Hi Guys, I'm trying to help someone understand the operation of a discrete single-sideband (SSB) demodulation system that is being...

Hi Guys, I'm trying to help someone understand the operation of a discrete single-sideband (SSB) demodulation system that is being proposed to replace an older analog SSB demodulation system. Having not thought about SSB systems for many years, I've been trying to figure out how the "phasing method" of SSB demodulation works. In trying to model this "phasing method" using Matla...

Hi all, I'm implementing demodulation schemes in digital form and I'm currently trying to establish what the advantages and disadvantages are...

Hi all, I'm implementing demodulation schemes in digital form and I'm currently trying to establish what the advantages and disadvantages are of each domain. I've written down what I think are the most important, and would be interested in hearing if I've covered all the bases and if the information is accurate. Thanks. ***Pros*** * Flexibility – different demodulation scheme

Hi, All i have some simple questions for HAM Radio/Caller ID FSK demodulation. Studying FSK demodulation using matched filter it is known that...

Hi, All i have some simple questions for HAM Radio/Caller ID FSK demodulation. Studying FSK demodulation using matched filter it is known that the output will be +ve or -ve for mark and space frequency, i am unable to figure out that 1. What will be the output of matched filters when neither 1 (1200 Hz) or 0 (2200 Hz) is transmitted. ? How to know this condition. 2. Will matched filter(non ...

Hi, All i have some simple questions for HAM Radio/Caller ID FSK demodulation. Studying FSK demodulation using matched filter it is known that...

Hi, All i have some simple questions for HAM Radio/Caller ID FSK demodulation. Studying FSK demodulation using matched filter it is known that the output will be +ve or -ve for mark and space frequency, i am unable to figure out that 1. What will be the output of matched filters when neither 1 (1200 Hz) or 0 (2200 Hz) is transmitted. ? How to know this condition. 2. Will matched filter(non ...

Hi guys, Some weeks ago I posted a message asking for help in understanding the 'phasing method' of single sideband (SSB)...

Hi guys, Some weeks ago I posted a message asking for help in understanding the 'phasing method' of single sideband (SSB) demodulation. You guys helped me out, and I learned so much that I wrote a blog on that SSB demodulation method. In case anyone's interested, the blog is at: http://www.dsprelated.com/showarticle/176.php See Ya', [-Rick-]

I am trying to build a binary CPFSK demodulator with self synchronization. Modulation index is not fixed. I kind of prefer coherent demodulation,...

I am trying to build a binary CPFSK demodulator with self synchronization. Modulation index is not fixed. I kind of prefer coherent demodulation, but not sure how to do the synchronization. The following is some understandings I have during the literature survey, I appreciate if I can get some comment on my understandings. 1. One type of coherent demodulation I know of is ZCD based and using...

I am trying to build a binary CPFSK demodulator with self synchronization. Modulation index is not fixed. I kind of prefer coherent demodulation,...

I am trying to build a binary CPFSK demodulator with self synchronization. Modulation index is not fixed. I kind of prefer coherent demodulation, but not sure how to do the synchronization. The following is some understandings I have during the literature survey, I appreciate if I can get some comment on my understandings. 1. One type of coherent demodulation I know of is ZCD based and using...

I am doing digital FM demodulation using the common ATAN2 and first difference method. When the carrier is offset from center, there is...

I am doing digital FM demodulation using the common ATAN2 and first difference method. When the carrier is offset from center, there is a non-linear region that appears and seems to be tied to the FM demodulation sample rate. Without be able to change the FM demodulation sample rate, are there any work arounds from this non-linear region? This non-linear region is just outside my bandwidth of ...

Hi all!! I have implemented BPSK modulation with DSK 6713.I'm writting a program to implement BPSK modulation and demodulation on the same Kit...

Hi all!! I have implemented BPSK modulation with DSK 6713.I'm writting a program to implement BPSK modulation and demodulation on the same Kit DSK 6713, but it doesn't run. Can we implement BPSK modulation and demodulatio on the same Kit DSP?. I wil post my source code later! By the way! I also have a project about QPSK demodulation, but when I recover carrier wave, I only recover sin wave(in_pha...

We know coherent and noncoherent FSK demodulation can be done by using correlator and energy detector. In Fading channel case with noncoherent...

