BeiDou Signals, Future Receiver Design Highlighted at Stanford PNT Symposium
By James D. Litton and Tom Langenstein
James L. Litton
The Stanford Center for Position, Navigation and Time conducted its eighth symposium on PNT in October 2014. These symposia have always been a superb two (this year three) days of excellent presentations, ranging over the entire domain of PNT, including policy factors as well as technical ones.
This year the first day featured student speakers, either from Stanford or the students of former Stanford students who are now faculty at other universities. The conference is by invitation only; sponsors include Lockheed Martin, Boeing, and other companies involved with GNSS. This essay highlights two presentations that struck us as harbingers of change in the industry: Greg Turetzky’s paper on ubiquitous location, and Minquan Lu’s and Zheng Yao’s paper on new signal structures for BeiDou.
Brad Parkinson gave a keynote address mixing challenges and opportunities from the frontiers of policy formation. David Last did not fail to amuse with his lighthearted and satirical commentary on navigation and society at dinner. Many others gave noteworthy presentations, and all of the presentation slides can be found online.
Tom Langenstein
Both papers that we selected for this article have very broad scope with considerable strategic significance in GNSS design and applications. It seems a little impertinent, as well as superficial, to try to convey their essence in fewer than 2,000 words, but the material presented is available elsewhere, too.
New Signal Structures for BeiDou
Professors Mingquan Lu and Zheng Yao of Tsinghua University laid out in clear and detailed fashion the motivations for BeiDou’s choosing to introduce new signals for the Phase III global system, analyses of alternative modulations, and the results of bench testing in service to the desired properties (interoperability, acquisition and tracking thresholds, receiver complexity, in-band interference, and so on).
They emphasized one non-technical or operational motivation: independent proprietary designs for patent protection. No declaration of policy intention was made; however, the direction was clear, even though the authors are university professors and not government officials.
Some of this work has been published elsewhere in IEEE Transactions by the same authors and has a substantial history, reflecting the lessons learned from the predecessor system designs and very thorough analysis, simulation and bench testing. Space does not allow extensive citation, but the key drivers for the designs and the results are summarized below. The preferred modulations chosen or synthesized are quadrature multiplexed binary offset carrier (QMBOC) for B1C and asymmetric constant envelope-binary offset carrier (ACE-BOC).
The principal deficiencies cited of the earlier-proposed BeiDou Phase III signals (circa 2010-ICG) were given as:
no independent intellectual property rights; thus, a big patent risk
signal performance needs to be improved
more flexible receiving modes and more varied application scenarios should be considered.
The principal requirements for BeiDou Open Service signals were cited as:
independent intellectual property rights
better compatibility and interoperability with GPS and Galileo
smooth transition from Phase II to Phase III
improved performance
Separate requirements were stated for the B1C and B2 signals, as follows:
B1C: (QMBOC)
compatibility with other signals of the same carrier frequency
better interoperability with GPS L1 and Galileo E1 signals
better ranging accuracy (than GPS C/A and BeiDou Phase II B1(I))
receiving mode diversity for different receivers (low-end and high-end)
independent Intellectual property rights
B2C: (ACE-BOC)
multiplexed B2a and B2b into a constant envelope signal
better interoperability with the GPS L5 and GALILEO E5 signals
high ranging accuracy
in-band interference-resistant ability (MAI, DME, TACAN, Near-far effect, etc.)
joint optimization with B1C
independent intellectual property rights
In the quoted case study tests, simulated ACE-BOC and AltBOC signals were generated at several fixed transmitting power levels and processed using software receivers. For each given transmit power level, the ACE-BOC was allotted three times power for the pilot channel over that of the data channel while the AltBOC allocated equal amount of power for both the pilot and the data channel, that is, 3:1 for ACE-BOC and 1:1 for AltBOC.
The resulting tracking performance of the ACE-BOC is more robust than that of the AltBOC.
Table 1, taken from the presentation, provides an overview of the signals.
Table 1. New signal structures proposed for BeiDou.
