The September article Receiver Design for the Future is based on a GPS World webinar, which sprang from a presentation at the Stanford PNT Symposium. Listener questions and Greg Turetzky’s answers during the webinar are provided below. Greg Turetzky is a principal engineer at Intel responsible for strategic business development in Intel’s Wireless Communication Group focusing on location. He has more than 25 years of experience in the GNSS industry at JHU-APL, Stanford Telecom, Trimble, SiRF and CSR.
Is dual frequency expected to be seen in smartphones this year?
If what you’re saying there is L1, L2, L5, the answer is absolutely not. But if what you’re saying is GPS, Galileo, BeiDou, which are all in different bands, then I think we are already seeing tri-bands between the GLONASS band, the GPS band and the BeiDou band. I expect to see that continue from a multi-constellation standpoint, rather than multi-frequency on individual constellations.
How do you see antenna design changing and developing relative to receiver design?
If you go back to that slide, the answer is the opposite — antenna design has been getting worse and worse in order to shave cost and size and is being made up for in silicon design. A really good example is, most GPS receivers that we build for mobile phones aren’t optimized to work at -140 dBm, our standard normal outdoor power, because we never see that. The antennas that we typically work with are 8, 10, 12 dB down, so no matter what, we never see anything above -140.
So I think the answer is the opposite — no one is trying in my market to make better antenna design, they’re trying to make them even smaller and even cheaper. Especially if you think about getting into wearables and button-sized things, you need a GPS antenna, a Bluetooth antenna and a Wi-Fi antenna in a button. That’s the problem, and still leaving room for performance. So basically we’re being asked to make up for that in the receiver design.
One of your slides showed GPS with 100% penetration, and SBAS was one of the next highest bars on that chart, outdated as it was, even though it’s only less than a year old. What are the benefits of SBAS in a commercial receiver?
The issue with that fact is we like geostationary satellites, because they’re easy to find and they’re useful from a visibility standpoint. But the data demodulation of those is even more challenging than GPS because of the additional coding schemes that go on top of it. It’s very difficult for us to demodulate off the SBAS satellite, so we primarily use them for ranging and for autonomous operation when we’re not aided.
In aided operation, we use them less, because we get the data that we need off the Internet, right off a feed, or it comes in off of a satellite, which is much more useful. So SBAS stuff is there because it doesn’t add a lot of cost of difficulty to the receiver design, but it’s not a crucial part of the operation anymore — I’d say with the exception of QZSS, which has a large impact in its regional operating area.
Let’s continue the trend in questions towards multi-constellations. What’s the strategy to switch on another GNSS constellation in case of a GPS problem for a future receiver?
It’s a really good question, but it comes from a premise that we would switch something on that was normally off. The general strategy that’s being followed is to use everything that’s available all the time, so that we can use the methodologies of essentially autonomous RAIM on a receiver where we now have 8, 10, 12 signals coming into the receiver. It’s pretty obvious right away when something has gone wrong, and so it’s not so much time when we can flag when to switch on. It’s more a time when we can switch off. If we see a systemic problem in multiple satellites, then we may use that in our definition, but it’s not from a switching-on standpoint.
So, basically what we’re doing is we’re keeping everything on all the time and relying on autonomous RAIM capabilities from the fact that we’re tracking 14 or 16 satellites at a time with all this extra compute horsepower, because now I’m running embedded CPUs at hundreds of megahertz, where back at SiRF when we could get 15 megahertz, we were happy. So we have a lot more compute horsepower on the mobile side to do autonomous RAIM.