We know coherent and noncoherent FSK demodulation can be done by using correlator and energy detector. In Fading channel case with noncoherent demodulation, we can use the energy detector. But in coherent case, how could we use the channel state information to detect signal..... BFSK: h is the channel fading...x is the transmitted signal...n# is noise in channel# rx1 = hx + n1 rx2 = n2...

hey guys, just wanted to know if any1 could please shred sum light on wat would the differnce in demodulation schemes of double side band...

hey guys, just wanted to know if any1 could please shred sum light on wat would the differnce in demodulation schemes of double side band suppressed carrier and single side band suppressed carrier. This is what i done with matlab coding for modulation and demodulation. 1. DSB-SC: - Modulation: (message signal 500hz) multiply by (carrier frequency 7000hz) ie: cos (2 pi 500 t) x cos (2pi700...

Hello, PLL is a good way to do FM demodulation in analogue domain. What about its use in digital domain? Why not to use a digital PLL to do...

Hello, PLL is a good way to do FM demodulation in analogue domain. What about its use in digital domain? Why not to use a digital PLL to do FM demodulation? what is advantages(if any) and disadvantages of this technique? Regards

Hello, I am doing IQ demodulation in DSP. Only one reference signal(sin) fo is coming as reference. I have generate 2fo,4fo from it and...

Hello, I am doing IQ demodulation in DSP. Only one reference signal(sin) fo is coming as reference. I have generate 2fo,4fo from it and also generate orthogonal signal of each of it for IQ demodulation. All these frequency should be phase looked with the reference signal.My question is how to generate these.Any special techniques for generation. Any reference or suggestion will be great. ...

Hello, I am finding the amplitude of the signal using complex demodulation (quadrature demodulation). I wanted to know maximum accuracy to...

Hello, I am finding the amplitude of the signal using complex demodulation (quadrature demodulation). I wanted to know maximum accuracy to which the amplitude of the one of the frequency contained in phase modulated signal(which is the input) can be estimated.The accuracy to which the amplitude obtained should be 10^-8 (between actual and estimated by this method). So i wanted to know if t...

Dear All, Okay, probably this sound a bit silly, but what happens when repetition coding is used and when soft demodulation is used ? Soft...

Dear All, Okay, probably this sound a bit silly, but what happens when repetition coding is used and when soft demodulation is used ? Soft QAM demodulation produces Log Likelihood Ratio (LLR), and should I take average value of the repeated symbols ? Here's the simple view of the receiver Channel --> Soft QAM demodulator--> Repetition Decoding--> De Interleaver--> FEC decoder Any impac

I'm working on FSK demodulator with the TMS320C6711 DSK. I've done this demodulation with the method where the signal and its delayed version...

I'm working on FSK demodulator with the TMS320C6711 DSK. I've done this demodulation with the method where the signal and its delayed version are multiplied together and then low-pass filtered. But this demodulation technic is only working if the sample rate is an integer multiple of the baud rate. Does someone know a technic or an algorithm which allow a demodulation of a 300 baud rate signal wit...

i came to know that FM demodulation can be done through envelope detection. i have implemented the FM demodulation using envelope detection and i...

i came to know that FM demodulation can be done through envelope detection. i have implemented the FM demodulation using envelope detection and i was unable to detect the original signal. i have not implemented the limiter circuit for this. i have passed the FM signal directly to the BPF followed by differentiator and envelope detector how to implement the limiter circuit. please help me. ...

Hi there! I'm finding hard to get information about "switched gain AM demodulation" and how to implement it. Apparently this demodulation ...

Hi there! I'm finding hard to get information about "switched gain AM demodulation" and how to implement it. Apparently this demodulation techique involves synchronization with the signal carrier.. Can anybody provide some hints? Regards, Luke

Dear all, I saw in google that costas loop can be used as the carrier recovery mechanism for coherent GMSK signal demodulation, but I did not...

Dear all, I saw in google that costas loop can be used as the carrier recovery mechanism for coherent GMSK signal demodulation, but I did not find any detailed article about it. Can anybody give a good reference to implement costas loop for gmsk? Any useful weblink or technical article will be appreciated. Richard

Hi all, I am new to much of this, so thanks in advance for your patience. Where can you find C++ (or C or C#) source code for ASK, FSK, PSK,...

Hi all, I am new to much of this, so thanks in advance for your patience. Where can you find C++ (or C or C#) source code for ASK, FSK, PSK, QAM, PPM, and BPSK demodulation schemes? I have a feeling that if they exist they won't be free, but that's a problem for another day...Matlab and LabView have great modulation/demodulation toolkits, but we are looking for source code. Thanks again--Ni...