127 Threads found on edaboard.com: Am Demodulation
I am a newbie to demodulation and carrier synchronization.
For low power demodulation the data after ADC in RX, what are the various algorithms algorithm available? A google search returned Viterbi, LDPC, Matched filter etc.
For optimum demodulation, one also needs carrier synchronization for good BER performance? What (...)
Digital communication :: 11-25-2016 12:28 :: deba_fire :: Replies: 2 :: Views: 401
I am working in implementation of chirp slope keying modulation and demodulation in MATLAB.
Simulations that I completed are:
1. Chirp signal(up and down chirp) generation completed
2. Linear frequency modulation/chirp signal simulated
3. Random data generation completed
4. finally, i need
Digital Signal Processing :: 06-07-2016 07:24 :: sekharece413 :: Replies: 0 :: Views: 382
I am working in implementation of chirp slope keying modulation and demodulation in MATLAB.
Simulations that completed are:
1. Chirp signal(up and down chirp) generation completed
2. LFM with up-chirp and down-chirp simulated
Digital Signal Processing :: 05-24-2016 07:42 :: sekharece413 :: Replies: 0 :: Views: 478
Envelope of SSB rectified with detector does not recover intelligible audio. AM has envelope which after rectification gives normal audio. One of method for demodulation of SSB is to first mix SSB with carrier to get AM and then rectify it.
RF, Microwave, Antennas and Optics :: 09-02-2015 07:56 :: Borber :: Replies: 16 :: Views: 1065
I am working on an audio file in simulink .I have given the A-law compressor and expander for source coding and used digital pass band modulation and demodulation and unbuffer and buffer but still Im not getting an output without noise. Im unable to find out where is the mistake and how to rectify it. Please help me to solve this.
Digital communication :: 12-02-2014 20:32 :: ramya priya :: Replies: 0 :: Views: 485
My project is to demodulate a SSB signal using a Freescale DSP Micro. I have completed the code for the FFT, filter and then IFFT with overlap add etc. Sampling is done at 20 kHz.
What I am not sure if is how exactly is the SSB demodulation done with one complex FFT.
What I know is:
The I and Q channels are fed into the Real and Imaginary va
Digital Signal Processing :: 11-07-2014 14:01 :: conradza :: Replies: 0 :: Views: 833
For AM, you can throw away the Q, and take the amplitude of I
and there's your audio stream, badda-bing. Using the 31kHz as
the "IF" I suppose would work but might lose you some audio
quality (like you care, about AM audio quality to that degree).
I think you'd have less software burden if you could notch
filter the incoming signal, but if your ge
Digital Signal Processing :: 09-07-2014 22:54 :: dick_freebird :: Replies: 12 :: Views: 902
I have downloaded I/Q samples of AM modulated signals (Radio broadcast) that contains 2 stations. one centered at 0 Khz and other at 8 Khz.
I am able to play 0 Khz stations by demodulation. now i want to shift (down-conversion) the 8 Khz signal to 0 Khz. I understand the process and studied various books but by applying what i have studied i
Digital communication :: 06-28-2014 05:00 :: Masood_786 :: Replies: 1 :: Views: 704
I have a question about direct down-conversion mixer
Right now i have a RF AM signal like this.
It has it's carrier freq & signal freq
we know that we can generate the above waveform by using a single mixer
My question is ,can we demodulate this AM signal by a using a Direct down-conversion mixer
RF, Microwave, Antennas and Optics :: 03-31-2014 03:51 :: nonsense999 :: Replies: 1 :: Views: 788
I am trying to implement 16 QAM MODEM & phasing a problem of demodulation of received signal.
I want to know the algorithm for thresholding a received signal.
PLD, SPLD, GAL, CPLD, FPGA Design :: 01-16-2014 09:26 :: devangkb :: Replies: 0 :: Views: 381
i am currently creating a code where the signal vector will be segmented out to a certain amount of bits and i will add noise to it and demodulation and get the BER. But my BER vs SNR plot graph looks very wierd to how a normal BER vs SNR graph should look like. I would appreciate if someone can tell me what is wrong with my code or something I am
Digital communication :: 10-20-2013 20:29 :: mewthturn :: Replies: 1 :: Views: 1304
We often see phasenoise being represented in dBc/Hz or deg rms.
