency Division Multiplexing (GFDM) waveform. The new waveform must support a smooth transition from...
In this paper, we investigate the throughput analysis for the MIMOMAX protocol, a cross-layer design based on multiple transmit and receive antennas (MIMO) capabilities. We propose an analytical model based on a three-dimensional Markov chain. This model includes two additional parameters than the conventional model: a) non-saturated traffic situation, and b) beam strength at the receiver. Each beam...
In this paper, the MIMO system performance under different antenna configurations is studied based on the single frequency network (SFN) MIMO channel model in the high-speed railway scenarios. From the perspective of antenna correlation, the system throughput under linear arrays and circular arrays are simulated. The results show that the system throughput in the 2 × 2 MIMO system using space division...
Long Term Evolution (LTE) technology gives access to higher bandwidth and assures efficiency at network level for telecommunication operators, providing a reliable and continuous data traffic flow that allows data transmission at extremely high bit-rates. The aim of this paper is to evaluate LTE network performance in an actual urban environment, with emphasis on the downlink channel throughput. The...
In this paper, we investigate the performances of schedulers, which basically allocate the resources to multiple users based on different algorithms, in multiple-input multiple-output (MIMO) and orthogonal frequency division multiple access (OFDMA) based cellular wireless networks. In addition to conventional OFDMA resources which are time and frequency, antennas are also considered as resource during...
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