Performance analysis for relay networks with hierarchical support vector machines

Abstract

SUMMARY In this paper, we consider a cooperative relay scheme for a mobile network with MIMO technology. The channel capacity for two well‐known relaying schemes are investigated: analogue relaying (amplify and forward) and digital relaying (decode and forward) from a mobile device to the base station through a relay node. In order to further increase the channel capacity, we propose an efficient hierarchical procedure based on support vector machine, namely hierarchical support vector machines (HSVM), to estimate the wireless networks condition approximately and design two ways (matched filter and minimum mean square error filter) of increasing the channel capacity according to the estimated wireless network condition. The proposed HSVM can estimate the wireless networks condition in much shorter time compared with the traditional minimum mean square error scheme without incurring much estimation error, which is spatial, useful for delay sensitive communication. For digital relaying, the effect of imperfect channel decode is also addressed. Our numerical results demonstrate the reduction of estimation complexity by adopting HSVM and the significant improvement of network capacity by applying the matched filter weight at relay nodes according to the network estimation. Copyright © 2011 John Wiley & Sons, Ltd.

ADS‐B aided robust relay selection for cooperative communications in aircraft approach

“…(2), (5), and (6) in Section III, the estimated average SNRs Q id , Q sd , and the estimated average decoding probability Q P dsi can be obtained. Initially, given the position O X k 1=k 1 and error covariance P k 1=k 1 at time k 1, the corresponding values at time k are predicted according to (15a) and (15b), respectively, where Q k 1 is the covariance of interference noise.…”

“…In the last decade, cooperative communication technique has received much attention in the communication society [5][6][7], which is proved to be effective in combating multipath fading by exploiting the spatial diversity of the relay nodes. In our work, we consider the application of cooperative communication technique in the aircraft approach scenario.…”

“…

The ground-to-air communications in the aircraft approach stage suffer from multipath fading. However, because of the high speed and low elevation of the approaching aircraft, the performance of point-to-point data link suffers from serious multipath fading in the flight test [3,4].In the last decade, cooperative communication technique has received much attention in the communication society [5][6][7], which is proved to be effective in combating multipath fading by exploiting the spatial diversity of the relay nodes. The relay selection problem is formulated to minimize the spectrum cost while preserving the signal-to-noise-ratio (SNR) outage requirement of the approaching aircraft.

…”

Low complexity timing estimation and resynchronization for asynchronous bidirectional communications with multiple antenna relay

“…Wireless relaying is an efficient method to increase throughput and extend coverage of wireless networks [1][2][3][4][5]. So far, most existing works on relay networks assume perfect synchronization among different wireless nodes.…”

Investigation of phantom circuit benefits for next generation xDSL systems

“…The discrete multi-tone modulation (DMT) will be enhanced by the process of vectoring [6] (VDMT) for the elimination of far-end crosstalk (FEXT), which is the dominant source of noises and disturbances in xDSL systems nowadays [7]. However, the application of VDMT and the process of DMT symbol coordination in large cable binders are computationally very demanding [8]; therefore, several scenarios with only partial VDMT application are being considered [9]. The methods for elimination of impulsive noise [10,11] as well as problems related with vectoring process used in VDMT [12] and high number of its sub-channels [13,14] are being discussed as well [15].…”