Though my problem is do a FSK modulation os an ascii string and send it to
telephone between "init ring" and "full ring" , I don't know how to test.
Is there a software FSK demodulator free somewhere? Can I get some
standard FSK modulated file to test the decoder? So that I am test my c...
I just started up some reading on Digital Communications. I need some
information about PSK vs FSK for use in DSP. Can anyone explain in few
words the advantages of using PSK instead FSK?
Will appreciate any help in this regard.
I am using the XR 2211 to demodulate a non coherent fsk signal. It
works but I would like to know how to evaluate the theoritical BER
performance of this demodulation. But all the non coherent fsk
receivers that are mentionned on the web dont use a pll ... any idea ?
thank you very m...
We need an API module to allow us to send data using the FSK
(Frequency Shift Keying) modulation. This module is to run on a PC and
may use no additional hardware except for the built in sound card.
The module will allow us to convert ASCII characters to their FSK
sound and play tha...
I have to generate signals with data encoded in them using FSK, 1300Hz
for mark and 2100Hz for space with a baud rate of 1200. i dont have an
FSK modulator so is there any software that could do this over voice
i dont have any backgound of DSP so i would really be thankful for yo...
there are many applications use frequency multipliers to improve the
deviation of narrowband FSK . i wonder is it suitable for boradband FSK?
For example,the input signal should be 4FSK,and the frequencys is
67MHz/69MHz/71MHz/73MHz,the symbol rate is 10M .
I think some respondant named 'v' made a remark in response to a post I made
last week regarding FSK decoding and filtering, but the post has been
removed. The remark concerned the special processes that have to be done
detecting FSK tones that are very short in the sense that the number of
Does anyone have any suggestions for an IIR or FIR band pass filter that
will isolate the two tones of an FSK signal which an integrate and dump
scheme can then be applied to?
I need to minimize the delay since this FSK signal comes from scanned radio
frequencies. I need to detect the signal f...
Found this board, and hopefully someone can give me a helping hand.
I'm using labview with a DAQ. It's acquiring a signal and I take a power
fft with peak hold averaging on. In this spectrum, there are atmospheric
noise, some other signals with large BW about 250 hz, and signals that...
I m implementing fax/modem detection. So far it is based on CNG and CED
tones. Goertzel's algorithm is used for tones detections and seems to work
fine. However I would like to increase reliability, specialy for cases when
such tones are not present or missed. Idea is to do it by detecting...
I am trying to Extract Caller ID from FSK v.23 Encoded CLI Packet which
has been stored in audio format in pc. To demdulate FSK i am using two
Bandpass Filters centered at Mark and Space Frequency. According to FSK
1300 hz is frequency for mark(1)
2100 hz is frequency for spcae(0)
I'm trying to gain an understanding of how to do timing recovery or symbol
synchronization in a digital radio receiver but I need something clarified.
The methods I have found information on (Mueller & Mueller, Early-late,
Gardner etc) seem to be intended for linear modulation schemes but wha...
With the right filtering, an FSK signal can be viewed as two
complementary OOK (on-off keyed) signals. Is the optimal FSK
demodulator more optimal, less optimal, or equivalent to two optimal
OOK demodulators with their outputs combined?
Randy Yates % "Watching all the d...
I'm looking for code, either in ANSI C or assembly for the ARM7TDMI, that'll
demodulate 1200 baud FSK, in particular 1200 baud Bell 202 keying like that
found in caller ID systems. Any suggestions?
I'm looking at demodulating a GMDSS/DSC (Digital Selective-Calling)
100 baud FSK (1700 Hz center, +/- 85 Hz) signal (per ITU-R M.493-12).
The spec says nothing about whether it's continuous-phase FSK or not.
I've found on the net that DSC is similar to SITOR-B, and further that
I am trying to understand fsk demodulation in general. Is there an
industry standard set of specific demod schemes or just classes of
particular methods (i.e. matched filter, correlation, coherent vs
non-coherent) that are invoked on a project by project basis?
I have a pretty elementary question.
For an unshaped, 2-FSK signal, the modulation index h is defined
as the ratio of the difference between the two tone frequencies
to the symbol rate.
For shaped 2-FSK, how is h usually defined? I can think
of a few possibilities:
(1) Base it on the pe...
> I can try to help you Opamp.
> Even without money :)
> When you mix two signals: y1*y2 with y1 FSK signal and y2 a
> You obtain a result varying in time (y1*y2)(t)
> Correlation is the integral during a period of T o...
I'm urgently trying to get my head around methods for decoding an FSK
encoded signal on my PC.
