New Mexico State University

Displaying 1-21 of 21 results

  • White Papers // Nov 2012

    Hybrid FSO/RF Symbol Mappings: Merging High Speed FSO with Low Speed RF Through BICM-ID

    In this paper, the authors investigate designing of hybrid Free Space Optical (FSO)/Radio Frequency (RF) symbol mappers using Bit-Interleaved Coded Modulation with Iterative Decoding (BICM-ID) with asymmetric data rates between the FSO and the RF links. Data bits are first encoded with a channel code and the coded bits after...

    Provided By New Mexico State University

  • White Papers // Nov 2012

    Performance Evaluation of VoIP Traffic Over the IEEE 802.16e Protocol With Different Modulations and Codings

    Supporting as much Voice over IP (VoIP) users as possible in a BWA network using limited radio resources is a very important issue. However, performance of VoIP services is affected by several issues defined in the IEEE 802.16e protocol. In this paper, the authors used a theoretical model and an...

    Provided By New Mexico State University

  • White Papers // Oct 2012

    Network Equivalence in the Presence of an Eavesdropper

    The authors consider networks of noisy degraded wiretap channels in the presence of an eavesdropper. For the case where the eavesdropper can wiretap at most one channel at a time, they show that the secrecy capacity region, for a broad class of channels and any given network topology and communication...

    Provided By New Mexico State University

  • White Papers // May 2012

    Optimized Laser Beam Parameters for Communications in Space Environments in the Presence of Pointing Errors

    The authors investigate the behavior of spatially Partially Coherent Beams (PCBs) in the presence of pointing errors in the space communication environment. Closed form expressions for the optimal coherence length for minimizing outage probability and maximizing average Signal-to-Noise Ratio (SNR) are derived. In the case of outage probability, they observe...

    Provided By New Mexico State University

  • White Papers // Sep 2011

    The MultiDark Database: Release of the Bolshoi and MultiDark Cosmological Simulations

    The authors present the online Multi Dark Database - a Virtual Observatory-oriented, relational database for hosting various cosmological simulations. The data is accessible via an SQL (Structured Query Language) query interface, which also allows users to directly pose scientific questions, as shown in a number of examples in this paper....

    Provided By New Mexico State University

  • White Papers // Aug 2011

    Energy-Delay Considerations in Coded Packet Flows

    The authors consider a line of terminals which is connected by packet erasure channels and where random linear network coding is carried out at each node prior to transmission. In particular, they address an online approach in which each terminal has local information to be conveyed to the base station...

    Provided By New Mexico State University

  • White Papers // Jan 2011

    Third-Generation Technologies for HF Radio Networking

    Second-generation HF automation (e.g., MIL-STD-188- 141A) provided a sufficiently robust, reliable, and interoperable link establishment technology to produce a resurgence of interest in HF radio for long-haul and mobile voice networks beginning in the 1980s. With the addition of a robust data link protocol, the second generation technology was extended...

    Provided By New Mexico State University

  • White Papers // Jan 2011

    HF SChEMe: A Skywave Channel Error Model

    Simulation has been extensively employed to evaluate concepts included in the current generation of Automatic Link Establishment (ALE) High-Frequency (HF) radio systems. As development of HF automation proceeds from link-layer technology to network- and higher-layer technology, it is no longer necessary to devote great amounts of computer time to detailed...

    Provided By New Mexico State University

  • White Papers // Jan 2011

    Error Correction in High Frequency Automatic Link Establishment Radios With and Without Link Protection

    Error correcting techniques used by High Frequency Automatic Link Establishment (HF ALE) radios, including those with link protection, transform a basic 24-bit ALE word into 147 bits to be transmitted and received. This paper examines the effect random errors in the 147 received bits have on the received 24-bit ALE...

    Provided By New Mexico State University

  • White Papers // Nov 2010

    Equivocation of Eve Using Two Edge Type LDPC Codes for the Binary Erasure Wiretap Channel

    The authors consider transmission over a binary erasure wiretap channel using the code construction method introduced by Rathi et al. based on two edge type Low-Density Parity-Check (LDPC) codes and the coset encoding scheme. By generalizing the method of computing conditional entropy for standard LDPC ensembles introduced by M?easson, Montanari,...

