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server
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K
Ken Taylor
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"sommes" <lkj@jk.com> wrote in message
news:42a552ca$0$621$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
to the received signal, the L1 'pops out'.
What text are you using? There should be an explanation of how information
theory is used on the coded signal to 'amplify' the signal while leaving the
noise at essentially zero.
Ken
news:42a552ca$0$621$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
receiver applies the correct code (each GPS satellite has a different code)
to the received signal, the L1 'pops out'.
What text are you using? There should be an explanation of how information
theory is used on the coded signal to 'amplify' the signal while leaving the
noise at essentially zero.
Ken
S
sommes
Guest
i read from this site
http://www.ictp.trieste.it/~radionet/ghana1998/GPS/DECODING.HTM
Could you please explain that "infomation theory"?
how does receieved signal compare to background noise to achieve a
amplification?
http://www.ictp.trieste.it/~radionet/ghana1998/GPS/DECODING.HTM
Could you please explain that "infomation theory"?
how does receieved signal compare to background noise to achieve a
amplification?
K
Ken Taylor
Guest
"sommes" <lkj@jk.com> wrote in message
news:42a567f1$0$562$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
The 'amplification' is 'virtual' - you are really taking enough samples over
a period of time so as to reduce the errors. Assume you look at a signal
containing noise. Because the noise in it is random, and the PRC code is by
definition also 'random', if you sample and compare the signal with the PRC
over time, they should match just as often as they don't match.
But now if you add the signal from a GPS satellite (which looks like noise
because it uses a PRC for coding), and if the PRC we sample with matches the
satellite's, then there will be times when the sample of the PRC from the
satellite adds to the noise correctly so that we start to get more matches
with the PRC we are sampling with. There only has to be a small number of
times in a sample period when we get the benefit of added matches, but we
can then sample over longer time periods to get lots more matches. In this
way we can resolve the GPS signal from the noise. In the text they make a
fairly spurious, in my opinion, comparism back to a figure of amplification.
What you are really improving is your bit-error rate. It equates to the same
thing, but I don't think they say that part particularly well. My opinion
only.
Is that any clearer than what you read on that site? It's basically the same
words, I can't think of any other way to put it off-hand.
Are you studying for a course or just curious?
Cheers.
Ken
news:42a567f1$0$562$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
text!
The 'amplification' is 'virtual' - you are really taking enough samples over
a period of time so as to reduce the errors. Assume you look at a signal
containing noise. Because the noise in it is random, and the PRC code is by
definition also 'random', if you sample and compare the signal with the PRC
over time, they should match just as often as they don't match.
But now if you add the signal from a GPS satellite (which looks like noise
because it uses a PRC for coding), and if the PRC we sample with matches the
satellite's, then there will be times when the sample of the PRC from the
satellite adds to the noise correctly so that we start to get more matches
with the PRC we are sampling with. There only has to be a small number of
times in a sample period when we get the benefit of added matches, but we
can then sample over longer time periods to get lots more matches. In this
way we can resolve the GPS signal from the noise. In the text they make a
fairly spurious, in my opinion, comparism back to a figure of amplification.
What you are really improving is your bit-error rate. It equates to the same
thing, but I don't think they say that part particularly well. My opinion
only.
Is that any clearer than what you read on that site? It's basically the same
words, I can't think of any other way to put it off-hand.
Are you studying for a course or just curious?
Cheers.
Ken
G
gcd
Guest
Hi,
I suggest a book on spread spectrum may be of use. Try "Spread spectrum
systems.." by Dixon.
The gain you are referring to is called Process Gain. When the received
signal is run through a matched filter or autocorrelator, the energy of the
original signal is reconstructed. The gain acheived is dependant on the chip
rate and bandwidth used.
This concept is also used widely in radar systems. Using a low power spread
or chirped pulse can be run through a matched filter to produce a high power
narrow pulse, providing better jammer to noise ratio, lower probability of
intercept and better range resolution.
If you look for LPI radar or Spread Spectrum, you should find answers.
