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Applications operating over airborne networks are known to perform quite sub-optimally. Transmission control protocol (TCP) based applications often experience very low data throughput, while the user datagram protocol (UDP) based applications suffer high packet loss as well as out-of-order delivery. This is due to the high bit error rate (BER) nature of the wireless links and the high mobility of...
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...
In this paper, we investigate a phase randomization technique in order to modify the coherence structure of a chaotically modulated signal. Phase randomization is shown to reduce the detectability of cyclostationary features, introduced by the constant chip rate of the chaotically modulated signal. The chaotic modulation scheme is based on the symbolic dynamics of a modified Bernoulli shift map and...
Owing to the extensive use of commercial wide-band SATCOM systems by the Department Of Navy (DON) and the Department of Defense (DOD) in general, designers and operators of such systems need to investigate and analyze the performance of a broad range of deployment options with respect to communications requirements under a given warfighting scenario, and show the effects of these alternatives on these...
Relay network is proposed as a means of improving the error performance and energy efficiency of the wireless networks. Inspired by the battery power efficiency (BPE) analysis in Duan et al. (2009), relay selection from the battery energy efficiency perspective turns out to be an interesting topic. Under the general network setup which integrates typical transmission and reception modules, we adopt...
This paper addresses the use of Resource ReSerVation Protocol-Aggregate (RSVP-AGG) at the tactical edge of the Air Force's Airborne Network (AN). Since the AN tactical edge can have different types of stub-networks accessing the AN (i.e., non-IP based legacy networks like Link 16, DiffServ based networks and IntServ based net-works), RSVP-AGG offers a common access approach regardless of the differences...
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...
The techniques of Terminal transmit adaptation are critical for achieving maximal channel throughput when the link loss exhibits large variation. In this paper, some technical issues regarding transmit power control and mode adaptation in satellite communication (SATCOM) systems are addressed. The transmit adaptation is explored in terms of optimizing the link availability. The analysis extends the...
In this paper, the expression for symbol error rate (SER) or BER of linear modulation in Rayleigh fading as a function of signal-to-noise ratio (SNR), modulation scheme and diversity order, is inverted, thereby giving SNR as a function of SER. The key is to represent the PDF (or MGF) by a Maclaurin series and discard all but the first one or two terms. For large SNRs, the first term in the series...
OFDM offers high bandwidth efficiency and low receiver equalization complexity; consequently OFDM is growing in popularity for adoption into robust high data rate services in wireless multipath channels. While these advantages have been proven for many wireless applications (including numerous IEEE wireless standards), one potential disadvantage of OFDM is that it exhibits high peak-to-average power...
Efficient use of spectrum requires an accurate determination of interference effects. In this paper, we introduce a radio to radio (R2R) factor that quantifies the interference effects of one radio waveform on another based on multiple waveform properties instead of solely on intermediate frequency (IF) signal power. The R2R factor is formulated as a dimensionless correction term in the victims communication...
The characteristics of a Mobile Tactical Network (MTN) operating in the VHF/UHF military radio band are investigated by applying an analytical model, radio measurement data and tactical mobility scenarios. The network node degree, connectivity, distribution of hop count, etc. are studied. Based on the identified properties, major networking schemes are evaluated for their applicability. Exploiting...
This paper presents simulation results which illustrate the performance of a fast frequency hopped - frequency division multiple access (FFH-FDMA) satellite communication system using a partial processing dehop-rehop transponder (DRT) under jamming. In the simulated system, convolutional coded symbols (using rates 1/2 or 1/4) are hopped with time diversity to enhance the anti-jamming (AJ) capacity...
In this paper, an analytical time-domain model is presented to analyze the radio over free space optical (RoFSO) systems under two turbulence channels, the log-normal and the exponential channel. This analytical model uses general cases of a dual-drive Mach-Zehnder modulator (DD-MZM) and photodetector (PD) for typical optical double sideband (ODSB) and single sideband (OSSB) signals under turbulence...
In this paper, we present three novel priority-based spectrum allocation techniques for enabling dynamic spectrum access (DSA) networking for non-contiguous orthogonal frequency division multiplexing (NC-OFDM) transmission. With each communication link in the network possessing a specified pair of bit error rate (BER) and throughput requirements for supporting a specific application, the proposed...
This paper presents a joint network management approach being studied for interfacing network management of different US future force networks. The approach attempts to pass information between the cipher text network managers of the army, the navy and the air force networks such that intelligent decisions can be made as traffic flows between these networks. As the first straw man approach, the paper...
The robustness to jamming signal is an important property for military communication systems. Some previous work has shown that the frequency domain code division multiplexing (CDM) efficiently rejects the interference. In general, however, the jamming signal has higher power than ordinary interference which leads to insufficient jamming rejection performance of these schemes. To mitigate this insufficiency,...
Multicarrier (MC) CDMA systems have been developed and rapidly gained popularity as they capitalize on both MCM (multicarrier modulation)'s resilience to multi-path fading and direct-sequence (DS) CDMA's simplicity in multi-access and synchronization design to mitigate both multiple access interference (MAI) and the inter-symbol interference (ISI) caused by time dispersive channels with the aid of...
In this paper, we explore the advantages of network coding and space-time coding in improving the performance of two-way relay channel communications where two terminals absent of direct link exchange information through a single relay in between. Network coding allows embracing interference from other terminals thereby turning it into a capacity boost. Application of space-time codes yields higher...
It is a well known fact that orthogonal frequency division multiplexing (OFDM) suffers from high peak to average power ratio (PAPR). The nonlinear distortion introduced by an OFDM signal through practical amplifiers can further degrade the system performance. Due to the limited bandwidth in the radio frequency spectrum, it is impossible that wireless communication systems can operate in an environment...
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