    Provided By New Mexico State University

  • White Papers // Nov 2010

    On Secure Communication Over a Class of Degraded Relay Networks

    In this paper the authors consider a class of degraded relay networks with multiple receivers, address the capacity region for the multicast case, and consider information-theoretic security aspects. Exemplary, they study a degraded relay network, which is comprised of one source, an arbitrary number of relay nodes, and two receiver...

    Provided By New Mexico State University

  • White Papers // Oct 2010

    Determinants Of Capital Flight And Capital Movement Through Trade Mispricing: The African Case

    This paper attempts to accomplish two things. It tries to establish the determinants of capital flight and capital movement through trade misinvoicing from selected African countries in order to ascertain whether the same factors could explain both types of capital movement. Second, it attempts to determine whether Granger causation exists...

    Provided By New Mexico State University

  • White Papers // Aug 2010

    Language and Retrieval Accuracy

    One of the major challenges in the Information Retrieval field is handling the massive amount of information available to Internet users. Existing ranking techniques and strategies that govern the retrieval process fall short of expected accuracy. Often relevant documents are buried deep in the list of documents returned by the...

    Provided By New Mexico State University

  • White Papers // Jul 2010

    Simple and Effective Scheduling in Wireless Networks Under the Physical Interference Model

    In this paper, the authors study the problem of maximizing the number of concurrent requests and the problem of minimizing the number of time-slots needed to schedule all requests in wireless networks under the physical interference model. It has been proved that both problems are NP-complete. Thus, either approximation algorithms...

    Provided By New Mexico State University

  • White Papers // Jun 2010

    Algebraic Constructions of Graph-Based Nested Codes from Protographs

    Nested codes have been employed in a large number of communication applications as a specific case of superposition codes, for example to implement binning schemes in the presence of noise, in joint network-channel coding, or in physical-layer secrecy. Whereas nested lattice codes have been proposed recently for continuous-input channels, in...

    Provided By New Mexico State University

  • White Papers // Nov 2009

    Two Edge Type LDPC Codes for the Wiretap Channel

    The authors consider transmission over a wiretap channel where both the main channel and the wiretapper's channel are Binary Erasure Channels (BEC). They propose a code construction using two edge type LDPC codes based on the method of Thangaraj, Dihidar, Calderbank, McLaughlin and Merolla. The advantage of their construction is...

    Provided By New Mexico State University

  • White Papers // Aug 2009

    Performance Envelope of Broadband HF Data Waveforms

    Parallel efforts are underway in the frequency management and the radio and waveform design communities to support data communications over HF radio channels wider than conventional 3 kHz allocations. In this paper, the authors analyze the potential performance of such "Wideband" HF data channels as a function of spectrum allocation,...

    Provided By New Mexico State University

  • White Papers // Jun 2009

    Negotiation Using Logic Programming With Consistency Restoring Rules

    The authors formalize negotiations using logic programming with consistency restoring rules (or CR-Prolog) [Balduccini and Gelfond, 2003]. The authors' formulation deals with incomplete information, preferences, and changing goals. They assume that each agent is equipped with a knowledge base for negotiation which consists of a CR-program, a set of possible...

    Provided By New Mexico State University

  • White Papers // Apr 2009

    Logic Programming for Multiagent Planning With Negotiation

    Multiagent planning deals with the problem of generating plans for multiple agents. It requires formalizing ways for the agents to interact and cooperate, in order to achieve their goals. One way for the agents to interact is through negotiations. Integration of negotiation in multiagent planning has not been extensively investigated...

    Provided By New Mexico State University

  • White Papers // Apr 2009

    Reasoning and Planning With Cooperative Actions for Multiagents Using Answer Set Programming

    In this paper, the authors investigate the multiagent planning problem in the presence of cooperative actions and agents, which have their own goals and are willing to cooperate. To this end, they extend the action language A to represent and reason about plans with cooperative actions of an individual agent...

    Provided By New Mexico State University

  • White Papers // Nov 2008

    Justifications for Logic Programs Under Answer Set Semantics

    The paper introduces the notion of off-line justification for Answer Set Programming (ASP). Justifications provide a graph-based explanation of the truth value of an atom w.r.t. a given answer set. The paper extends also this notion to provide justification of atoms during the computation of an answer set (on-line justification),...