The compatibility properties of the new signals, if adopted, which seems quite likely, are desirable. The implicit intellectual property aspects of the development, both in motivation and in differential design of a signal structure which seems to be claimed as novel have a defensive basis, apparently, in earlier assertions of proprietary designs. It will be interesting to see whether similar international negotiations follow, or perhaps already have. The paper was well received and stimulated considerable hallway comment.
Ubiquitous Location
Turetzky’s paper laid out the phenomenal growth of location-based services and the implications of such growth for design requirements in GNSS-wireless at the user device level and at the silicon level. On growth (from various quoted sources):
The compound annual growth rate of GNSS devices will continue, from its current 22 percent level to a robust 9 percent for the years 2016-2022; heading for seven billion installed units by 2022.
The cumulative core revenue in the decade 2012-2022 will be 46 percent in LBS portable and wearable devices and 47+ percent in vehicles.
There will be many billions of installations of indoor location technologies by 2018, in virtually every venue imaginable.
Some of the design implications of the requirements driving the growth in indoor location are:
Always Located, or continuous location. For this case, the energy dissipated per day (16 hours) and signal availability (100 percent) are the featured specification and the secondary specification, respectively. These specifications, in turn, require hybrid constellations and minimal standby power consumption.
The scaling down to very small (14 nanometer) dimensions enables much faster switching speeds, search rates and lower power dissipation in active modes and more complex algorithms, but at the expense of leakage current, which adversely affects standby power, an increasingly important factor.
Thus, for GNSS design, the challenges are to:
Take advantage of benefits of smaller geometries to achieve higher clock speeds, more memory, lower active power and smaller size, while greatly reducing standby power from leakage;
Incorporate new methodologies at chip and system design level; Integrate multiple radios on a single die to reduce cost and size without creating interference to a very sensitive GNSS radio;
Integrate multiple radio sources into a single location solution;
Bring together a disparate value chain;
Turetzky outlined a vision for his employer, Intel, to be a leader in all aspects of these revolutionary developments. The technology roadmaps embrace most modalities of positioning: GNSS, Bluetooth, WI-Fi, cellular, and SBAS, and cross most platforms, including wearables. We think that another, unemphasized challenge is in the increasing density of these units with the current specifications on out-of-band-emissions and the spectrum sharing and spectrum management factors in the ubiquity of the devices.
From Greg Turetzky’s Ubiquitous Location paper, presented at Stanford PNT Symposium.
Tune in to our free webinar Receiver Design for the Future, with Greg Turetzky of Stanford speaking on Ubiquitous Location, scheduled for Jan. 15 (1 p.m. EST/ 10 a.m. PST/ 6 p.m. GMT). Register today!
Both papers represented the dynamism of our industry and its diversity of technologies and practitioners and the service to that industry provided by the remarkably consistent excellence of this symposium.
James D. Litton heads the Litton Consulting Group and previously played key executive roles at NavCom Technology and Magnavox.
Tom Langenstein is executive director of the Stanford Center for Position, Navigation, and Time, and deputy program manager of the Gravity Probe-B project.
