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This paper introduces and analyzes scale-time offset robust modulation (STORM) for use in code division multiaccess (CDMA) systems using spread quadrature phase shift keying (QPSK) to increase the capacity of a CDMA network. Since current commercial CDMA systems have dedicated spectrum, the capacity is primarily limited by the interference of other CDMA users; thus, power control and multiuser interference...
The DARPA CORONET program is laying the foundations for a next generation IP-over-optical network that supports 100 Tbps of traffic and provides rapid, on-demand, switched wavelength services. The wavelength services are very dynamic, with setup times of 100 ms and holding times as short as a few seconds to a minute. A major management challenge is designing a provisioning protocol for the dynamic...
In this paper, we present a single-carrier (SC) waveform with smart antenna and frequency domain equalization (FDE) technologies to effectively combat both urban multipath and radio interference. It is designed to be power efficient, spectrally efficient, high quality, and capable of operating at vehicular speeds with long range. It can work on a small form factor device to support transport of streaming...
There is a dramatic increase in standards work due to the progress of cognitive radio technology and changes in spectrum allocation dictated by the Federal Communications Commission (FCC). The IEEE Standards Coordinating Committee 41 (SCC41) represents standards projects in the areas of dynamic spectrum access, cognitive radio, interference management, coordination of wireless systems, advanced spectrum...
A blueprint for an experimental low-power communications device (wireless mote) suitable for ad-hoc and networking applications is presented. The proposed device implements a random access packet-based communications protocol that exploits a special packet structure which is composed of separate header and payload portions. To enable robust packet detection, the headers consist of a preassigned spreading...
We propose a method to track an unknown and variable number of targets without assuming the knowledge of the locations of the sensor nodes in the network. Then, the multitarget tracking and the localization of sensor nodes is performed jointly. As low-power consumption is a requirement in sensor networks, a collaborative estimation scheme is presented, where only a small set of sensors are active...
In this paper, we investigate the performance of the sub-carrier multiplexed-free space optics (SCM-FSO) for transmitting code division multiple access (CDMA) signals in terms of carrier-to-noise-plus-interference ratio (CNIR) and bit error rate (BER), under Gamma-Gamma turbulent FSO channel. We propose an analytical model for optimization of the SCM-FSO link and a closed-form BER expression taking...
Communications and processing for Net-Centric Airborne Networks may become more vulnerable as additional nodes and entities are added to the networks. Accordingly, Information Assurance must provide greater protections in the face of these wider vulnerabilities. The capabilities of legacy systems still provide a basis for IA, but new operating modes mean that new capabilities are needed to mitigate...
In this paper, we propose a novel sidelobe suppression approach for cognitive radio systems employing orthogonal frequency division multiplexing (OFDM) transmission. OFDM is a promising solution for future overlay wireless access due to its high data rate and flexibility. However, OFDM and its variants employ sinc-type pulses in representing the symbols transmitted over all subcarriers during one...
This paper considers a synchronous DS-CDMA system where channel state information at the base station is acquired via uplink training and channel feedback is used to provide the terminals with the optimal uplink signatures. We examine the tradeoffs involved in the proportioning of a resource block between training, data, and feedback symbols, with linear (matched filter and minimum mean-square error)...
This paper investigates the issue of resource allocation in multicarrier wireless networks, where users have a choice between multiple service providers. We investigate the feasibility of modeling the allocation problem as a probabilistic voting game. In other words, competing transmitters are modeled as candidates in an election, while the receivers form the electorate. The specific example analyzed...
This work proposes a method for localizing a single near-field source using a moving array. Using a phase correction factor calculated from two sequences of selected data snapshots, we extend the array aperture and compute the initial estimates of the source's bearing and range from the extended data sets. With the initial estimates of bearing and range we construct a phase difference factor to modify...
The mobile user objective system (MUOS) is a geo-satellite communications system derived from the terrestrial cellular WCDMA air interface. WCDMA power control with the long geo-satellite round trip time presents substantial challenges. This paper describes the Point-to-Point power control system with simulation results using time-varying channel models specified by the MUOS program office.
The majority of prior work in signal-to-noise ratio estimation makes fairly strong assumptions concerning a priori knowledge of the channel state and signal. For instance, many of these estimators assume knowledge of the modulation scheme of the signal, or even complete knowledge of the transmitted set of modulated data symbols (typically through the use of training sequences). Even more universally,...
We present a new collision free medium access control algorithm suitable for large ad-hoc network. The algorithm is iterative and distributed, i.e., each node acquires, stores and processes only information related to its neighbors. Given a random set of nodes requesting access to the common medium during each timeslot, the algorithm attempts to allow the largest fraction of nodes to do so, subject...
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...
In crypto-partitioned networks classified clear text enclaves (i.e., red enclaves) are interconnected over an enciphered unclassified transit network (i.e., black network) via IPSEC tunnels. Thus, packets are encrypted before they are allowed to cross from red networks to a shared black network. Currently, there is no solution that can provide efficient end-to-end IntServ QoS signaling across crypto-partitioned...
Traditionally, digital signal processing (DSP) is performed using fixed-point or integer arithmetic. The algorithm is carefully mapped into a limited dynamic range, and scaled through each function in the datapath. This requires numerous rounding and saturation steps, and can adversely affect the algorithm performance. Use of floating-point arithmetic provides a large dynamic range and greatly simplifies...
One of the fundamental differences between the terrestrial radio frequency (RF) signal and underwater acoustic signal is long propagation delay. This paper is focused on a scheduling scheme for regional data collection in underwater acoustic sensor networks. Long propagation delay of the acoustic signal causes a serious problem for transmission scheduling. In this paper, we propose an efficient transmission...
Current DoD requirements call for a single enterprise terminal supporting up to 48/96 (threshold/objective) transmit and 56/112 (threshold/objective) receive communications carriers, not considering future expansion. The number of links supported by an enterprise terminal dictates aggregate servicing capacity. A single teleport/standardized tactical entry point (STEP) site can consist of five or more...
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