Search Engine

Am Demodulation

Add Question

127 Threads found on Am Demodulation
Hi All, 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 (...)
Dear sir/madam, 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
Dear sir/madam, 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
Why a peak envelope detector cannot be used for detection of an SSB signal alone? Why exactly? To detect SSB you need the carrier to obtain an intelligible audio output. Peak envelope detector outputs a voltage proportional to RF input power, so only the full AM RF signal can generate a correct audio output. Ple
Hi 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.
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
In short, how do you decode AM signal from I/Q samples into sound? In details, i made an SDR that uses a PC sound card as ADC. The local oscillator on it is set to 700KHz, there is a radio station at 731KHz. With existing software i verified that the hardware works - the station is here and i can hear it. Now, the goal is to make my own SDR
Hi 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
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
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.
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
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.:?:
Hello every body I want to now how can I build my own Fm circuit , I now there is a lot of prepared circuit but I want to build my own . I will be glad if you have any book or link that can help me , I already finish my electronics course and one communication course , but unfortunately I'm not able to construct this kind of circuit in these cou
Hello 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
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
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
Hi, 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 decoding. I have looked for i
Hi, 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
?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
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 I would really appreciate it if someone could help me. (Sort out some confusion :-)) I am intending to use the 74hc4046 to demodulate a FSK signal. The carrier centre frequency is around 165Khz and the deviation is around +/-2.5%. So I am using a frequency offset. (I am not using any frequency divider). The max signal frequency is around 4.8k
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
Hello friends, 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
Hi, I am generating sine signal with 125 KHz using micro controller and giving it to Capacitive(cylindrical shape) sensor. If the sensor out is low to read then i am using two amplification stages to increase signal amplitude. I am using multiplexer to select best signal from sensor out. The out signal also 125 KHz but there is a phase shift in t
Hi everybody, I am not very familiar with video standards. I need to know if I can demodulate an FM modulated video signal with TDA9886. On the datasheet of TDA9886, it claims that it is a demodulator for FM TV. However, the block diagram given in the datasheet looks more like an AM demodulator for video and FM demodulator for sound. I attached
hi i need vhdl code of fm demodulator.if anyone is having it plz mail me at ( 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
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
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
Hi everyone. 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
length = 1000 ; Stream = randint(1, length) ; Mod = 2*Stream -1 ; SNR = 10 ; Recv = awgn(Mod, SNR) ; Demod = (Recv >= 0) ;
hi .. 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 ??
Hi, 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
why we are going for am and fm modulation and demodulation?
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
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 data=randint(Ns,1); subplot(3,2,1); stem(data,'filled') title('Samples'); ylim(); NRZ=2*data-1;% Converts 0 t
Hello, 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
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
hello I am building a direct conversion HF receiver (like R1 and R2 ones) that uses a mini circuits mixer with high dynamic range. By connecting the mixer directly to the antenna the dynamic range is at maximum. If I connect an amplifier at the input, to increase sensitivity, this decreases dynamic range. I am wondering, what if I try to make
Hello, 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. Regards Kiran
Hello all, 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
Hi all, 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 ? Thanks :)
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. Thanks
Hi there, 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!!
Hi, 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
Hello guys, 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
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.
Hi there, 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
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
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
Matlab coding of GSM TRANSCIEVER hi, 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 2. interleaver 3. burst assembler 4.modulation 5.demodulation 6.deinterleaver decoding [SIZE=1