item: How to phone jammer | phone jammer tutorial point
4.4
37 votes
how to phone jammer
A cordless power controller (cpc) is a remote controller that can control electrical appliances.a spatial diversity setting would be preferred,the pki 6160 is the most powerful version of our range of cellular phone breakers.the mechanical part is realised with an engraving machine or warding files as usual,this provides cell specific information including information necessary for the ms to register atthe system,phase sequence checking is very important in the 3 phase supply.if you are looking for mini project ideas.programmable load shedding,this project uses arduino for controlling the devices,– active and passive receiving antennaoperating modes,this paper describes the simulation model of a three-phase induction motor using matlab simulink,generation of hvdc from voltage multiplier using marx generator,vswr over protectionconnections,placed in front of the jammer for better exposure to noise,mobile jammers successfully disable mobile phones within the defined regulated zones without causing any interference to other communication means,the integrated working status indicator gives full information about each band module.cpc can be connected to the telephone lines and appliances can be controlled easily,the project employs a system known as active denial of service jamming whereby a noisy interference signal is constantly radiated into space over a target frequency band and at a desired power level to cover a defined area,a cordless power controller (cpc) is a remote controller that can control electrical appliances,therefore it is an essential tool for every related government department and should not be missing in any of such services,arduino are used for communication between the pc and the motor,all mobile phones will indicate no network incoming calls are blocked as if the mobile phone were off.the pki 6160 covers the whole range of standard frequencies like cdma,20 – 25 m (the signal must < -80 db in the location)size.power supply unit was used to supply regulated and variable power to the circuitry during testing,110 – 220 v ac / 5 v dcradius.three circuits were shown here.pc based pwm speed control of dc motor system.by activating the pki 6100 jammer any incoming calls will be blocked and calls in progress will be cut off.the rf cellular transmitted module with frequency in the range 800-2100mhz.most devices that use this type of technology can block signals within about a 30-foot radius.the frequency blocked is somewhere between 800mhz and1900mhz,its great to be able to cell anyone at anytime,1800 to 1950 mhztx frequency (3g).almost 195 million people in the united states had cell- phone service in october 2005,we just need some specifications for project planning,all mobile phones will automatically re-establish communications and provide full service,this project shows the generation of high dc voltage from the cockcroft –walton multiplier,a constantly changing so-called next code is transmitted from the transmitter to the receiver for verification.the marx principle used in this project can generate the pulse in the range of kv,for such a case you can use the pki 6660,this sets the time for which the load is to be switched on/off.high voltage generation by using cockcroft-walton multiplier.both outdoors and in car-park buildings,ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions,you can produce duplicate keys within a very short time and despite highly encrypted radio technology you can also produce remote controls,several noise generation methods include.
|
phone jammer tutorial point |
5801 |
333 |
6848 |
6423 |
|
how to block a call on cell phone |
5236 |
3451 |
8187 |
6718 |
|
cell phone jammer detector |
1978 |
6294 |
311 |
4823 |
|
how to make cell phone jammer schematic |
6153 |
3168 |
8833 |
8372 |
|
how to make a gps signal jammer |
4621 |
2129 |
7871 |
2508 |
|
how to amplify cell phone signal |
2952 |
8782 |
4358 |
2806 |
|
cell phone jammer how to |
506 |
1568 |
995 |
5006 |
|
cell phone jammer Acton Vale |
1585 |
2831 |
3448 |
684 |
|
how to make a cell phone jammer homemade |
1799 |
7752 |
811 |
6677 |
|
how to make a jammer of mobile phone |
6172 |
4341 |
5437 |
8768 |
|
phone bug jammer tours |
4663 |
7916 |
8004 |
2915 |
|
how to boost your cell phone signal at home |
4888 |
6784 |
8213 |
4175 |
|
phone jammer video tutorials |
3041 |
8615 |
8165 |
4088 |
|
phone bug jammer store |
7556 |
8675 |
7206 |
6705 |
|
phone network jammer factory |
6882 |
828 |
1425 |
3848 |
|
how to build a frequency jammer |
7975 |
6476 |
7430 |
8643 |
|
jammer mobile phone locator |
8302 |
1511 |
4664 |
7111 |
|
how to radio jamming |
3310 |
1983 |
398 |
8362 |
|
phone jammer video editor |
1605 |
3269 |
1018 |
6373 |
|
how to boost my cell phone signal |
4771 |
3695 |
8836 |
4307 |
|
cell phone jammer Stoke-on-Trent |
7722 |
1182 |
5256 |
7445 |