    Provided By New Mexico State University

  • White Papers // Jan 2011

    Third-Generation Technologies for HF Radio Networking

    Second-generation HF automation (e.g., MIL-STD-188- 141A) provided a sufficiently robust, reliable, and interoperable link establishment technology to produce a resurgence of interest in HF radio for long-haul and mobile voice networks beginning in the 1980s. With the addition of a robust data link protocol, the second generation technology was extended...

    Provided By New Mexico State University

  • White Papers // Jan 2011

    HF SChEMe: A Skywave Channel Error Model

    Simulation has been extensively employed to evaluate concepts included in the current generation of Automatic Link Establishment (ALE) High-Frequency (HF) radio systems. As development of HF automation proceeds from link-layer technology to network- and higher-layer technology, it is no longer necessary to devote great amounts of computer time to detailed...

    Provided By New Mexico State University

  • White Papers // Aug 2009

    Performance Envelope of Broadband HF Data Waveforms

    Parallel efforts are underway in the frequency management and the radio and waveform design communities to support data communications over HF radio channels wider than conventional 3 kHz allocations. In this paper, the authors analyze the potential performance of such "Wideband" HF data channels as a function of spectrum allocation,...

    Provided By New Mexico State University

  • White Papers // Jan 2011

    Error Correction in High Frequency Automatic Link Establishment Radios With and Without Link Protection

    Error correcting techniques used by High Frequency Automatic Link Establishment (HF ALE) radios, including those with link protection, transform a basic 24-bit ALE word into 147 bits to be transmitted and received. This paper examines the effect random errors in the 147 received bits have on the received 24-bit ALE...

    Provided By New Mexico State University

  • White Papers // Nov 2008

    Justifications for Logic Programs Under Answer Set Semantics

    The paper introduces the notion of off-line justification for Answer Set Programming (ASP). Justifications provide a graph-based explanation of the truth value of an atom w.r.t. a given answer set. The paper extends also this notion to provide justification of atoms during the computation of an answer set (on-line justification),...

    Provided By New Mexico State University

  • White Papers // Apr 2009

    Logic Programming for Multiagent Planning With Negotiation

    Multiagent planning deals with the problem of generating plans for multiple agents. It requires formalizing ways for the agents to interact and cooperate, in order to achieve their goals. One way for the agents to interact is through negotiations. Integration of negotiation in multiagent planning has not been extensively investigated...

    Provided By New Mexico State University

  • White Papers // Apr 2009

    Reasoning and Planning With Cooperative Actions for Multiagents Using Answer Set Programming

    In this paper, the authors investigate the multiagent planning problem in the presence of cooperative actions and agents, which have their own goals and are willing to cooperate. To this end, they extend the action language A to represent and reason about plans with cooperative actions of an individual agent...

    Provided By New Mexico State University

  • White Papers // May 2012

    Optimized Laser Beam Parameters for Communications in Space Environments in the Presence of Pointing Errors

    The authors investigate the behavior of spatially Partially Coherent Beams (PCBs) in the presence of pointing errors in the space communication environment. Closed form expressions for the optimal coherence length for minimizing outage probability and maximizing average Signal-to-Noise Ratio (SNR) are derived. In the case of outage probability, they observe...

    Provided By New Mexico State University

  • White Papers // Oct 2012

    Network Equivalence in the Presence of an Eavesdropper

    The authors consider networks of noisy degraded wiretap channels in the presence of an eavesdropper. For the case where the eavesdropper can wiretap at most one channel at a time, they show that the secrecy capacity region, for a broad class of channels and any given network topology and communication...

    Provided By New Mexico State University

  • White Papers // Sep 2011

    The MultiDark Database: Release of the Bolshoi and MultiDark Cosmological Simulations

    The authors present the online Multi Dark Database - a Virtual Observatory-oriented, relational database for hosting various cosmological simulations. The data is accessible via an SQL (Structured Query Language) query interface, which also allows users to directly pose scientific questions, as shown in a number of examples in this paper....

    Provided By New Mexico State University

  • White Papers // Nov 2012

    Hybrid FSO/RF Symbol Mappings: Merging High Speed FSO with Low Speed RF Through BICM-ID

    In this paper, the authors investigate designing of hybrid Free Space Optical (FSO)/Radio Frequency (RF) symbol mappers using Bit-Interleaved Coded Modulation with Iterative Decoding (BICM-ID) with asymmetric data rates between the FSO and the RF links. Data bits are first encoded with a channel code and the coded bits after...