In essence, the energy of a carrier signal is spread over a wide band width
using the PN code, this will effectivly reduce the energy in any given
bandwidth (W/Hz) and so for a receiver that has no matched filter, the
signal may at or below the thermal or terrestrial noise floor of that
receiver. When the signal is passed through a matched filter the energy of
the spread signal becomes coherent and reconstructs the original signal.
Cheers
Greg
"sommes" <lkj@jk.com> wrote in message
news:42a552ca$0$621$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
I suggest a book on spread spectrum may be of use. Try "Spread spectrum
systems.." by Dixon.
The gain you are referring to is called Process Gain. When the received
signal is run through a matched filter or autocorrelator, the energy of the
original signal is reconstructed. The gain acheived is dependant on the chip
rate and bandwidth used.
This concept is also used widely in radar systems. Using a low power spread
or chirped pulse can be run through a matched filter to produce a high power
narrow pulse, providing better jammer to noise ratio, lower probability of
intercept and better range resolution.
If you look for LPI radar or Spread Spectrum, you should find answers.
In essence, the energy of a carrier signal is spread over a wide band width
using the PN code, this will effectivly reduce the energy in any given
bandwidth (W/Hz) and so for a receiver that has no matched filter, the
signal may at or below the thermal or terrestrial noise floor of that
receiver. When the signal is passed through a matched filter the energy of
the spread signal becomes coherent and reconstructs the original signal.
Cheers
Greg
"sommes" <lkj@jk.com> wrote in message
news:42a552ca$0$621$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
J
Jim
Guest
"Ken Taylor" <ken@home.nz> wrote in message
news:0yepe.5758$U4.811443@news.xtra.co.nz...
made perfect sense to me. Thank you.
Cheers
Jim
news:0yepe.5758$U4.811443@news.xtra.co.nz...
Ken I know next to nothing about the topic except in a general way, and it
made perfect sense to me. Thank you.
Cheers
Jim
S
sommes
Guest
thank all guys...
According from the web
http://www.ictp.trieste.it/~radionet/ghana1998/GPS/DECODING.HTM
What I am thinking is, the PRC is sending in a period(100s), and compare
itself and take the averaging to get a better quality. is it correct?
But the thing is, how can the PRC and background noise ampilify the signal
to make the receiver size smaller?
Thank you for all helps..
I am doing a uni assignment about PRC in spread spectrum system.
According from the web
http://www.ictp.trieste.it/~radionet/ghana1998/GPS/DECODING.HTM
What I am thinking is, the PRC is sending in a period(100s), and compare
itself and take the averaging to get a better quality. is it correct?
But the thing is, how can the PRC and background noise ampilify the signal
to make the receiver size smaller?
Thank you for all helps..
I am doing a uni assignment about PRC in spread spectrum system.
S
sommes
Guest
Amm...
When the recieved signal matched the satellite signal, the recieved
signal(PRC) compare to background noise, when recieved signal compare to
background noise, energy of the
recieved signal is reconstructed, therefore the amplitcation is achieved.
Please correct any mistake. Thank you.
When the recieved signal matched the satellite signal, the recieved
signal(PRC) compare to background noise, when recieved signal compare to
background noise, energy of the
recieved signal is reconstructed, therefore the amplitcation is achieved.
Please correct any mistake. Thank you.
R
Roger Lascelles
Guest
"gcd" <gcdmelbnoSPAM@iimetro.com.au> wrote in message
news:d8455t$j2q$1@austarmetro.com.au...
tell me if this is on the right track :
The receiver pattern runs at a slightly different speed to the satellite
pattern so the two can "strobe" or correlate against each other. Every time
they slide to the correct position, a pulse is produced. The pattern of
those produced pulses is decoded to produce the GPS information.
Roger Lascelles
news:d8455t$j2q$1@austarmetro.com.au...
The website explanation is terribly thin and I need clarification. Can you
tell me if this is on the right track :
The receiver pattern runs at a slightly different speed to the satellite
pattern so the two can "strobe" or correlate against each other. Every time
they slide to the correct position, a pulse is produced. The pattern of
those produced pulses is decoded to produce the GPS information.
