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i was wondering if anyone know how much AM demodulation gets better (SNR and linearity) when using product demodulator than using envelope detector.
To demodulate an AM signal you can use the formula sqrt(I^2 + Q^2) where I,Q are In phase and quadrature components. Then extract the dc component of the signal (= LP filter) which is related to the carrier amplitude. For suppressed carrier you could extract the dc component directly from the envelope of the modulated signal. Regards Mow
AM demodulation : an envelope detector : diode into RC circuit FM demodulation : cut off slope of bandpass filter converts change in frequency to AM signal and then an envelope detector : diode into RC circuit
To demodulate AM, I use the formula am = sqrt(I*I + Q*Q) I am mixing an AM IF signal to baseband, i.e. carrier plus 2 sidebands. My test signal is modulated at 800Hz. When I look at the demodulation, it looks OK when I mix perfectly to 0Hz, but as the transmitted signal moves up or down frequency, I end up with 2 frequencies in the demodul
?In AM synchronous demodulation, Why we don?t divide the received signal, m(t)coswt, by cos(wt) using a simple divider circuit instead of multiplying by cos(wt)?? I asked this question to two professors and I got different answers: #Professor 1 Reply: "For your scheme to work you must know exactly what the frequency w is that the transmitter
in practical systems the if = 10.7 MHZ or 455K 10.7MHz for FM and 455K for NBFM or AM , it can be also 70KHz
Hello to everyone! I am new to this forum and i don't have huge knowledge in electronics. Just the please excuse anything that may seem akward to you ( i mean of what i write :blush: ) The question i have is : Suppose we have two signals. Call them m1(t) and m2(t). We modulate each one with AM modulation. So we get two separate
I have a ciruit diagram of an AM RECEIVER (118Mhz-136Mhz) in which the IC CA3075(FM IF AMPLIFIER LIMITER) and CA3012(FM IF WIDEBAND AMPLIFIER) are being used. I dont get it why are FM ICs being used in an AM receiver.Please help.
Hi, Thanks for reading my message. I want to make an AM demodulator that demodulates up to 4 fixed frequencies. The AM demodulation frequencies are 83kHz, 200kHz, 455kHz and 800kHz. Please take a look at my schematic. The AM signal is passed through C1. Please tell me what input capacitor is better (10NF or 100NF? 100NF has more inductance? or i
Hi I have a question about direct down-conversion mixer Right now i have a RF AM signal like this. attachment1 ook It has it's carrier freq & signal freq we know that we can generate the above waveform by using a single mixer attachment2 mixer My question is ,can we demodulate this AM signal by a using a Direct down-conversion mixer
Hi I am interested in lowfrequency RF-simulation, and I wonder if there is a software that lets me simulate circuits with various types of tapped inductor and tapped transformers. Especially I want to simulate an AM-demodulation stage with an inductor cupled to the transistor collector, an inductor at the emitter an iron core that couples th
I came across the following site ( ) using TV tuner as communication receivers. The tuner mentioned is difficult to source now. With the availability of cheap TV cards for the PCs (with built in tv tuner outputting video and audio directly), can the following be done (the tuner will be remov
I have done something on softradio: Down Convertor, CW, SSB, AM demodulation, noise design is based on Blackfin BF531 and is still under going, discussion are welcomed. mike -----------------------------------------------------------
Anywhere but radshack. I need to find a better parts dealer. However I am going to try a silicon maybe even learn how to build RF preamps.
Can superheterodyne receivers demodulate FM and PM signals ? or is it only applicable for AM demodulation ?
Hi, My code is as follows: Fs=100e2; T=1/Fs; L=10000; t='/Fs; fm=10; fc=48e1; ka=0.1; %% 0demodulation =butter(5,fc*2/Fs); z=filter(b,a,y); NFFT=2^nextpow2(L); f=Fs/2*lin
Can anybody name an IC that can be used for AM demodulation!!! I want to remove the carrier from Amplitude modulated signal of frequency 455 KHz and receive the signal in it. But no circuit. IC is required!! plz urgently To detect the modulation signal from the AM spectrum, you need literally a "crystal s
How to program a VHDL to implement demodulation of AM, FM, PM, PSK, QPSK, PCM, FSK, ASK, CDMA.. on FPGA (Xilinx) could anybody give me some advice, CORDIC or some other algorithms are appreciate, thx in advance.
Hi! Please help me with these questions: 1/With an AM DSB modulation system using Balanced Modulator,what is suppressed-carrier figure?And how to measure it? 2/With SSB demodulation system using Product Detector,if LO frequency increases,how is the output frequency at USB and at LSB? Thanks!
Oh... I read a topic here about soft radios dated 2 years ago... i cant believe its still proprietary. perhaps there are public algorithms ^_^ Added after 4 hours 58 minutes: I have done some research (inside and outside of the forum), some have implemented FM demodulation using all digital PLLs and FIR fil
hello I need a a carrier recovery system for demodulation of am and dsb that generate a synchronous signal with carrier frequency to mpultiply with am and dsb signals Thanks lot
why we are going for am and fm modulation and demodulation?
Hi, I am using E4404B. The difference is the frequency range. It is quite useful as it is a simple way of qualify your circuitry performance. In this case, it is vector analysis such as EVM, phase error, frequency error, IQ imbalance.... What is the guidance you are looking for?
Hello I am searching for a SSB (single sideband ) demodulation routine or core or whatever in VHDL!!! pls answers ich u know something
Hello I am searching for a SSB (single sideband ) demodulation routine or core or whatever in VHDL!!! pls answers if u know something
Please help me on this project. SPECIFICATION: 1)I want to control a AM reciever circuit with computer so that I recieve local radio transmission and listen the recieving signals on computer's sound card. 2)I want to tune channels by computer.