    Provided By New Mexico State University

  • White Papers // Aug 2011

    Energy-Delay Considerations in Coded Packet Flows

    The authors consider a line of terminals which is connected by packet erasure channels and where random linear network coding is carried out at each node prior to transmission. In particular, they address an online approach in which each terminal has local information to be conveyed to the base station...

    Provided By New Mexico State University

  • White Papers // Nov 2010

    Equivocation of Eve Using Two Edge Type LDPC Codes for the Binary Erasure Wiretap Channel

    The authors consider transmission over a binary erasure wiretap channel using the code construction method introduced by Rathi et al. based on two edge type Low-Density Parity-Check (LDPC) codes and the coset encoding scheme. By generalizing the method of computing conditional entropy for standard LDPC ensembles introduced by M?easson, Montanari,...

    Provided By New Mexico State University

  • White Papers // Nov 2010

    On Secure Communication Over a Class of Degraded Relay Networks

    In this paper the authors consider a class of degraded relay networks with multiple receivers, address the capacity region for the multicast case, and consider information-theoretic security aspects. Exemplary, they study a degraded relay network, which is comprised of one source, an arbitrary number of relay nodes, and two receiver...

    Provided By New Mexico State University

  • White Papers // Jun 2010

    Algebraic Constructions of Graph-Based Nested Codes from Protographs

    Nested codes have been employed in a large number of communication applications as a specific case of superposition codes, for example to implement binning schemes in the presence of noise, in joint network-channel coding, or in physical-layer secrecy. Whereas nested lattice codes have been proposed recently for continuous-input channels, in...

    Provided By New Mexico State University

  • White Papers // Nov 2009

    Two Edge Type LDPC Codes for the Wiretap Channel

    The authors consider transmission over a wiretap channel where both the main channel and the wiretapper's channel are Binary Erasure Channels (BEC). They propose a code construction using two edge type LDPC codes based on the method of Thangaraj, Dihidar, Calderbank, McLaughlin and Merolla. The advantage of their construction is...

    Provided By New Mexico State University

  • White Papers // Nov 2012

    Performance Evaluation of VoIP Traffic Over the IEEE 802.16e Protocol With Different Modulations and Codings

    Supporting as much Voice over IP (VoIP) users as possible in a BWA network using limited radio resources is a very important issue. However, performance of VoIP services is affected by several issues defined in the IEEE 802.16e protocol. In this paper, the authors used a theoretical model and an...

    Provided By New Mexico State University

  • White Papers // Oct 2010

    Determinants Of Capital Flight And Capital Movement Through Trade Mispricing: The African Case

    This paper attempts to accomplish two things. It tries to establish the determinants of capital flight and capital movement through trade misinvoicing from selected African countries in order to ascertain whether the same factors could explain both types of capital movement. Second, it attempts to determine whether Granger causation exists...

    Provided By New Mexico State University

  • White Papers // Aug 2010

    Language and Retrieval Accuracy

    One of the major challenges in the Information Retrieval field is handling the massive amount of information available to Internet users. Existing ranking techniques and strategies that govern the retrieval process fall short of expected accuracy. Often relevant documents are buried deep in the list of documents returned by the...

    Provided By New Mexico State University

  • White Papers // Jun 2009

    Negotiation Using Logic Programming With Consistency Restoring Rules

    The authors formalize negotiations using logic programming with consistency restoring rules (or CR-Prolog) [Balduccini and Gelfond, 2003]. The authors' formulation deals with incomplete information, preferences, and changing goals. They assume that each agent is equipped with a knowledge base for negotiation which consists of a CR-program, a set of possible...

    Provided By New Mexico State University

  • White Papers // Jul 2010

    Simple and Effective Scheduling in Wireless Networks Under the Physical Interference Model

    In this paper, the authors study the problem of maximizing the number of concurrent requests and the problem of minimizing the number of time-slots needed to schedule all requests in wireless networks under the physical interference model. It has been proved that both problems are NP-complete. Thus, either approximation algorithms...

    Provided By New Mexico State University