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- Mazloum, Nafiseh Seyed, et al.
(författare)
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Improving practical sensitivity of energy optimized wake-up receivers : Proof of concept in 65nm CMOS
- 2016
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Ingår i: IEEE Sensors Journal. - 1530-437X. ; PP:99, s. 8158-8166
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Tidskriftsartikel (refereegranskat)abstract
- We present a high performance low-power digital base-band architecture, specially designed for an energy optimized duty-cycled wake-up receiver scheme. Based on a careful wake-up beacon design, a structured wake-up beacon detection technique leads to an architecture that compensates for the implementation loss of a low-power wake-up receiver front-end at low energy and area costs. Design parameters are selected by energy optimization and the architecture is easily scalable to support various network sizes. Fabricated in 65nm CMOS, the digital base-band consumes 0:9μW (VDD = 0:37V) in sub-threshold operation at 250kbps, with appropriate 97% wake-up beacon detection and 0:04% false alarm probabilities. The circuit is fully functional at a minimum VDD of 0:23V at fmax = 5kHz and 0:018μW power consumption. Based on these results we show that our digital base-band can be used as a companion to compensate for front-end implementation losses resulting from the limited wake-up receiver power budget at a negligible cost. This implies an improvement of the practical sensitivity of the wake-up receiver, compared to what is traditionally reported.
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| 2. |
- Seyed Mazloum, Nafiseh, et al.
(författare)
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Comparing Analog Front-Ends for Duty-Cycled Wake-Up Receivers in Wireless Sensor Networks
- 2016
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Ingår i: IEEE Sensors Journal. - 1558-1748. ; 16:18, s. 7016-7021
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Tidskriftsartikel (refereegranskat)abstract
- Using ultralow-power wake-up receivers (WRxs) can reduce idle listening energy cost in wireless sensor networks with low traffic intensity. This has led to many WRx analog front-end (AFE) designs presented in literature, with a large variety of trade-offs between the sensitivity, the data rate, and the power consumption. Energy consumed during wake-up in a network depends on many parameters and without a unified energy analysis, we cannot compare performance of different AFEs. We present an analysis of duty-cycled WRx schemes which provides a simple tool for such a comparison based on the energy consumed in an entire single-hop network during a wake-up. The simplicity is largely due to the fact that all network and communication parameter settings can be condensed into a single scenario constant. This tool allows us to both compare AFEs for specific scenarios and draw more general conclusions about AFE performance across all scenarios.
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| 3. |
- Seyed Mazloum, Nafiseh
(författare)
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Duty-cycled Wake-up Schemes for Ultra-low Power Wireless Communications
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In sensor network applications with low traffic intensity, idle channel listening is one of the main sources of energy waste.The use of a dedicated low-power wake-up receiver (WRx) which utilizes duty-cycled channel listening can significantlyreduce idle listening energy cost. In this thesis such a scheme is introduced and it is called DCW-MAC, an acronym forduty-cycled wake-up receiver based medium access control.We develop the concept in several steps, starting with an investigation into the properties of these schemes under idealizedconditions. This analysis show that DCW-MAC has the potential to significantly reduce energy costs, compared to twoestablished reference schemes based only on low-power wake up receivers or duty-cycled listening. Findings motivatefurther investigations and more detailed analysis of energy consumption. We do this in two separate steps, first concentratingon the energy required to transmit wake-up beacons and later include all energy costs in the analysis. The more completeanalysis makes it possible to optimize wake-up beacons and other DCW-MAC parameters, such as sleep and listen intervals,for minimal energy consumption. This shows how characteristics of the wake-up receiver influence how much, and if, energycan be saved and what the resulting average communication delays are. Being an analysis based on closed form expressions,rather than simulations, we can derive and verify good approximations of optimal energy consumption and resulting averagedelays, making it possible to quickly evaluate how a different wake-up receiver characteristic influences what is possible toachieve in different scenarios.In addition to the direct optimizations of the DCW-MAC scheme, we also provide a proof-of-concept in 65 nm CMOS,showing that the digital base-band needed to implement DCW-MAC has negligible energy consumption compared to manylow-power analog front-ends in literature. We also propose a a simple frame-work for comparing the relative merits ofanalog front-ends for wake-up receivers, where we use the experiences gained about DCW-MAC energy consumption toprovide a simple relation between wake-up receiver/analog front-end properties and energy consumption for wide ranges ofscenario parameters. Using this tool it is possible to compare analog front-ends used in duty-cycled wake-up schemes, evenif they are originally designed for different scenarios.In all, the thesis presents a new wake-up receiver scheme for low-power wireless sensor networks and provide a comprehensiveanalysis of many of its important properties.
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