Type
Text
Type
Thesis
Advisor
Wang, Xin | Ye, Fan
Date
2016-12-01
Keywords
Electrical engineering | Capacity, Delay Tolerant Network, MU-MIMO, Precoding, VANET, Zero Forcing
Department
Department of Electrical Engineering
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/77442
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Part 1. In this paper, we learn how to select the Delay Tolerant Network (DTN) routing protocols according to dynamic network environment in wireless ad hoc network. Basically, providing access to the Internet or other network services with low mobile density is quite difficult for disconnection and long delay. One of the solutions in this problem is using Vehicular Ad-hoc Networks (VANET) with DTN. There are a variety of DTNs, relying on the different network environment. We categorize the DTNs routing protocols. Also, we use simulations to compare that DTN routing protocols lead to reduce end-to-end delay and higher message delivery ratio. For example, Epidemic takes disadvantages in terms of longer delay time and many bundle duplicate copies in high node density. It can lead into collisions and retransmissions. We simulate Binary Spray and Wait, and ProPHET (Probability routing protocol using history of encounters and transitivity) which has shorter delay time and less duplicated bundle receipt. We used the Network Simulator 2 (NS-2) to implement DTN protocols as Epidemic, Binary Spray and Wait and ProPHET to compare in different network environments. This simulation result presents that which routing protocol gives better performance. Part 2. Multi-user multiple-input multiple-output (MU-MIMO) system provides higher capacity gain if the transmitter knows the channel state information (CSI). Precoding techniques require each antenna to transmit a pre-coded data. Particularly, the precoding techniques such as zero forcing (ZF) and minimum mean square error (MMSE) have been provided for optimal capacity in the system. In this paper, we compare the capacity based on different antennas numbers with ZF and MMSE. We apply the two types of precoding to multiple antennas, considering MU-MIMO downlink with varying number of users. The optimal precoding scheme is different depending on the relative relationship between the transmitter number and the receiver number. The simulation results demonstrate that different combinations of transmitting and receiving antennas have different effect on the capacity. Based on the observations from the simulation results, we propose adaptive precoding scheme for down link (DL) transmissions in order to achieve the capacity-approaching performance in different operational environments. | 75 pages
Recommended Citation
LYU, TAEK KEUN, "Part 1. A Study on Delay Tolerant Network Algorithm for VANET Part 2. An Efficient MU-MIMO Precoding Operation with ZF and MMSE" (2016). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 3257.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/3257