Global ETD Search

1	Chromatic number of integral distance graph Li, fu-qun 13 February 2001 (has links) Abstract For a set D of positive integers, the integral distance graph G(Z, D) is the graph with vertex set Z and edge set { xy : x, y 2 Z and \| x − y \| 2 D } . An integral distance graph G(Z, D) is called ¡§locally dense¡¨ if the clique size of G(Z, D) is not less to \| D \| . This paper acterizes locally dense integral distance graphs and determine their chromatic numbers. integral distance graph Chromatic number.
2	Low Density Parity Check (LDPC) codes for Dedicated Short Range Communications (DSRC) systems Khosroshahi, Najmeh 03 August 2011 (has links) In this eﬀort, we consider the performance of a dedicated short range communication (DSRC) system for inter-vehicle communications (IVC). The DSRC standard employs convolutional codes for forward error correction (FEC). The performance of the DSRC system is evaluated in three diﬀerent channels with convolutional codes, regular low density parity check (LDPC) codes and quasi-cyclic (QC) LDPC codes. In addition, we compare the complexity of these codes. It is shown that LDPC and QC-LDPC codes provide a signiﬁcant improvement in performance compared to convolutional codes. / Graduate Distance Graph DSRC DSRC Channel Model DSRC Physical Layer DSRC Spectrum IEEE 802.11a Physical Layer LDPC OFDM Quasi-Cyclic LDPC Sum Product Algorithm Tanner Graph Viterbi Algorithm WAVE Wireless Access Vehicular Environment