ABSTRACT Impulse radio ultra-wideband (IR-UWB) is being employed in several IEEE standards for Wi... more ABSTRACT Impulse radio ultra-wideband (IR-UWB) is being employed in several IEEE standards for Wireless Sensor Network (WSN). This paper presents a battery model for small form factor, zinc-air button cell batteries with high energy density but also high internal impedance. Their usage in small form factor IR-UWB radios, requires accurate modeling to enable proper power management system design, avoiding system failure due to excessive supply voltage variation. In preamble synchronization phase all receiver blocks are used continuously, causing a current peak. The required battery model consists of seven resistor-capacitor (RC) sections.
Performance analysis of a system employing coordinate interleaving and constellation rotation in ... more Performance analysis of a system employing coordinate interleaving and constellation rotation in frequency-selective fading channels is presented. The achievable performance for L-branch microdiversity using maximum ratio combining (MRC) receiver is analyzed and an upper bound on the average probability of bit error (Pb) is presented. Exact closed form expressions for pairwise error probability (PEP) are derived for single-symbol transmission in
2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013
ABSTRACT Impulse radio ultra-wideband (IR-UWB) is being employed in several IEEE standards for Wi... more ABSTRACT Impulse radio ultra-wideband (IR-UWB) is being employed in several IEEE standards for Wireless Sensor Network (WSN). This paper presents a battery model for small form factor, zinc-air button cell batteries with high energy density but also high internal impedance. Their usage in small form factor IR-UWB radios, requires accurate modeling to enable proper power management system design, avoiding system failure due to excessive supply voltage variation. In preamble synchronization phase all receiver blocks are used continuously, causing a current peak. The required battery model consists of seven resistor-capacitor (RC) sections.
IEEE journal of biomedical and health informatics, Jan 19, 2015
This paper presents an ultra-low power wireless transceiver specialized for but not limited to me... more This paper presents an ultra-low power wireless transceiver specialized for but not limited to medical implantable applications. It operates at the 402-405MHz Medical Implant Communication Service (MICS) band and also supports the 420-450MHz Industrial, Scientific, and Medical (ISM) band. Being IEEE 802.15.6 standard compliant with additional proprietary modes, this highly configurable transceiver achieves date rates from 11kbps to 4.5Mbps, which covers the requirements of conventional implantable applications. The phase-locked loop (PLL)-based transmitter architecture is adopted to support various modulation schemes with limited power budget. The zero-IF receiver has programmable gain and bandwidth to accommodate different operation modes. Fabricated in 40nm CMOS technology with 1V supply, this transceiver only consumes 1.78mW for transmission and 1.49mW for reception. The ultra-low power consumption together with the 15.6-compliant performance in term of modulation accuracy, sensi...
ABSTRACT This paper investigates the word length requirement of an analog-to-digital (ADC) conver... more ABSTRACT This paper investigates the word length requirement of an analog-to-digital (ADC) converter for coherent and non-coherent detection of On-Off Keying (OOK) schemes. The paper presents closed-form expressions for coherent and non-coherent detection in terms of bit error rate in the presence of quantization noise (QN) and additive white Gaussian noise (AWGN) channels. The analytical models show that for coherent as well as non-coherent demodulation of OOK schemes in AWGN channels and affected by QN, a 4-bit ADC is able to provide close to optimum performance. As OOK is popularly being employed in event-driven radios, we extend our analysis to these radios. Our analysis shows that for event-driven radios (also referred to as wakeup radios) a 4-bit ADC is able to provide close to optimum performance. Furthermore, in the paper all the analytical models are in close agreement with the simulation results.
2007 IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications, 2007
For design of reflectarray antennas, microstrip patches of varying length provide an attractive a... more For design of reflectarray antennas, microstrip patches of varying length provide an attractive alternative. In this paper the analysis, design and measurement of reflectarray antenna based on variable size at Ka-band is presented. The design procedure and critical parameters are discussed. For our analysis we employ a full wave solution, i.e., method of moment (MoM). This solution is made efficient using threads and parallel processing techniques. To validate our analysis, number of arrays are built and measured, showing a good agreement with the simulation results.
2011 XXXth URSI General Assembly and Scientific Symposium, 2011
Wakeup radios (also referred to as event-driven radios) is a paradigm for low-cost, low-energy id... more Wakeup radios (also referred to as event-driven radios) is a paradigm for low-cost, low-energy identification radios to assist the main radio for continuous channel monitoring without sacrificing the latency requirements. Wakeup radios show the potential to extend considerably the life-time of the main radios. In this paper, we present the design, and measurement results of an ultra low-power wakeup radio.
2012 19th IEEE Symposium on Communications and Vehicular Technology in the Benelux (SCVT), 2012
ABSTRACT This paper discusses the system level considerations of low-power receivers targeting bo... more ABSTRACT This paper discusses the system level considerations of low-power receivers targeting body area networks (BAN). Since low power consumption is of the utmost importance either OOK or FSK modulation have to be used. We compare the two modulation schemes and compare the system level design issues. Both receivers have a zero-IF architecture and thus have to deal with 1/f noise and DC offsets. The biggest challenge of envelope-detector based OOK receiver design is its poor interferer robustness; the signal-to-interferer-ratio need to be at least 16dB. Additionally the effect of limited ADC ENOB and OOK threshold level on the BER performance of OOK receivers are addressed. On the other hand FSK receivers require a stable local frequency reference which leads to higher power consumption. It can be concluded that in interferer-limited environments FSK receivers are the better choice. Whereas OOK receivers have a slightly lower power consumption.