Roger Lascelles
C
Clockmeister
Guest
"Rod Speed" <rod_speed@yahoo.com> wrote in message
news:3gjojrFauqhjU1@individual.net...
news:3gjojrFauqhjU1@individual.net...
Poor old Rod is wrong again.
B
Bob Parker
Guest
Geez, they sure don't make it easy, do they? Zilog's desperately
trying to claw back market share, and this kind of needless problem is
going to lose them lots of potential customers.
Good luck with sorting through the mess. It'll be interesting to
get your thoughts about the Encore once you can actually use the
thing.
Regards
Bob
Mark Harriss <billy@blartco.co.uk> wrote:
trying to claw back market share, and this kind of needless problem is
going to lose them lots of potential customers.
Good luck with sorting through the mess. It'll be interesting to
get your thoughts about the Encore once you can actually use the
thing.
Regards
Bob
Mark Harriss <billy@blartco.co.uk> wrote:
K
Ken Taylor
Guest
"sommes" <lkj@jk.com> wrote in message
news:42a58800$0$594$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
systems. This will probably help you more at this stage than more words
saying the right thing.
Good luck.
Ken
news:42a58800$0$594$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
Communications (1982) which have a detailed account of spread-spectrum
systems. This will probably help you more at this stage than more words
saying the right thing.
Good luck.
Ken
R
Rod Speed
Guest
Some gutless fuckwit car crasher desperately cowering behind
Clockmeister <no-one@nowhere.com> desperately attempted
to bullshit its way out of its predicament in message
news:42a39af8@duster.adelaide.on.net...
and fooled absolutely no one at all, as always.
No surprise that it only ever gets to crash cars.
Clockmeister <no-one@nowhere.com> desperately attempted
to bullshit its way out of its predicament in message
news:42a39af8@duster.adelaide.on.net...
and fooled absolutely no one at all, as always.
No surprise that it only ever gets to crash cars.
M
Max Harding vk3jin
Guest
you will get this from www.hcsd.com.au
you can either hire or purchase.02-6452-5322 they are in Cooma .
"Baz" <bastermelcal@hotmail.com> wrote in message
news:42a272bf$0$33354$c30e37c6@lon-reader.news.telstra.net...
you can either hire or purchase.02-6452-5322 they are in Cooma .
"Baz" <bastermelcal@hotmail.com> wrote in message
news:42a272bf$0$33354$c30e37c6@lon-reader.news.telstra.net...
Guest
Zilog technical support sux.
I'm still waiting for a response from them weeks after asking my
question despite the automated email promising a response in 3-5
working days.
Use the yahoo groups to get community support is much better.
My XP kit is due to arrive next week so I can't help out till then.
Regards,
Dean.
I'm still waiting for a response from them weeks after asking my
question despite the automated email promising a response in 3-5
working days.
Use the yahoo groups to get community support is much better.
My XP kit is due to arrive next week so I can't help out till then.
Regards,
Dean.
B
bodgy
Guest
I bought this kit, I found on my laptop that the USB
programmer/debugger wouldn't work (although recognised) on my PCMIA 4
port USB2.0 hub.
Bung it into a normal 1.1 hub on the motherboard and it all worked.
The jumpers (on mine) were in the correct position for the led demo,
and the uP was preprogrammed with it.
What they don't say is that to use the debugger/programmer the debug
jumper must be in position.
Colin
programmer/debugger wouldn't work (although recognised) on my PCMIA 4
port USB2.0 hub.
Bung it into a normal 1.1 hub on the motherboard and it all worked.
The jumpers (on mine) were in the correct position for the led demo,
and the uP was preprogrammed with it.
What they don't say is that to use the debugger/programmer the debug
jumper must be in position.
Colin
D
David L. Jones
Guest
Mark Harriss wrote:
You can easily lock up their ISP port making the chip useless in any
serial programmer. Just what you need when you have a part soldered
onto the board - real nasty.
Their ATtiny26 device wasn't compatible with their own development
system either - needed modifications, and wasn't adequately documented.
I certainly had a very unpleasant introduction to Atmels.
Dave
Atmels certainly ain't the ducks guts either.
