178,196 research outputs found
The Choice of Codes Used by Two Announcers of Dj Fm and Ss Fm Radio Stations in Their Advertisements
This thesis is a study of the choice of codes used by the announcers of DJ FM and SS FM radios in their advertisements, consisting of twenty advertisements from both radios. I applied some theories of codes from Wardaugh (2006), Stockwell (2002), and Holmes (2001) as my main theories. Also, I used the theory of Age and Linguistic choice from Coulmas (2005), and Marketing and Language Choice from Victor (2007) as my supporting theories. The subjects are two announcers of DJ FM and SS FM radios which are in the phase of young adulthood. Furthermore, I found that the announcers from both radio stations used Standard Indonesia as their main code. The conclusion is the target audience of DJ FM and SS FM did not influence the way the announcers chose their codes
Spatial-Spectral Joint Detection for Wideband Spectrum Sensing in Cognitive Radio Networks
Spectrum sensing is an essential functionality that enables cognitive radios
to detect spectral holes and opportunistically use under-utilized frequency
bands without causing harmful interference to primary networks. Since
individual cognitive radios might not be able to reliably detect weak primary
signals due to channel fading/shadowing, this paper proposes a cooperative
wideband spectrum sensing scheme, referred to as spatial-spectral joint
detection, which is based on a linear combination of the local statistics from
spatially distributed multiple cognitive radios. The cooperative sensing
problem is formulated into an optimization problem, for which suboptimal but
efficient solutions can be obtained through mathematical transformation under
practical conditions.Comment: To appear in the Proceedings of the 2008 IEEE International
Conference on Acoustics, Speech and Signal Processing, Las Vegas, NV, March
30-April 4, 200
Providing End-to-End Delay Guarantees for Multi-hop Wireless Sensor Networks over Unreliable Channels
Wireless sensor networks have been increasingly used for real-time
surveillance over large areas. In such applications, it is important to support
end-to-end delay constraints for packet deliveries even when the corresponding
flows require multi-hop transmissions. In addition to delay constraints, each
flow of real-time surveillance may require some guarantees on throughput of
packets that meet the delay constraints. Further, as wireless sensor networks
are usually deployed in challenging environments, it is important to
specifically consider the effects of unreliable wireless transmissions.
In this paper, we study the problem of providing end-to-end delay guarantees
for multi-hop wireless networks. We propose a model that jointly considers the
end-to-end delay constraints and throughput requirements of flows, the need for
multi-hop transmissions, and the unreliable nature of wireless transmissions.
We develop a framework for designing feasibility-optimal policies. We then
demonstrate the utility of this framework by considering two types of systems:
one where sensors are equipped with full-duplex radios, and the other where
sensors are equipped with half-duplex radios. When sensors are equipped with
full-duplex radios, we propose an online distributed scheduling policy and
proves the policy is feasibility-optimal. We also provide a heuristic for
systems where sensors are equipped with half-duplex radios. We show that this
heuristic is still feasibility-optimal for some topologies
Design Considerations of a Sub-50 {\mu}W Receiver Front-end for Implantable Devices in MedRadio Band
Emerging health-monitor applications, such as information transmission
through multi-channel neural implants, image and video communication from
inside the body etc., calls for ultra-low active power (<50W) high
data-rate, energy-scalable, highly energy-efficient (pJ/bit) radios. Previous
literature has strongly focused on low average power duty-cycled radios or low
power but low-date radios. In this paper, we investigate power performance
trade-off of each front-end component in a conventional radio including active
matching, down-conversion and RF/IF amplification and prioritize them based on
highest performance/energy metric. The analysis reveals 50 active
matching and RF gain is prohibitive for 50W power-budget. A mixer-first
architecture with an N-path mixer and a self-biased inverter based baseband
LNA, designed in TSMC 65nm technology show that sub 50W performance can
be achieved up to 10Mbps (< 5pJ/b) with OOK modulation.Comment: Accepted to appear on International Conference on VLSI Design 2018
(VLSID
Efficient multi-standard cognitive radios on FPGAs
Cognitive radios that support multiple standards and modify operation depending on environmental conditions are becoming more important as the demand for higher bandwidth and efficient spectrum use increases. Traditional implementations in custom ASICs cannot support such flexibility, with standards changing at a faster pace, while software baseband implementations fail to achieve the performance required. Hence, FPGAs offer an ideal platform bringing together flexibility, performance, and efficiency. This work explores the possible techniques for designing multi-standard radios on FPGAs, and explores how partial reconfiguration can be leveraged in a way that is amenable for domain experts with minimal FPGA knowledge
How Push-To-Talk Makes Talk Less Pushy
This paper presents an exploratory study of college-age students using
two-way, push-to-talk cellular radios. We describe the observed and reported
use of cellular radio by the participants. We discuss how the half-duplex,
lightweight cellular radio communication was associated with reduced
interactional commitment, which meant the cellular radios could be used for a
wide range of conversation styles. One such style, intermittent conversation,
is characterized by response delays. Intermittent conversation is surprising in
an audio medium, since it is typically associated with textual media such as
instant messaging. We present design implications of our findings.Comment: 10 page
A Novel Algorithm for Cooperative Distributed Sequential Spectrum Sensing in Cognitive Radio
This paper considers cooperative spectrum sensing in Cognitive Radios. In our
previous work we have developed DualSPRT, a distributed algorithm for
cooperative spectrum sensing using Sequential Probability Ratio Test (SPRT) at
the Cognitive Radios as well as at the fusion center. This algorithm works
well, but is not optimal. In this paper we propose an improved algorithm-
SPRT-CSPRT, which is motivated from Cumulative Sum Procedures (CUSUM). We
analyse it theoretically. We also modify this algorithm to handle uncertainties
in SNR's and fading.Comment: This paper has been withdrawn by the author due to the submission of
detailed journal version of the same paper, to arXi
Joint Ultra-wideband and Signal Strength-based Through-building Tracking for Tactical Operations
Accurate device free localization (DFL) based on received signal strength
(RSS) measurements requires placement of radio transceivers on all sides of the
target area. Accuracy degrades dramatically if sensors do not surround the
area. However, law enforcement officers sometimes face situations where it is
not possible or practical to place sensors on all sides of the target room or
building. For example, for an armed subject barricaded in a motel room, police
may be able to place sensors in adjacent rooms, but not in front of the room,
where the subject would see them. In this paper, we show that using two
ultra-wideband (UWB) impulse radios, in addition to multiple RSS sensors,
improves the localization accuracy, particularly on the axis where no sensors
are placed (which we call the x-axis). We introduce three methods for combining
the RSS and UWB data. By using UWB radios together with RSS sensors, it is
still possible to localize a person through walls even when the devices are
placed only on two sides of the target area. Including the data from the UWB
radios can reduce the localization area of uncertainty by more than 60%.Comment: 9 pages, conference submissio
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