The Costas loop is an optimum solution. All methods will have the 180 degree phase ambiguity. There are two ways around this. One is to have a known preamble. The other is the differential way which will produce twice the BER because one received bit error will affect two data bits.
Personally I wouldn't use CD4046 as FM-demodulator. So far I haven't come across even one properly working demodulator based on this IC. Different story with ICs such as NE564: always works veery well and you can find plenty of applications and diagrams on the web. Anyhow, if you would like to continue with 4046 could you pkease advice your con
I have the same problem, have you found the answer? do you know how to perform soft decoding for LDPC codes by using I and Q data form demodulator? Please inform me if you have any paper about this topic Thanks in advance
Hi all Perhaps my question is stupid, but I am momentary at the end of my ideas. What the heck is the demodulation of AM if I have a I/Q signal ? My homebrew HDR-2005 (= HardwareDefinedRadio 2005 ;-) is a mixture between QRP2001, SDR-1000 and other concepts. It sounds great in SSB. I demodulate LSB, USB or both but not AM. Yes, yes I know M = s
Hi all Perhaps my question is stupid, but I am momentary at the end of my ideas. What the heck is the demodulation of AM if I have a I/Q signal ? My homebrew HDR-2005 (= HardwareDefinedRadio 2005 Wink is a mixture between QRP2001, SDR-1000 and other concepts. It sounds great in SSB. I demodulate LSB, USB or both but not AM. Yes, yes I know M = s
Hi I want to use digital techniq to implement AM/FM modem for a transceiver. Now I need some help about it such as the best scheme for designing or ADC, DAC and DSP selection. The IF signal is 1.4MHz. Another import thing is the MIPS that these modulations/demodulations need. Thank you. Agha
Hi guys can you please help me i am simulating an fm system here is the code below I am having a problem on the demodulation side I am trying to demodulate using PLL desgning (Phase Lock Loop). But it is giving me an error at last line R has to be positive number I think its R please help I am giving up = mp3read('jem.mp3'); s
I too am doing similar work, any body with any suggestions??
i am new to vhdl. Is it possible to design fsk, psk modultion and demodulation in MODELSIM( bcoz thats what i have), i dont know how to bring sine wave in that..can anyone help me. otherwise anyother simulation tool is available for this???
I am working on project .. i need to simulate bluetooth modulation and demodulation in Matlab. if anyone has anymaterial or matlab design of blocks or anything pls give me link.... or any bluetooth documantaion...
In AM modulation the modulator is a multiplier i.e. a mixer. In digital modulation the mixer is just a part of the whole modulator/demodulator. In FM modulation the modulator is basically a VCO, so if you send an FM signal to a mixer you have just upconversion or downconversion. Bye
hellow , i am in need of pulse position modulation demodulation code in Verilog, i wil b thankful to those who help... regs, sunil
I need a help in this project MATLAB GUI for AM modulation and demodulation, it must include four types of AM (DSB-LC, DSB-SC ,SSB). The GUI will display signals in time domain and frequency domain. The GUI must be able to modulate and demodulate various common signals and speech signals (read from .wav files). And the user can change the parame
You will use Communications Toolbox, which provides amdemod function for amplitude demodulation and ammod function for amplitude modulation. And a large number of useful functions are also provided. I think it will help you a lot.
I am doing the ultrasound signal doppler demodulation. Specificly, with a singal with f0, and another signal f0+fd. I want to get the fd. What kind of chip could realize this ? Thanks!
Hi fellas, I am doing CCK demodulation by 802.11 standard. I have a signal which is a real WLAN packet but i am doing the decoding off line. I know where the CCK modulation starts in a WLAN packet so i starts decoding from that very instant. My operation steps are listed below: 1. I downsample my data from 200Mbps to 11 Mbps 2. At 11Mbps, i ad
Hi, I've just studied FPGA for a short time. At that time, I've built successfully a QAM-16 modulation project using VHDL code. But now, when I try to build QAM demodulation, I've met a big problem. I've done the demodulation in matlab, but in FPGA, I can not synchrolize the receive signal with the carrier recovery. I mean I can't recover symbol
If x="10101100",How to sampling and plot s(t),y1(t),y2(t),x1,x2,I need MATLAB code,Thank you very much more information we needed.
Hi,...i am working on an SDR project ,...i need the AM recorded files for signal processing, (demodulation) ....can anybody give me some link to get them (with the frequency indicated)
Can anybody kindly provide me the links or upload simulink models for AM/FM demodulation. Thanks in advance
It may be the case, that you have an unusual high Q LC tank, or antenna matching filter. But simply tuning it to the carrier should remove any sideband unsymmetry. As another explanation, the same buggy SDR may be utilized at the receiver sites.
f i set local oscilator frequency equal with carrier frequency then i have demodulate signal. You get some kind of demodulated signal, but not the intended base band signal, not even for AM. With "zero IF" or homodyne receiver technique, there'a small problem with RF to LO phase relation. You may want to evaluate this in an
Hi friend, In fact i am very busy last days and still busy, But I will write here what i know in simple words: To do demodulation for this type of modulation you need to multiply each filtered signal with its corresponding carrier such as the cos by the cos and the sin by the sin, If you have only a sin then you must shift it by 90 degrees to
I have to write program using C++, which can demodulate AM and FM signals saved in .wav files. ( signals are saved using PC sound card ) What kind of alghoritm will be the easiest to implement in C++? Is someone who wrote simmilar apliccation?