You can easily lock up their ISP port making the chip useless in any
serial programmer. Just what you need when you have a part soldered
onto the board - real nasty.
Their ATtiny26 device wasn't compatible with their own development
system either - needed modifications, and wasn't adequately documented.
I certainly had a very unpleasant introduction to Atmels.
Dave
J
JustCurEus
Guest
On Sat, 4 Jun 2005 7:57:54 -0400, JustCurEus wrote
(in message <0001HW.BEC70F820001C67D151EC050@newsgroups.comcast.net>:
their response. I was only looking for the MIDI THEREMIN article copies for
information, as I believe that it most likely cannot be constructed by the
article 'cuz in most likelyhood it uses a PICmicro and I am sure that they do
not provide code in the magazine... at least EPEonline does not show it in
their magazine-although they do allow FTP download of source code.
again, thanks (USA)
-------------------------------------------
Subject: Silicon Chip Online: Online Subscriptions [Web Publications Our
Ref#47643] From: "Joanna Hoare" <publishing@webpublications.com.au>
To: StevenThompson1960@yahoo.com Date: Fri, 20 May 2005 09:49:36 +1000 (EST)
Dear Steven
Unfortunately the site can not be viewed in PDF format. It can only be
viewed online.
The Silicon Chip Subscription options are on a yearly basis. You can purchase
the years worth of issues that include the articles you are after for $52.23
See link below for subscription options in US currency.
http://www.siliconchip.com.au/cms/access/subprices.html?currency=USD
Kind Regards
Joanna
Web Publications
(in message <0001HW.BEC70F820001C67D151EC050@newsgroups.comcast.net>
:Thanks for looking at my posting. Below is my email to Silicon Chip and
their response. I was only looking for the MIDI THEREMIN article copies for
information, as I believe that it most likely cannot be constructed by the
article 'cuz in most likelyhood it uses a PICmicro and I am sure that they do
not provide code in the magazine... at least EPEonline does not show it in
their magazine-although they do allow FTP download of source code.
again, thanks (USA)
-------------------------------------------
Subject: Silicon Chip Online: Online Subscriptions [Web Publications Our
Ref#47643] From: "Joanna Hoare" <publishing@webpublications.com.au>
To: StevenThompson1960@yahoo.com Date: Fri, 20 May 2005 09:49:36 +1000 (EST)
Dear Steven
Unfortunately the site can not be viewed in PDF format. It can only be
viewed online.
The Silicon Chip Subscription options are on a yearly basis. You can purchase
the years worth of issues that include the articles you are after for $52.23
See link below for subscription options in US currency.
http://www.siliconchip.com.au/cms/access/subprices.html?currency=USD
Kind Regards
Joanna
Web Publications
M
Mark Harriss
Guest
Bob Parker wrote:
I had a response from Vinay (Bombay???) at Zilog telling me a set of
jumper settings and sequence of settings for the software which is
pretty much what I had after reading all the docs: there does seem to
be some kind of problem here: I tried a second board and smart cable
with exactly the same result: the software spots the cable ok but it
gives a comms error when I try to program it. I'll try a second computer
and see what happens.
Regards
Mark
I had a response from Vinay (Bombay???) at Zilog telling me a set of
jumper settings and sequence of settings for the software which is
pretty much what I had after reading all the docs: there does seem to
be some kind of problem here: I tried a second board and smart cable
with exactly the same result: the software spots the cable ok but it
gives a comms error when I try to program it. I'll try a second computer
and see what happens.
Regards
Mark
B
Bob Parker
Guest
Why is it that documentation seems to be the weak point with most
brands of micros? The only doco I thought was excellent was for the
old Motorola ones.
I hope you can get the Encore working somehow. The actual device
looks really nice, from what little I've read about it.
Good luck!!
Regards,
Bob
Mark Harriss <billy@blartco.co.uk> wrote:
brands of micros? The only doco I thought was excellent was for the
old Motorola ones.
I hope you can get the Encore working somehow. The actual device
looks really nice, from what little I've read about it.
Good luck!!
Regards,
Bob
Mark Harriss <billy@blartco.co.uk> wrote: