Engineering Commons^™

Spectral-Efficiency Of Multi-Antenna Links In Ad-Hoc Networks With Limited Tx Csi, Siddhartan Govindasamy, Daniel Bliss, David Staelin

Siddhartan Govindasamy

An asymptotic expression is derived for the mean spectral efficiency of multi-antenna links randomly distributed on a plane in a uniform manner where transmitters (Tx) have Channel-State-Information (CSI) of the channels between themselves and their target receivers while receivers (Rx) have CSI between themselves and all transmitters. The mean per-link spectral efficiency in the network is found to increase if nodes transmit using a subset of their strongest channel modes instead of the link-optimal strategy of water-filling on all channel modes (Farrokhi et al.). For reasonable parameters, this system which requires limited Tx CSI, has approximately double the mean spectral …

A Performance Analysis Of The Optimized Link State Routing Protocol Using Voice Traffic Over Mobile Ad Hoc Networks, André Wolf

Theses and Dissertations

Mobile ad hoc networks (MANETs) have grown in popularity over the past decade and are increasingly considered for time-sensitive multimedia applications. The impact of various routing protocols on voice traffic using different IEEE 802.11 extensions has been investigated via analytical models, simulations and experimental test beds. Many studies determined that optimized link state routing (OLSR) is a suitable routing protocol to support voice over internet protocol (VoIP) conversations. This research expands upon this understanding by determining the point at which voice traffic is no longer feasible in an ad hoc environment and determines which audio codec is best suited for …

Distributed Spectrum Leasing Via Cooperation, Tariq Elkourdi

Dissertations

“Cognitive radio” networks enable the coexistence of primary (licensed) and secondary (unlicensed) terminals. Conventional frameworks, namely commons and property-rights models, while being promising in certain aspects, appear to have significant drawbacks for implementation of large-scale distributed cognitive radio networks, due to the technological and theoretical limits on the ability of secondary activity to perform effective spectrum sensing and on the stringent constraints on protocols and architectures.

To address the problems highlighted above, the framework of distributed spectrum leasing via cross-layer cooperation (DiSC) has been recently proposed as a basic mechanism to guide the design of decentralized cognitive radio networks. According …