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Based on the zero correlation zone (ZCZ) concept, we present the definition and properties of a set of new triphase coded waveforms -ZCZ sequence-pair set (ZCZPS) in this paper and propose a method to use the optimized punctured sequence-pair along with Hadamard matrix construct the optimized punctured ZCZ sequence-pair set (optimized punctured ZCZPS). According to property analysis under the Doppler...
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, we analyze the potential performance of such ??wideband?? HF data channels as a function of spectrum allocation, coding, channel characteristics, and waveform overhead.
Faced with intense competition, network service providers, supported by their respective network operations centers (NOCs), must ensure the best possible quality of service (QoS) and corresponding quality of experience (QoE) for end-users or face the loss of business. QoE represents the perception of quality experienced by end-users of a real-time system, such as VoIP. The QoE challenge becomes significant...
DoD has defined three levels of data fusion for network centric warfare (NCW). Level 1 data fusion combines data from single or multiple sensors and sources to provide the best estimate of objects and events in the battlespace. Level 2 data fusion focuses on situation assessment. Level 3 data fusion is threat assessment. To facilitate situation assessment, we investigate the problem of jointly classifying...
In this paper, a technique for detection of wormhole attacks based on distance verification is proposed for mobile ad hoc network (MANETs) applications. A node estimates its distances to a sender node based on the received signal strength (RSS) of received packets, and uses them to verify against the distances computed from the location information in the packets. The verification is formulated as...
In this paper we propose a novel medium access control (MAC) protocol that provides spectrum agile bandwidth allocation for cognitive radios. Our MAC protocol, called spectrum agile multiple access or simply SAMA, harnesses the frequency agility of cognitive radios in allocating fair and contention free bandwidth under a heterogeneous spectrum environment. SAMA accomplishes its bandwidth allocation...
We study end-to-end delay performance of different routing algorithms in networks with random failures. Specifically, we compare delay performances of differential backlog (DB) and shortest path (SP) routing algorithms and show that DB routing outperforms SP routing in terms of throughput when the network is heavily loaded and/or the failure rate is high while SP routing achieves better delay performance...
The Network Centric Warfare (NCW) model is currently attracting attention in modern warfare research. In this model, data processing issues, such as efficiently determining enemies of high threat, are critical for optimizing war tactics. In this paper, by adopting the concept of skyline queries which have been extensively studied in database research, we address the problem of searching highly threatening...
In this paper, we discuss a general multi protocol label switching (MPLS) based traffic engineering (TE) approach for providing QoS based transportation in a geostationary satellite constellation network. As satellite constellation networks become more and more common, with on-board packet processing capabilities providing backbone services to support thousands of airborne and terrestrial terminals,...
This paper discusses a new capability, the Hybrid Pseudo-Random (HyPR) Dynamic Force Generator. This capability uses geographic position data of select ground platforms in an operational unit to quickly generate realistic, dynamic positions for the remaining unit platforms. This capability (implemented in MATLAB) was initially designed to generate scenario-linked laydowns for an entire ~3000 platform...
Robustness, security, anonymity, and scalability are valued features for mobile ad hoc network routing protocols. Unfortunately, the existing ad hoc routing protocols have limitations in each area. In this paper, we first analyze several existing mobile ad hoc routing protocols for robustness, security, anonymity, and scalability. Based on the analysis, we propose a new robust anonymous ad hoc on-demand...
The rapid migration of system high information sharing to the tactical edge has made it imperative that the DoD reexamine tactical Cross Domain Solutions/Enterprise Services (CDS/ES). Prior to Operation Iraqi Freedom (OIF), information sharing requirements at the tactical edge were relatively few in number and nominal in terms of data throughput, data types, and users. Cross Domain Solutions (CDS)...
We derive the Cramer-Rao Bound (CRB) on the performance of joint estimators for timing offset, carrier phase offset, and carrier frequency offset for use in a QPSK packet-based communication link. It is shown that the CRB is a function of the pilot or training sequence, the signal-to-noise ratio (SNR), and the pulse shape. We also compute QPSK training sequences of different lengths that minimize...
In this paper, we investigate the packet transmission delay in a time varying satellite uplink. Specifically, we are interested in bounding the packet transmission delay within the terminal router for uplink traffic in a future satellite network. Previous work has provided delay bounds for wireline networks with a fixed transmission rate. However, these bounds do not apply to the time-varying satellite...
The prerequisite of accessing white spectrum is to find and locate it. Our work deals with spectrum detection and recognition under the umbrella of cognitive radio. In the procedure of spectrum recognition, a frequency sweeping device sweeps the wideband spectrum and the samples of the wideband power spectrum density (PSD) are fed into different hidden Markov models (HMMs) sequentially. The core idea...
In this paper, we propose two modified proportional fair scheduling algorithms for multiuser multicarrier systems. Compared to the existing proportional fair scheduling algorithms, our proposed algorithms are devised to support the delay constraint for the real-time applications as well as to guarantee a certain level of fairness. The simulation results show that the proposed scheduling algorithms...
While there are multiple reference models for data fusion, there are no formal processes in which to design a complete fusion system. Even though high-level fusion, i.e., impact and threat assessment, is included in the various models, the majority of data fusion research has focused on low-level data fusion such as sensing and correlation. More importantly, low-level fusion technologies have been...
Cooperative hybrid-ARQ (HARQ) protocols have been widely studied because they are more efficient than cooperative protocols without HARQ. In, the throughput of a cooperative HARQ protocol based on the decode-and-forward protocol (DF-HARQ) is obtained. In this paper, the maximum achievable throughput of the DF-HARQ protocol is obtained using the asymptotic outage probability when the maximum number...
A novel decoder covariance optimization approach is proposed for jointly designing the minimum mean square error (MMSE) transceivers of downlink multicell multiuser multiple-input-multiple-output (MIMO) systems subject to general linear power constraints. Per-antenna power constraint (single cell or multicell), total power constraint (single cell) and per-cell power constraint (multicell) are presented...
Three primary objectives of the Joint Program Executive Officer (JPEO) Joint Tactical Radio System (JTRS) are: (a) reduce time to field capability, (b) improve interoperability between services, and (c) decrease radio production costs. The Software Communications Architecture (SCA) specification is the architectural framework for all JTRS software artifacts that was created to maximize software application...
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