I am not very sure ,how to use these phasenoise values to find out whether
the achieved phasenoise at a transmitter output is sufficient for an authentic
or error free demodulation at receiver end? I believe these values are more
stringent for say 8-psk than bpsk demodulation.:?:
RF, Microwave, Antennas and Optics :: 10-10-2013 17:14 :: afz23 :: Replies: 5 :: Views: 618
for details of fm/am modulation and demodulation refer the book
electronic communication systems by george kennedy
here you will get the full idea fm / am radio
Hobby Circuits and Small Projects Problems :: 08-22-2013 21:18 :: pradeep.g.belchada :: Replies: 20 :: Views: 1675
I am building a CDMA simulation software and i have a question?
I know that CDMA based on spreading data with PN codes by preforming xor operation between each bit of data to the PN sequence and also for multi user i need to spread the data by walsh code before i spread it by PN sequence(am i right????).
So my question is :In order to crea
Digital communication :: 06-10-2013 17:54 :: iliya24 :: Replies: 0 :: Views: 918
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!!
To detect the modulation signal from the AM spectrum, you need literally a "crystal s
Analog Circuit Design :: 05-29-2013 15:19 :: jiripolivka :: Replies: 4 :: Views: 458
I want to know about how to construct a 43 tap FIR filter in verilog using "Generate" function in verilog, if you could please guide me, I am trying to make "costas loop " for demodulation and extraction of 8bit data word from 10 bit encoded BPSK transmission at 2 MHz, the system will work at CLK - 200MHz.
I am trying to get all the modules in
PLD, SPLD, GAL, CPLD, FPGA Design :: 03-27-2013 06:11 :: vishal.takodara :: Replies: 0 :: Views: 814
I am implementing an OFDM modulation scheme as part of an LTE project in C/C++ and then testing it on a DSP board. I am using turbo coding with soft decision decoding. On the receiver side of the LTE system, I need to perform a soft demodulation (16-QAM and 64-QAM) so I can feed real values to the turbo coder for decodin
Digital communication :: 03-23-2013 23:11 :: David83 :: Replies: 2 :: Views: 2723
I am new to Digital Communications and MATLAB. I am learning to implement modulations and demodulations in MATLAB.
I have an amplitude modulated signal at the receiver input. I am trying to recover the message bits after the demodulation.
Following are the parameters of the modulated signal:
Carrier frequency = 22000 Hz (can be
Digital communication :: 03-21-2013 16:50 :: v_suma :: Replies: 0 :: Views: 1315
?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
Elementary Electronic Questions :: 02-23-2013 03:18 :: idmond :: Replies: 3 :: Views: 776
I agree. CA3012 cannot be used for AM demodulation at all. The only internal stage that can be used in a AM receiver is the audio preamplifier, which is available at pin 14 and pin 12.
RF, Microwave, Antennas and Optics :: 01-13-2013 11:20 :: vfone :: Replies: 6 :: Views: 591
I am not sure if this answers one of your questions: Are you aware that signals of the PLL transfer function are not voltages but the PHASE?
That means: The VCO acting as an integrator regarding the phase and, thus, contributes the order n=1 to the overall transfer function.
That means: With a first-order loop filter the PLL order is n=2.
Analog Circuit Design :: 01-09-2013 11:56 :: LvW :: Replies: 2 :: Views: 1961
I have developed a simple costas loop for BPSK demodulation. It is working fine for 8Mbps data rate BPSK. The overall sampling freq is 125 MHZ. Inside the loop, the corresponding FIR and loop filters are running at 25 MHz. The lock range achieving is +100 KHz to -100 KHz of centre 30 Mhz.
Now, I am updated the same for QPSK demodulation. The up
PLD, SPLD, GAL, CPLD, FPGA Design :: 12-21-2012 07:37 :: demod :: Replies: 0 :: Views: 948
Can anyone help me figure out hwo to solve the issue with the DPBSK demodulation block.
I am running into issue with that.
I am not able to achieve and demodulated signal at the FFT sink.
I am able to see that the signal is being received at the USRP source but there is some problem which i am not able to figure out after the sig
Digital Signal Processing :: 12-01-2012 21:27 :: prithvi1989 :: Replies: 0 :: Views: 992
I am not sure it is the solution you are looking for but the AD8302 will measure phase and amplitude. While it works up to 2.7GHz, it also works at low frequencies as well - I have used it well below 1MHz. Not cheap though.