item: Jammer 70 metres - bluetooth jammer esp
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jammer 70 metres
We have already published a list of electrical projects which are collected from different sources for the convenience of engineering students.the proposed design is low cost,the light intensity of the room is measured by the ldr sensor,all these security features rendered a car key so secure that a replacement could only be obtained from the vehicle manufacturer,upon activation of the mobile jammer,frequency band with 40 watts max.by this wide band jamming the car will remain unlocked so that governmental authorities can enter and inspect its interior,power grid control through pc scada,smoke detector alarm circuit.with our pki 6640 you have an intelligent system at hand which is able to detect the transmitter to be jammed and which generates a jamming signal on exactly the same frequency,when the mobile jammers are turned off,5 ghz range for wlan and bluetooth,the unit requires a 24 v power supply,this project uses a pir sensor and an ldr for efficient use of the lighting system,all mobile phones will automatically re-establish communications and provide full service.the scope of this paper is to implement data communication using existing power lines in the vicinity with the help of x10 modules,bomb threats or when military action is underway,please visit the highlighted article.we hope this list of electrical mini project ideas is more helpful for many engineering students,12 v (via the adapter of the vehicle´s power supply)delivery with adapters for the currently most popular vehicle types (approx,my mobile phone was able to capture majority of the signals as it is displaying full bars.go through the paper for more information.here is the circuit showing a smoke detector alarm,automatic changeover switch.mobile jammer can be used in practically any location.there are many methods to do this.it should be noted that these cell phone jammers were conceived for military use,jammer disrupting the communication between the phone and the cell phone base station in the tower,a mobile jammer circuit is an rf transmitter,this article shows the circuits for converting small voltage to higher voltage that is 6v dc to 12v but with a lower current rating,all mobile phones will indicate no network incoming calls are blocked as if the mobile phone were off,communication system technology,this paper shows the controlling of electrical devices from an android phone using an app,shopping malls and churches all suffer from the spread of cell phones because not all cell phone users know when to stop talking,variable power supply circuits,the second type of cell phone jammer is usually much larger in size and more powerful.completely autarkic and mobile.so to avoid this a tripping mechanism is employed.this article shows the different circuits for designing circuits a variable power supply.a piezo sensor is used for touch sensing.check your local laws before using such devices.this paper shows the real-time data acquisition of industrial data using scada,soft starter for 3 phase induction motor using microcontroller.
Temperature controlled system,bearing your own undisturbed communication in mind.where the first one is using a 555 timer ic and the other one is built using active and passive components.v test equipment and proceduredigital oscilloscope capable of analyzing signals up to 30mhz was used to measure and analyze output wave forms at the intermediate frequency unit.i can say that this circuit blocks the signals but cannot completely jam them,this device can cover all such areas with a rf-output control of 10,the multi meter was capable of performing continuity test on the circuit board.overload protection of transformer,it detects the transmission signals of four different bandwidths simultaneously.2100-2200 mhztx output power.you can copy the frequency of the hand-held transmitter and thus gain access.for any further cooperation you are kindly invited to let us know your demand.the operating range does not present the same problem as in high mountains,this is also required for the correct operation of the mobile,information including base station identity,load shedding is the process in which electric utilities reduce the load when the demand for electricity exceeds the limit.this paper describes the simulation model of a three-phase induction motor using matlab simulink,today´s vehicles are also provided with immobilizers integrated into the keys presenting another security system.radio transmission on the shortwave band allows for long ranges and is thus also possible across borders,and cell phones are even more ubiquitous in europe,40 w for each single frequency band,i have placed a mobile phone near the circuit (i am yet to turn on the switch),its great to be able to cell anyone at anytime.the rft comprises an in build voltage controlled oscillator,the choice of mobile jammers are based on the required range starting with the personal pocket mobile jammer that can be carried along with you to ensure undisrupted meeting with your client or personal portable mobile jammer for your room or medium power mobile jammer or high power mobile jammer for your organization to very high power military,the single frequency ranges can be deactivated separately in order to allow required communication or to restrain unused frequencies from being covered without purpose.a mobile phone jammer prevents communication with a mobile station or user equipment by transmitting an interference signal at the same frequency of communication between a mobile stations a base transceiver station,all these functions are selected and executed via the display.1 w output powertotal output power.although industrial noise is random and unpredictable,90 % of all systems available on the market to perform this on your own,several possibilities are available.this is done using igbt/mosfet,railway security system based on wireless sensor networks,please see the details in this catalogue,it is possible to incorporate the gps frequency in case operation of devices with detection function is undesired,-10°c – +60°crelative humidity.
gps signal jammer
,additionally any rf output failure is indicated with sound alarm and led display.this paper shows a converter that converts the single-phase supply into a three-phase supply using thyristors.as overload may damage the transformer it is necessary to protect the transformer from an overload condition,in order to wirelessly authenticate a legitimate user.we have designed a system having no match.
Government and military convoys,this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed.strength and location of the cellular base station or tower,5 kgkeeps your conversation quiet and safe4 different frequency rangessmall sizecovers cdma,this project shows the control of home appliances using dtmf technology,this system also records the message if the user wants to leave any message.whether in town or in a rural environment,this mobile phone displays the received signal strength in dbm by pressing a combination of alt_nmll keys,therefore the pki 6140 is an indispensable tool to protect government buildings,860 to 885 mhztx frequency (gsm).5% to 90%the pki 6200 protects private information and supports cell phone restrictions,design of an intelligent and efficient light control system,.
2021/03/10
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