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

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

Hi, How the pilot symbol assisted QAM works ? What are the symbol information sent on this Pilot ? It's in the same frequency band than...

Hi, How the pilot symbol assisted QAM works ? What are the symbol information sent on this Pilot ? It's in the same frequency band than the QAM modulation ? I think we send a BPSK pilot over the QAM modulation in time duplex ? Do you have good paper on that, I found nothing over google... Thanks

Hi all can any one tell me how to do 16, 64 non-uniform modulation in matlab,and how to calculate the distance between points, BER Thanks

Hi all can any one tell me how to do 16, 64 non-uniform modulation in matlab,and how to calculate the distance between points, BER Thanks

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...

I'm looking for some DOS/Win32 software that will emulate a Bell 103 and ITU-T v.21 modem that uses a WAVE format file or a computer's sound...

I'm looking for some DOS/Win32 software that will emulate a Bell 103 and ITU-T v.21 modem that uses a WAVE format file or a computer's sound card for the modulation/demodulation audio signal output/input. These modems use AFSK modulation at 300 baud and 300 bps, at the following frequencies (in Hertz): Bell 103 Originate 1170 = Carrier 1070 = Space (Carrier - 100Hz) 1270 = ...

Hi all, I am new in WiMax and I intend to construct the table of modulation, SNR and BER.. does anybody know how can I do it and by which...

Hi all, I am new in WiMax and I intend to construct the table of modulation, SNR and BER.. does anybody know how can I do it and by which equation ? I mean the table can be like the following: SNR modulation type data rate BER --- --------------- -------- ---- thanks for any help, Ashlie

Hello all, I have a question about coding gain for a convolutional code. In the books that I have, the coding gain is presented in the form of...

Hello all, I have a question about coding gain for a convolutional code. In the books that I have, the coding gain is presented in the form of graph of BER vs Eb/No for a given modulation format, typically BPSK. The coding gain is the horizontal distance between the uncoded and coded curves on the graph. My question is, what if I change the modulation format to FSK instead? I understand...

I am working on AD9857 which copmrises an IQ modulator and in fact is a quadrature up convertor Using 14 bits I Q input data , I want to try out...

I am working on AD9857 which copmrises an IQ modulator and in fact is a quadrature up convertor Using 14 bits I Q input data , I want to try out various modulation schemes like AM, FSK,FM,BPSK,GMSK, QPSK and QAM. I`ve tried IQ modulation in different (analogue) shchemes with MATLAB using IQ in form of analog signals . I would like some help on simulation of the quad modlr block with MATLAB code...

What type of hardware is typically used for frequency modulation?

What type of hardware is typically used for frequency modulation?

Hi, I have a question about channel coding. As I know, coding is used for improving system performance. At the same time, coding will result...

Hi, I have a question about channel coding. As I know, coding is used for improving system performance. At the same time, coding will result in lower spectral efficiency, except TCM. For higher modulation, the coding gain is useful only when its performance is better than that of lower order modultion without coding. Except TCM, other coding schemes are general of bandwidth expansion type....

Hi i am trying to implement 16QAM modulation with effect of transponder nonlinearity i got transponder power input and output values and i have...

Hi i am trying to implement 16QAM modulation with effect of transponder nonlinearity i got transponder power input and output values and i have to pass my modulated signal through this nonlinear channel but am not getting how to perform this function . so if anyone here has done such sort of work i.e. implemented a satellite nonlinear channel with any modulation scheme please let me know how to do...

Hi, I read this statement from a book "The bit error probability for QPSK modulation is the same as for BPSK, and hence, the results for BPSK...

Hi, I read this statement from a book "The bit error probability for QPSK modulation is the same as for BPSK, and hence, the results for BPSK can be used also for the QPSK case". The author of the book simulated the BER performance for BPSK modulation in multipath and AWGN channel. May I know how true is this statement? Under what scenario can I make such an approximation? Where can I find t...

Hi Gentle comp.dsp Denizens, The September issue of the JAES has an interesting article on noise power modulation in delta sigma modulators by...

Hi Gentle comp.dsp Denizens, The September issue of the JAES has an interesting article on noise power modulation in delta sigma modulators by Lokken et al. I was wondering if folks agree with his conclusions in section 1.2, where he states essentially that a 1-bit delta sigma modulator will have noise power modulation whether dither is used or not. One thing find odd is that in section ...

Hi, I am trying to implement a Nicam modulator in a fpga. The Nicam modulation is a digital sound modulation of analog TV, and use DQPSK. I...

Hi, I am trying to implement a Nicam modulator in a fpga. The Nicam modulation is a digital sound modulation of analog TV, and use DQPSK. I have some problem when implement the digital up converter(DUC) in fpga. The DUC comprise the cascade of pulse filter, CIC compensation filter CIC filter, and then multiply with carrier generated by a NCO. The interpolator of the pulse filter and ci...

Hi, I am looking for matlab source code to simulate adaptive modulation. can anyone help me? regards, Azadeh

Hi, I am looking for matlab source code to simulate adaptive modulation. can anyone help me? regards, Azadeh

Hi to all, I'm a student, I'm currently studying: AM, PM, FM, PCM modulation, noise impact on signal etc. I'd like to be able to graphical...

Hi to all, I'm a student, I'm currently studying: AM, PM, FM, PCM modulation, noise impact on signal etc. I'd like to be able to graphical view spectrum of baseband and bandpass signal implicated . I'd like to know, if there is any software, that could help me to be better understand the matter, where I can manually input the function which represent the signal eg. S(t) = Ac [ 1 + cos ( 2 ...

Hi All, I am trying to figure out the *real* motivation behind using MLSE (Maximum Likelihood Sequence Detection) as opposed to a...

Hi All, I am trying to figure out the *real* motivation behind using MLSE (Maximum Likelihood Sequence Detection) as opposed to a symbol-by-symbol detection that maximizes the log-likelihood function. As a tangible example, the standard optimum receiver for CPM (Continuous-Phase Modulation) signals is defined to be a correlator followed by an MLSE detector (Ref. Digital Communications by J...

Hi, My RF hardware accepts IQ data in digital form, and generates the RF signal on the trasmit chain. Similarly on the recieve chain it...

Hi, My RF hardware accepts IQ data in digital form, and generates the RF signal on the trasmit chain. Similarly on the recieve chain it downconverts the signal and generates a digital IQ data. I need to generate the baseband IQ data in the software in the transmit chain and similarly recover the message data from this baseband IQ data. Could some body throw light on how to do this, and if th...

Hi, I'm working on techniques in order to compute center frequency of MAPSK transmission. I foud work based on the computation of the index of...

Hi, I'm working on techniques in order to compute center frequency of MAPSK transmission. I foud work based on the computation of the index of maximum of (fft(s^M)) for MPSK transmission only (M is the modulation order). Are this formula OK for APSK transmission (like 16QAM or 16 APSK). I don't think so because different phase values are used in those cases. Otherwise could you give some help,...

Dear Friends, Till now I am doing on Speech/Audio Coding Implementations on various DSP's. I am thinking to change my domain to Wireless...

Dear Friends, Till now I am doing on Speech/Audio Coding Implementations on various DSP's. I am thinking to change my domain to Wireless Communication, specifically to base band processing and modulation side. I need how to start this? When even I type in the internet I am getting plenty of stuff and don't know what and how to start. I will be glad if any body can give suggestions on thi...