Analog Circuit Design :: 11-26-2012 21:51 :: keith1200rs :: Replies: 8 :: Views: 799
jtrent, your assumption is only true for older terrestrial TV broadcasts. In Europe, and I guess most other places, almost all video is either digital (QAM or OFDM) or FM from satellite.
From the data sheet it looks like that IC decodes FM video and can decode AM or FM sound.
Elementary Electronic Questions :: 06-12-2012 21:37 :: betwixt :: Replies: 3 :: Views: 1454
hi i need vhdl code of fm demodulator.if anyone is having it plz mail me at (email@example.com).further i have to burn that code on fpga kit spartan 3e vertex 5 can any one tell me how can i do it becoz i am new to fpga's kit.plz inform me asap i have to do the project in one week
PLD, SPLD, GAL, CPLD, FPGA Design :: 05-07-2012 14:57 :: husnain681 :: Replies: 1 :: Views: 1461
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
Digital Signal Processing :: 04-15-2012 11:00 :: konradb :: Replies: 0 :: Views: 769
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
Analog Circuit Design :: 02-28-2012 19:19 :: klystron :: Replies: 6 :: Views: 2525
I am trying to implement an Amplitude shift Keying ASK modulation and (synchronous)demodulation in Matlab,I have to use a PLL at the receiver end for demodulation.The task is to read a hexadecimal file (attached) and convert it to a binary stream. the binary stream is the modulated with a carrier frequency of 30,000 Hz. The channel
Digital Signal Processing :: 12-18-2011 13:31 :: ultraviolet_ray :: Replies: 0 :: Views: 1633
length = 1000 ;
Stream = randint(1, length) ;
Mod = 2*Stream -1 ;
SNR = 10 ;
Recv = awgn(Mod, SNR) ;
Demod = (Recv >= 0) ;
Digital communication :: 11-21-2011 08:16 :: Ahmed Alaa :: Replies: 2 :: Views: 4541
i am a newbie to vhdl.. i want to implement afsk demodulator in a fpga .... if any one can help me in getting started with the project ??
what are the different approaches in emplementing afsk demodulator ??
PLD, SPLD, GAL, CPLD, FPGA Design :: 10-05-2011 23:00 :: santhu0025 :: Replies: 1 :: Views: 1132
I am using two TMS320C6713, one for BPSK modulation and another for demodulation.
When I am giving the output of BPSK modulator to another kit for demodulation as an input and multiplying it with a sinewave, I am getting the waveform which is not synchronized.
Can anyone here please guide me to get a synchronized output.
Thanks in advanc
Digital Signal Processing :: 08-19-2011 10:29 :: php.sandy :: Replies: 1 :: Views: 1238
why we are going for am and fm modulation and demodulation?
Elementary Electronic Questions :: 07-19-2011 17:39 :: jagannathan :: Replies: 1 :: Views: 588
Hi. I have the same problem. I am trying to demodulate BPSK signal and here is my way: BPSK signal .* carrier => integral => compare with 0 (if >0 is 1 and <0 is -1)=> recover original signal.
Use can follow this link: but if we use LPF, the BER is really high. My teacher said "use inte
Digital Signal Processing :: 02-27-2013 07:13 :: sadsorry :: Replies: 3 :: Views: 1715
i am having problem in plotting the demodulated signal, graph shows nothing, can anyone help....
and further , How to calculate BER?
Here is the code......
clear; % Clear all stored variables
Ns=100; %Number of data bits
NRZ=2*data-1;% Converts 0 t
Digital Signal Processing :: 04-08-2011 14:35 :: w_bwr :: Replies: 0 :: Views: 698
I would like to understand what is CCK Modulation? How is spreading achieved in CCK ? What is the difference between CCK Modulation and Spreading using Barker Code.
I am trying to implement the modulator and demodulator for CCK Modulation used in IEEE 802.11b. What is the optimal technique in terms of hardware realization for demodula
RF, Microwave, Antennas and Optics :: 04-05-2011 15:34 :: kirancshet :: Replies: 1 :: Views: 3449
Hello, I am implementing the DQPSK modulator and Demodulator. I was successful in implementing the DQPSK modulator. But, unfortunately, I could recover the samples from the modulated signal.
As the help indicates and I quote, "If the Output type parameter is set to Integer, then the block maps a phase difference of
Theta + pi*m/2
to m, whe
Digital communication :: 04-05-2011 09:07 :: kirancshet :: Replies: 0 :: Views: 912
most log amplifiers only have a dc output, so how is that going to get thru your mixer?
