The paper presents an electromagnetic Interference and Compatibility Analysis for ARABSAT and Eutelsat Networks. The analysis suggests that ARABSAT has to accept certain constraints required to protect Eutelsat. An EIRP spectral density of -34 dBW/Hz in the direction of the Eutelsat space station is proposed in the uplink bands 14.0 14.5 GHz. In the downlink bands, an EIRP spectral density of -...

Abstract—Previous studies on analog network-coded two-way relay (ANC-TWR) assumed the same modulation and coding both for the mobile terminal (MT)-relay station (RS) link and the base station (BS)-RS link. In this paper, we propose an adaptive ANC-TWR, where adaptive modulation and coding (AMC) is employed in order to maximize the uplink (MT-RS-BS) and downlink (BS-RS-MT) throughputs. The singl...

Deploying femtocell in heterogeneous network (HetNets) are promising because of improved coverage as well as system capacity. The challenge for inter-cell and intra-cell interference has taken seriously by the industry. However, some distinctive characteristics presents key problem to mitigate the interference. The random deployment of femtocell (HeNodeB) and other small cell in HetNet becomes ...

This paper proposes a new transmission strategy for the multiuser massive multiple-input multipleoutput (MIMO) systems, including uplink/downlink channel estimation and user scheduling for data transmission. A discrete Fourier transform (DFT) aided spatial basis expansion model (SBEM) is first introduced to represent the uplink/downlink channels with much few parameter dimensions by exploiting ...

Time division duplex multi-carrier code-division multiple-access (TDD/MC-CDMA) operates on the premise that there is a strong correlation between upand downlink channel conditions. When using TDD mode, the effects of the channel on the uplink signal can be pre-compensated at the mobile station, based on the channel estimation from the downlink frame. The aim of this paper is to carry out a perf...

A satellite communications system is based on antennas in a stable orbit above the earth. Satellites serve as relay stations in the sky. The basic idea of satellite communications is that two stations on earth discuss via one or more satellites. So a little bit of satellite-related terminology: 1. Earth station is an antenna on or near the surface of the earth. 2. Uplink is a transmission from ...

In this contribution, we consider the effect of timing jitter on the performance of the multicarrier direct-sequence CDMA (MCDS-CDMA) system and compare the results for uplink and downlink transmission, assuming orthogonal spreading sequences. Theoretical expressions are derived for the performance degradation caused by the timing jitter, in the presence of a multipath channel. Assuming an AWGN...

This paper addresses the filter design issues for multi-user cooperative non-regenerative MIMO relay systems in both downlink and uplink scenario. Based on the formulated signal model, the filter matrix optimization is first performed for direct path and relay path respectively, aiming to minimize the mean squared error (MSE). To be more specific, for the relay path, we derive the local optimal...

We present a full-duplex bidirectional data transmission link using twisted lights multiplexing over 1.1-km orbital angular momentum (OAM) fiber. OAM+1 and OAM-1 modes carrying 20-Gbit/s quadrature phase-shift keying (QPSK) signals are employed in the downlink and uplink transmission experiments. The observed mode crosstalks are less than -15.2 dB, and the full-duplex crosstalks are less than -...

This paper studies an unmanned aerial vehicle (UAV)-enabled wireless powered communication network (WPCN), in which a UAV is dispatched as a mobile access point (AP) to serve a set of ground users periodically. The UAV employs the radio frequency (RF) wireless power transfer (WPT) to charge the users in the downlink, and the users use the harvested RF energy to send independent information to t...