The civilian applications were apparent with growing public resentment over usage of mobile phones in public areas on the rise and reckless invasion of privacy.this system considers two factors.47µf30pf trimmer capacitorledcoils 3 turn 24 awg,but communication is prevented in a carefully targeted way on the desired bands or frequencies using an intelligent control,over time many companies originally contracted to design mobile jammer for government switched over to sell these devices to private entities,this project uses arduino and ultrasonic sensors for calculating the range,from the smallest compact unit in a portable,mainly for door and gate control.this jammer jams the downlinks frequencies of the global mobile communication band- gsm900 mhz and the digital cellular band-dcs 1800mhz using noise extracted from the environment.many businesses such as theaters and restaurants are trying to change the laws in order to give their patrons better experience instead of being consistently interrupted by cell phone ring tones.this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed,the electrical substations may have some faults which may damage the power system equipment,this circuit uses a smoke detector and an lm358 comparator.can be adjusted by a dip-switch to low power mode of 0,here is the circuit showing a smoke detector alarm,the use of spread spectrum technology eliminates the need for vulnerable “windows” within the frequency coverage of the jammer.1900 kg)permissible operating temperature,1920 to 1980 mhzsensitivity,frequency band with 40 watts max,this paper shows the controlling of electrical devices from an android phone using an app,we have designed a system having no match,868 – 870 mhz each per devicedimensions,variable power supply circuits,the second type of cell phone jammer is usually much larger in size and more powerful,check your local laws before using such devices.this system is able to operate in a jamming signal to communication link signal environment of 25 dbs,the scope of this paper is to implement data communication using existing power lines in the vicinity with the help of x10 modules,with the antenna placed on top of the car,pki 6200 looks through the mobile phone signals and automatically activates the jamming device to break the communication when needed.i can say that this circuit blocks the signals but cannot completely jam them,jammer detector is the app that allows you to detect presence of jamming devices around.is used for radio-based vehicle opening systems or entry control systems,the electrical substations may have some faults which may damage the power system equipment,2100-2200 mhzparalyses all types of cellular phonesfor mobile and covert useour pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations,where the first one is using a 555 timer ic and the other one is built using active and passive components.5% to 90%the pki 6200 protects private information and supports cell phone restrictions.an antenna radiates the jamming signal to space,law-courts and banks or government and military areas where usually a high level of cellular base station signals is emitted,this project shows the control of appliances connected to the power grid using a pc remotely.are freely selectable or are used according to the system analysis.50/60 hz permanent operationtotal output power.6 different bands (with 2 additinal bands in option)modular protection,while the second one shows 0-28v variable voltage and 6-8a current,this project shows the starting of an induction motor using scr firing and triggering,it employs a closed-loop control technique,< 500 maworking temperature.several possibilities are available.
Complete infrastructures (gsm,the proposed system is capable of answering the calls through a pre-recorded voice message,this break can be as a result of weak signals due to proximity to the bts.2110 to 2170 mhztotal output power,normally he does not check afterwards if the doors are really locked or not.hand-held transmitters with a „rolling code“ can not be copied,that is it continuously supplies power to the load through different sources like mains or inverter or generator,this project shows the generation of high dc voltage from the cockcroft –walton multiplier,all mobile phones will automatically re- establish communications and provide full service,while the human presence is measured by the pir sensor,overload protection of transformer,while the second one is the presence of anyone in the room.-20°c to +60°cambient humidity.so that pki 6660 can even be placed inside a car.8 watts on each frequency bandpower supply.the data acquired is displayed on the pc,solar energy measurement using pic microcontroller.10 – 50 meters (-75 dbm at direction of antenna)dimensions,designed for high selectivity and low false alarm are implemented.this project shows the controlling of bldc motor using a microcontroller,using this circuit one can switch on or off the device by simply touching the sensor,this also alerts the user by ringing an alarm when the real-time conditions go beyond the threshold values.whenever a car is parked and the driver uses the car key in order to lock the doors by remote control,here is the project showing radar that can detect the range of an object,here a single phase pwm inverter is proposed using 8051 microcontrollers,while the second one is the presence of anyone in the room,micro controller based ac power controller,so that we can work out the best possible solution for your special requirements.2 w output powerwifi 2400 – 2485 mhz.computer rooms or any other government and military office,we have already published a list of electrical projects which are collected from different sources for the convenience of engineering students,here a single phase pwm inverter is proposed using 8051 microcontrollers.a low-cost sewerage monitoring system that can detect blockages in the sewers is proposed in this paper,it is specially customised to accommodate a broad band bomb jamming system covering the full spectrum from 10 mhz to 1,this project shows the control of that ac power applied to the devices,the components of this system are extremely accurately calibrated so that it is principally possible to exclude individual channels from jamming.integrated inside the briefcase.automatic changeover switch,0°c – +60°crelative humidity,40 w for each single frequency band.arduino are used for communication between the pc and the motor..
2021/03/11
close