ABSTRACT Impulse radio ultra-wideband (IR-UWB) is being employed in several IEEE standards for Wi... more ABSTRACT Impulse radio ultra-wideband (IR-UWB) is being employed in several IEEE standards for Wireless Sensor Network (WSN). This paper presents a battery model for small form factor, zinc-air button cell batteries with high energy density but also high internal impedance. Their usage in small form factor IR-UWB radios, requires accurate modeling to enable proper power management system design, avoiding system failure due to excessive supply voltage variation. In preamble synchronization phase all receiver blocks are used continuously, causing a current peak. The required battery model consists of seven resistor-capacitor (RC) sections.
Performance analysis of a system employing coordinate interleaving and constellation rotation in ... more Performance analysis of a system employing coordinate interleaving and constellation rotation in frequency-selective fading channels is presented. The achievable performance for L-branch microdiversity using maximum ratio combining (MRC) receiver is analyzed and an upper bound on the average probability of bit error (Pb) is presented. Exact closed form expressions for pairwise error probability (PEP) are derived for single-symbol transmission in
2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013
ABSTRACT Impulse radio ultra-wideband (IR-UWB) is being employed in several IEEE standards for Wi... more ABSTRACT Impulse radio ultra-wideband (IR-UWB) is being employed in several IEEE standards for Wireless Sensor Network (WSN). This paper presents a battery model for small form factor, zinc-air button cell batteries with high energy density but also high internal impedance. Their usage in small form factor IR-UWB radios, requires accurate modeling to enable proper power management system design, avoiding system failure due to excessive supply voltage variation. In preamble synchronization phase all receiver blocks are used continuously, causing a current peak. The required battery model consists of seven resistor-capacitor (RC) sections.
IEEE journal of biomedical and health informatics, Jan 19, 2015
This paper presents an ultra-low power wireless transceiver specialized for but not limited to me... more This paper presents an ultra-low power wireless transceiver specialized for but not limited to medical implantable applications. It operates at the 402-405MHz Medical Implant Communication Service (MICS) band and also supports the 420-450MHz Industrial, Scientific, and Medical (ISM) band. Being IEEE 802.15.6 standard compliant with additional proprietary modes, this highly configurable transceiver achieves date rates from 11kbps to 4.5Mbps, which covers the requirements of conventional implantable applications. The phase-locked loop (PLL)-based transmitter architecture is adopted to support various modulation schemes with limited power budget. The zero-IF receiver has programmable gain and bandwidth to accommodate different operation modes. Fabricated in 40nm CMOS technology with 1V supply, this transceiver only consumes 1.78mW for transmission and 1.49mW for reception. The ultra-low power consumption together with the 15.6-compliant performance in term of modulation accuracy, sensi...
ABSTRACT This paper investigates the word length requirement of an analog-to-digital (ADC) conver... more ABSTRACT This paper investigates the word length requirement of an analog-to-digital (ADC) converter for coherent and non-coherent detection of On-Off Keying (OOK) schemes. The paper presents closed-form expressions for coherent and non-coherent detection in terms of bit error rate in the presence of quantization noise (QN) and additive white Gaussian noise (AWGN) channels. The analytical models show that for coherent as well as non-coherent demodulation of OOK schemes in AWGN channels and affected by QN, a 4-bit ADC is able to provide close to optimum performance. As OOK is popularly being employed in event-driven radios, we extend our analysis to these radios. Our analysis shows that for event-driven radios (also referred to as wakeup radios) a 4-bit ADC is able to provide close to optimum performance. Furthermore, in the paper all the analytical models are in close agreement with the simulation results.
2007 IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications, 2007
For design of reflectarray antennas, microstrip patches of varying length provide an attractive a... more For design of reflectarray antennas, microstrip patches of varying length provide an attractive alternative. In this paper the analysis, design and measurement of reflectarray antenna based on variable size at Ka-band is presented. The design procedure and critical parameters are discussed. For our analysis we employ a full wave solution, i.e., method of moment (MoM). This solution is made efficient using threads and parallel processing techniques. To validate our analysis, number of arrays are built and measured, showing a good agreement with the simulation results.
2011 XXXth URSI General Assembly and Scientific Symposium, 2011
Wakeup radios (also referred to as event-driven radios) is a paradigm for low-cost, low-energy id... more Wakeup radios (also referred to as event-driven radios) is a paradigm for low-cost, low-energy identification radios to assist the main radio for continuous channel monitoring without sacrificing the latency requirements. Wakeup radios show the potential to extend considerably the life-time of the main radios. In this paper, we present the design, and measurement results of an ultra low-power wakeup radio.
2012 19th IEEE Symposium on Communications and Vehicular Technology in the Benelux (SCVT), 2012
ABSTRACT This paper discusses the system level considerations of low-power receivers targeting bo... more ABSTRACT This paper discusses the system level considerations of low-power receivers targeting body area networks (BAN). Since low power consumption is of the utmost importance either OOK or FSK modulation have to be used. We compare the two modulation schemes and compare the system level design issues. Both receivers have a zero-IF architecture and thus have to deal with 1/f noise and DC offsets. The biggest challenge of envelope-detector based OOK receiver design is its poor interferer robustness; the signal-to-interferer-ratio need to be at least 16dB. Additionally the effect of limited ADC ENOB and OOK threshold level on the BER performance of OOK receivers are addressed. On the other hand FSK receivers require a stable local frequency reference which leads to higher power consumption. It can be concluded that in interferer-limited environments FSK receivers are the better choice. Whereas OOK receivers have a slightly lower power consumption.
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