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FSK modulated wave file

Hey guys, 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...

PSK instead FSK?

Hi, 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. Thanks ...

xr2211 & non coherent fsk demodulation

Hello, 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...

Is there a software FSK encoder API for PC using no addtl hardware?

Hi All, 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...

software for generating FSK modulated signals

hi 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 modem ? i dont have any backgound of DSP so i would really be thankful for yo...

Is frequency multipliers suitable for boradband FSK?

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 . ...

Who made the comment about modems and FSK signals?

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 per...

Few taps Filters for FSK?

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...

FSK bandwidth

What is the estimated bandwidth using Carson's rule when your separation is 19.8 kHz, the baud rate 19.2 kBaud/s modulation is FSK, NRZ line coding and the crystal tolerance is negligible? Thanks ...

FSK Demodulation (help urgently needed)

Hi 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 V.23 1300 hz is frequency for mark(1) 2100 hz is frequency for spcae(0) 120...

FSK and timing recovery

Hi, 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...

Multicarrier modulation scheme vs FSK

Hey, What is the difference between multicarrier modulation and FSK (Frequency Shift Keying)? Can OFDM considered to be a hybrid of the two? Thanks TD ...

FSK demodulator code?

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? Thanks, Scott ...

Re: FSK Correlation Demodulator

Vale_a_pena wrote: > I can try to help you Opamp. > > Even without money :) > > When you mix two signals: y1*y2 with y1 FSK signal and y2 a > sinusoid > > You obtain a result varying in time (y1*y2)(t) > > > Correlation is the integral during a period of T o...

PC FSK decoding - stuck beginner!

Hi, 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 out. I'm doing my work in Matlab/Simulink for now for simplicity. So far I've tried: - Goertzel algorithm as used for dtmf -...

fsk demodulation

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 throughput involve...

FSK encoding: alternatives to Manchester and NRZ

Hi all, I noticed a lot of FM related questions this month, so here is another one... 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 ...

Coherent FSK

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...

Re: FSK mod and demod

Gunstinger wrote: > 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...

Anyone have a Good filter for FSK with short delay

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...

Re: Detectiong CW

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? > > > John, The CW pitch-shifting feature is in the Timewave DSP-5...

FSK - sample rate and bit depth

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 some questions. 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...

FSK modulation and clean FFT

Hi, 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 ...

Receiving symbols using non-coherent M-FSK

Hi There, 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 environment. ...

ping: Jim Thompson

Jim, 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 used to...

Sub : Help on FSK demodulation

Hello I am using binay FSK. The symbol duration is 'T'. Let the two signal frequencies be f1 and f2. Ideally, we need to select f1 and f2, such that (f1-f2)= k/T; {k=1,2..}. Both my frequencies are less that 2kHz. 'T' is in the order of 20 micro secs. My question: 1.In a practic...

Integer low-pass filter for FSK-modem

Hi, I need to implemement a simple 1200bps FSK-demodulator for 8khz sampling-rate. I want to use the approach to multiply the signal with itself shifted by PI/2. Afterwards I want to low-pass the result to obtain my "bits". I have already done this for V.21 successfully, but now I need to do ...

GMSK demodulation question

A common way of demodulating a 2-FSK signal involves shifting the complex baseband up and down by the deviation, convolving each shifted result with a rectangular filter, and differencing the magnitudes at the filter outputs. This essentially places a sinx/x response at each tone frequency, and w...

FSK Modulation/ demodulation

Hi I have to communicate with telephone which is sending us data that is in voice band and FSK modulated. I dont have an fsk modem so i am trying to do FSK demodulation in software. I'll record that data in a wave file and then analyise it. i dont have any signal processing background and i a...

FSK Modulation/ demodulation

Hi I have to communicate with telephone which is sending us data that is in voice band and FSK modulated. I dont have an fsk modem so i am trying to do FSK demodulation in software. I'll record that data in a wave file and then analyise it. i dont have any signal processing background and i a...

Re: classification of offset 8-psk

On Wed, 24 Jan 2007 12:11:19 -0600, "pankaj_029" wrote: > Hello friends, > > I would like to know if it would be correct if we classify the 3pi/8 > offset 8-psk modulation scheme used for EDGE as a type of linear CPFSK? > I am quoting this statement based on the understanding that GMSK u...

frequency offset compensation for FSK signals

Hello, everybody. My question is about method for compensate frequency offset in recieved FSK signal. I use frequency detector to get baseband signal and then feedback timing error correction based on Mueller and Muller timing error detector. I need some blind or data directed algorithm for carrier...

Re: Simple 150hz Low Pass Fiter using FFT?

Hi Ben, "Ben Jackson" wrote: > > I'd develop this kind of thing in Matlab/Octave/Scilab and then translate > to VC++ once your algorithm was working. > > You'll also need to know the modulation. WWV has a 100Hz subcarrier > with pulse-width modulation containing the BCD time informat...

Re: convert FM signal into bit sequence

VSP wrote: > AIM: To transmit a sequence of bits > BACKGROUND: I have chosen to use FM Transmission. So from the sequence of > bits that i have, I generate an AM wave* (it is similar to a square wave > since there are only two amplitude levels +5v and 0v), which I feed into > an FM Transmi...

Re: Manchester encoded FSK

john wrote: > John Herman wrote: > > Manchester isn't FSK unless you are frequency modulating a carrier with the > > output of the Manchester encoder. If you are using a carrier, you will have a > > lower bit error rate with NRZ than Manchester because of the higher bandwidth > > required...

Is this FSK

Hello! Can signal on pictures from this links http://oss.unist.hr/~jvrlic/dokumenti/DSCsignal1.jpg http://oss.unist.hr/~jvrlic/dokumenti/DSCsignal2.jpg http://oss.unist.hr/~jvrlic/dokumenti/DSCsignal3.jpg be FSK V.23 signal? (1.200 bps, 1300 Hz "1" and 2100 Hz "0") On pictures there i...

FSK tuning/lissajous question

Hi group, I have a question about the phase behaviour of bandpass filters. For my software FSK modem project I'm using a two-stage cascaded set of recursive bandpass filters (set for a bandwidth of 200 Hz.) I found the formula for the calculation of the 5 parameters A0/A1/A2/B1/B2 in "The...

Simple DSP Solution

Hey all: I'm working on a project for a retrocomputing hobby and had a question that needs only minor DSP knowledge to answer. But I'm having a hard time phrasing it so please bear with me. The Atari 8-bit line of computers could be connected to a special tape recorder to save and load programs....

Re: How does PCM-Demodulation work?

On Apr 25, 12:01 am, "Green Xenon [Radium]" wrote: > Hi: > > How does a PCM-demodulator work? > > Thanks, > > Radium Your question is very broad. Once an analog signal has been sampled and put into PCM form (e.g., A/D samples), the resulting PCM bits can then be used to modula...

Re: SNR of a Signal?

another related problem (i'm relatively new to signal theory) i want to decode a SITOR-B signal (FSK) containing two unknown frequencies. in fact, they are known, but we do not know if the rf receiver is tuned precisely, nor if the baseband suffers a time-drift 1) is it a good idea to esti...