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Non-Orthogonal Multiple Access (NOMA) is a promising multiple access technique for 5G wireless communication networks due to its higher spectral efficiency and user fairness. Power allocation is the key to improve the performance of NOMA systems. In this paper, we focus on a certain NOMA group of a hybrid NOMA system. We formulate a sum-throughput maximization problem for uplink under the constraints...
Co-channel interference is a dominant limiting factor for LTE uplink system capacity. BS (Base station) MMSE-IRC (Minimum mean square error — interference rejection combining) receiver, as a promising approach for spatial domain interference handling, is introduced in LTE-Advanced Release 13. This paper firstly gives the signal model and receiver structure for BS MMSE-IRC. To evaluate MMSE-IRC performance...
The standardization for the fifth generation (5G) of mobile and wireless networks is at its early phase and has recently completed the first study item in Release 14. Nevertheless, there is a consensus that 5G will address the diverse service requirements of high-variety use cases. The network shall cope with such variation effectively and cost-efficiently even though the requirements can change over...
In this paper, we analyze the performance of the fractional pilot reuse (FPR) scheme with vertical sectorization in massive multiple-input multiple-output (MIMO) system. In this scheme, users are classified into the cell-center ones in inner vertical sector and the cell-edge ones in outer vertical sector according to their signal-to-interference-plus- noise ratios (SINRs) at the receiver side. Then,...
This paper presents a method for designing linear-phase square-root (SR) FIR digital filters that alleviate the effect of receiver timing uncertainty by the quadratically constrained quadratic programming. As in the previous work, we take the “roughness” of the hybrid analog/FIR-SR filter impulse response as the cost function and the filter's stopband attenuation and the system's tolerable ISI as...
This paper proposes a Mobility and Activeness aware Relay Selection (MARS) algorithm for multi-hop D2D communication underlaying cellular networks. MARS takes into account the activeness and mobility of a user device in relay selection, and introduces an activeness factor and a mobility factor in calculating the utility gain of the system brought by a relay candidate. To select a relay for a pair...
In this paper, flexible frequency division duplex (FDD) and time division duplex (TDD) schemes are considered in FDD spectrum. With FDD spectrum, there is a paired uplink (UL) carrier with each downlink (DL) carrier, each carrier with the same bandwidth. Because equal resources are provisioned for the DL and UL, FDD spectrum is not well suited for asymmetric DL/UL traffic. While the FDD UL-paired...
Device-to-Device (D2D) communications are considered as one of the key technologies for 5G wireless communication systems. In this paper, a frequency reuse scheme, in which multiple D2D links share spectrum resources with multiple cellular links simultaneously, is studied. Two novel concepts are introduced, namely the D2D pool and the cellular pool. D2D links in the D2D pool reuse uplink resource...
The integration of millimeter-wave base stations (mmW- BSs) with conventional microwave base stations (μW-BSs) is a promising solution for enhancing the quality-of- service (QoS) of emerging 5G networks. However, the significant differences in the signal propagation characteristics over the mmW and μW frequency bands will require novel cell association schemes cognizant of both mmW...
Recent studies have demonstrated that millimeter-wave cellular networks may operate either in the noise-or in the interference-limited regime, depending on several parameters, which include the density of base stations, the density and size of obstacles/blockages, the antenna beamwidth, and the transmission bandwidth. The objective of the present paper is to exploit tools from stochastic geometry...
We present the application of statistical classifiers to the problem of automatic identification of radio frequency interference (RFI) in radio astronomy. RFI can corrupt measurements made by radio telescopes and it is therefore very important that such interference can be identified. We compile a dataset of RFI signals gathered at the SKA site near Carnavon, South Africa, and use this data to train...
Recently, researches on mobile cognitive radio network (CRN) has been paid more attention to, involving spectrum sensing, power control and spectrum access, while no schemes considering both the power and spectrum assignment at the same time. In this paper, an efficient resource allocation (RA) scheme is proposed for the orthogonal frequency division multiple access (OFDMA)-based mobile underlay CRN...
This paper presents the design of a dual feed horn system for Satellite Broadband and TV Integrated IP Solution (SBaTIIPS). The feed horn allows coherent operations of Ku DBS TV and Ka broadband internet from a common dish antenna. System requirements, specifications, designs and measurements are shown in this paper.
The demand for increasingly challenging data rates in cellular networks has motivated the pursuit to exploit abundant bandwidth at the millimeter waves (mmWave) spectrum, which offers large bandwidths and near free-space path loss for line of sight links. However, this solution comes at the cost of limited communication range. Thus, mmWave basestations (BS) are expected to be densely deployed to maximize...
The Coverage and Capacity are the essential parameters that defines the performance of a cellular system. But, these are restricted by the interference in the system. The Co-Channel Interference(CCI) is one of the major sources of interference which exists mainly due to the concept of frequency reuse. The effect of CCI is more in CDMA based systems because the frequency reuse ratio is unity in those...
In this paper, we study robust spectrum sharing under channel uncertainty in a cognitive radio network (CRN), where a great number of secondary users (SUs) and a primary user (PU) coexist with each other sharing the same frequency spectrum. Considering the practical challenge that the channel gain between SU transmitters (SU-Txs) and PU receiver (PU-Rx) is typically uncertain, a probabilistic interference...
It is well known that the time-of-flight ranging performance is heavy influenced by multipath propagation within a radio environment. This holds in particular in dense multipath channels as encountered in indoor scenarios. The signal bandwidth has a tremendous influence on this effect, as it determines whether the time resolution is sufficient to resolve the useful line-of-sight (LOS) signal component...
Full duplex allows a device to transmit and receive simultaneously in the same frequency band, theoretically doubling the throughput compared to traditional half duplex systems. However, several limitations restrict the promised full duplex gain: non-ideal self-interference cancellation, increased inter-cell interference and traffic constraints. In this paper, we first study the self-interference...
First, the paper analyzes the basic principle of the uplink MU-MIMO and gives the user matching conditions and application suggestion. Then, an estimation method of uplink MU-MIMO gain is presented based on the tests analysis. At last, the performance of uplink MU-MIMO in the current user condition is also given.
A unique wide band receiver for radio astronomy has been designed and constructed. Receivers used for radio astronomy consist of two parts, the front end cold electronics and the back end warm electronics. While the cold electronics provides for a low noise amplifier and receiver calibrations, the warm electronics provides analog signal processing that shapes and filters the signals before digitizing...
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