I have a .wav file of the transmitted data, and I want to get the data
I'm doing my work in Matlab/Simulink for now for simplicity.
So far I've tried:
- Goertzel algorithm as used for dtmf
BT denotes the product of the 3 dB bandwidth of the shaping
pulse in an FSK system and the symbol time.
My question has to do with the conventional definition of B.
My first thought was to use the 3 dB bandwidth of a bandpass
function obtained by translating the baseband pulse up
to the FSK...
I am a novice in DSP.I am trying to demodulate a FSK signal wherein the
mark and space frequencies are 16MHz and 24MHz respectively.I am thinking
of using delay and multiply method.Can this be implemented using an
ADSP-2181?More specifically will the DSP be able to handle the high
I manage a hardware engineering group for a telcom company and I am
beginning to look around for FPGA IP to implement both FSK modulation
and demodulation. I am wondering if any of you have any experience
with any of the IP around today. The demodulator is the most difficult
I noticed a lot of FM related questions this month, so here is another
I am transmitting FSK using a MICRF505 transceiver chip. The FSK
modulator in this chip requires a bit encoding scheme to reduce the DC
content of the bit stream to a manageable level. I am struggling with
A colleague and I are trying to understand the performance limits that
apply to coherent detection of continuous phase FSK in AWGN. As I
understand it, the familiar textbook formula for coherent FSK BER is
derived for the case of square one-bit pulses and tones that are
orthogonal over one bit t...
> Hello I'm stuck with a little problem here in MatLab. What I need to do is
> input a string of text, convert it to binary, and then use FSK to mod it
> together, then demod and and filter it out and convert it back to text
> again. The first part is easy, the input of tex...
I am trying to understand what is meant by continuous phase FSK.
Right now I am of the opinion that it means that a very quick change
in frequency can take place as long as there is no discontinuity in
the time waveform when the frequency change takes place. Is this a
What is the maximum amount of bits-per-symbol of FSK possible using a
telephone system [including the phone lines and any devices from start to
finish of the phone's signal chain]?
Adapting Goertzel algorithm for FSK in a system with a preset sampling
rate, tones and baud rate does not always result in ideal parameters.
Let me try to explain what I mean:
For example, consider a case with Fs=9600, tones 1650 and 1850 Hz, and baud
300. That's N=32 samples per symbo...
I need to find a bandpass filter with as few taps as possible to apply to an
HF radio FSK signal. The reason is that the radio is scanned and the more
taps, the longer it takes before the signal can be recognized which slows
down the possible scan rate.
Can anyone give me any references or id...
In article , "John E. Hadstate" wrote:
> What's the slickest way of turning an I/Q data stream, tuned
> to baseband, into audible Morse Code with user-selectable
> pitch using strictly digital signal processing?
The CW pitch-shifting feature is in the Timewave DSP-5...
I'm working on a couple of demodulators - one for 1200 baud AFSK (and
possibly other bitrates) and one for 9600 baud baseband FSK - and I've got
I'm using an ARM7TDMI chip, so I'm rather CPU constrained. An issue I'm
having trouble with is that the CODEC I'm considering off...
A Bell 202T modem uses FSK modulation (1200HZ, 2200HZ) and send data at
up to 1800 bits per second.
I need to replace an "analog" version of this with a digital version,
sampling the phone line with an A/D and "decoding" the 1's and 0's in
firmware (ARM C).
My question is how.. The modu...
I am involved in the development of an underwater modem. Right now I am
dealing with the simulation stage with simulink.
The modulation scheme I am using is a non-coherent FSK. The carrier
frequencies are 20kHz and 22kHz.
At the demodulator part, I have designed a matched filters...
I'm looking at FSK modulation in matlab, using my own modulator as I
don't have the matlab comms toolbox. In the time domain, the signal
looks fine, but in the frequency domain, it just doesn't seem to work,
I get lots of other garbage in the spectrum. I'm hoping someone can
see an error ...
How does the demodulator of a non-coherent M-FSK system correctly time
the "reading" of the symbols? In the book on Digital Comms by
Proakis, it is mentioned that a bank of 2M correlators can be used.
In the book there is also a model for non-coherent M-FSK in an AWGN
I was perusing your website and happened upon your patent regarding
demodulating of FSK. Is this the currently easiest/best way to decode FSK?
Or would I be better off doing with SW and microcontroller?
I was thinking that a comparator with hysteresis to minimize noise could be
We are looking for a robust FSK demodulator and framer solution for an SDR
application (decoding of simultaneous narrow channels at some kbps each from
a wider baseband stream) : channel filtering, center frequency tracking,
demodulation, bit-level timing recovery, synchronisation...