RF, Microwave, Antennas and Optics :: 04-01-2011 10:15 :: biff44 :: Replies: 14 :: Views: 1454
Can you suggest me how can we demodulate the DQPSK signal in Simulink, using the Xilinx blockset. I am implementing in FPGA, hence I need to use only the xilinx blockset.
Any pointers for the tutorial would be helpful as well.
Digital Signal Processing :: 03-29-2011 12:01 :: kirancshet :: Replies: 0 :: Views: 1622
I am trying to demodulate an OFDM signal at the receiver side to achieve the transmitted square wave.
Does anyone have any ways or suggestion to achieve that?
Many thanks in advance
Digital communication :: 02-25-2011 11:22 :: Girly_girl :: Replies: 0 :: Views: 741
I am doing turbo decoding but want an algorithm for QPSK demodulation that is used before the turbo (one received voltage value mapped to M soft-decisions, with M being the M in M-PSK.). Any suggested algorithm ?
Digital communication :: 02-19-2011 15:03 :: Ahmed Alaa :: Replies: 0 :: Views: 759
I have a project that is about Qpsk demodulation with FPGA.But I am new on this subject.I want to learn which algorithm is used for demodulation and I need e book related to demodulation techniques.
Digital Signal Processing :: 01-29-2011 16:58 :: celine37 :: Replies: 1 :: Views: 1689
I am studying how bad is demodulation in case of not having a real match filter as the first block in the reception of the signal. do you know where could I find curves which take into account this error in the filter?? The only curve I found is the teoretical one and I guess, its behaviour is not the same
Thanks in advance!!
Digital communication :: 01-23-2011 14:09 :: Xavipersonal :: Replies: 0 :: Views: 1718
I would like to know in which situations is not possible the use of a Band Pass Filter in the reception of a communication.
I am implementing and alternative system and it would be nice to know when is better to use it in stead of a BPF and a demodulation signal, for example.
Thanks a lot in advance
Digital communication :: 01-14-2011 18:38 :: Xavipersonal :: Replies: 3 :: Views: 593
I am new to MATLAB and am trying to implement a FSK communication system.
In the coherent detector part, I am trying to build the integrator block.
So right now i have a lot of samples which have come out of the multiplier block. With these sample values in hand how can I integrate or perform an equivalent operation for the dur
Mathematics and Physics :: 12-02-2010 23:47 :: akhil28288 :: Replies: 0 :: Views: 1400
i have to narrow band pm modulation and demodulation is simulink. i have done modulation and for demodualtion i am doing envelope detection using hilbert transform. but its giving error .can any one please rectify this error. i am attaching the simulink file.
Digital Signal Processing :: 11-26-2010 11:32 :: khan001 :: Replies: 0 :: Views: 2162
Q1. I am using bi-polar NRZ for mapping the signals and simply converting each bit in 1 or -1 and transmit or, due to BPSK I have to convert the these (-1, 1) bit to energy signal waves?
or Simply do I transmit 1 or -1?
Q2. Let suppose after passing awgn channel my signals corrupted and I have received corrupted signals which is re
Digital communication :: 10-28-2010 14:36 :: FRB :: Replies: 0 :: Views: 2150
Please put up a model of what you are trying to do.
I'd also suggest that you start with BPSK, figure this problem out and go back to 16-QAM
Digital communication :: 10-25-2010 22:09 :: Communications_Engineer :: Replies: 2 :: Views: 1480
Is there a desktop or a PC slot card or an external module (USB) universal VHF to L-band receiver capable of AM, FM, SSB and also digital (IQ) demodulation?
Additionally it should have an adjustable (IF or baseband) bandwidth, let say from few kHz to 10MHz (in some discrete steps).
Something like a TV tuner (Skystar2), but more for general us
RF, Microwave, Antennas and Optics :: 09-24-2010 13:16 :: rfmw :: Replies: 1 :: Views: 879
Matlab coding of GSM TRANSCIEVER
i am Master student and doing a project on EDGE-GSM transciever.
i need help in coding of all parts of transciever..
i.e, 1. channel coding
3. burst assembler
Digital communication :: 09-18-2010 21:57 :: Andys1729 :: Replies: 0 :: Views: 1157