Comments on: BER for BPSK in OFDM with Rayleigh multipath channel http://www.dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/ Signal Processing for Communication Thu, 04 Mar 2010 16:31:39 +0530 http://wordpress.org/?v=2.8.4 hourly 1 By: Ishwinder http://www.dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/#comment-20614 Ishwinder Tue, 16 Feb 2010 05:40:38 +0000 http://www.dsplog.com/?p=225#comment-20614 Hi Krishna, I ran your script " BER simulation of BPSK in OFDM with Rayleigh fading channel" . I observed that even when i set the number of taps(nTap parameter in the script) to 1, it results in the same curve.Should we not see a improvement in the BER as the channel is changed from a 10-tap multipath fading channel to 1-tap flat fading channel? Please provide your comments on this observation. Thanks Ishwinder Hi Krishna,

I ran your script ” BER simulation of BPSK in OFDM with Rayleigh fading channel” . I observed that even when i set the number of taps(nTap parameter in the script) to 1, it results in the same curve.Should we not see a improvement in the BER as the channel is changed from a 10-tap multipath fading channel to 1-tap flat fading channel? Please provide your comments on this observation.

Thanks
Ishwinder

]]> By: Rayed http://www.dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/#comment-20570 Rayed Mon, 15 Feb 2010 21:32:00 +0000 http://www.dsplog.com/?p=225#comment-20570 Dear Mr.Krishna plz i need to calculate BER in QPSK -OFDM With multi path rayleigh fading can you help me and if you want how can use PN sequence in QPSK thanks alot Dear Mr.Krishna
plz i need to calculate BER in QPSK -OFDM With multi path rayleigh fading
can you help me
and if you want how can use PN sequence in QPSK
thanks alot

]]> By: samalqudah http://www.dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/#comment-20567 samalqudah Mon, 15 Feb 2010 18:05:57 +0000 http://www.dsplog.com/?p=225#comment-20567 hello mr. krishna, i would ask you a question regarding the rayleigh channel. how can i generate Rayleigh channel impulse response as ready numbers to be used in a program without using the rand()+j*randn() commands. in other words, i don’t want to have a loop or large number of symbols to get the plot of the prob. of error. I want to have a table of values for channel impulse response to be used for simulating a MIMO system. some papers do list down in a table the channel as complex values between each transmit and receive antenna to get a MIMO channel matrix, how did they get such values? this is exactly my question hello mr. krishna,
i would ask you a question regarding the rayleigh channel. how can i generate Rayleigh channel impulse response as ready numbers to be used in a program without using the rand()+j*randn() commands. in other words, i don’t want to have a loop or large number of symbols to get the plot of the prob. of error. I want to have a table of values for channel impulse response to be used for simulating a MIMO system. some papers do list down in a table the channel as complex values between each transmit and receive antenna to get a MIMO channel matrix, how did they get such values? this is exactly my question

]]> By: A Mehboob http://www.dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/#comment-20562 A Mehboob Mon, 15 Feb 2010 14:24:15 +0000 http://www.dsplog.com/?p=225#comment-20562 Dear Krishna I am bit confused here. You said "The scaling by sqrt(nFFT/NDSC) ensures that mean power ..." is it scaling by sqrt(nFFT/NDSC) or nFFT/sqrt(NDSC). Kind Regards A Mehboob Dear Krishna
I am bit confused here. You said “The scaling by sqrt(nFFT/NDSC) ensures that mean power …” is it scaling by sqrt(nFFT/NDSC) or nFFT/sqrt(NDSC).

Kind Regards

A Mehboob

]]> By: shah http://www.dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/#comment-20396 shah Sun, 14 Feb 2010 02:52:54 +0000 http://www.dsplog.com/?p=225#comment-20396 im new in matlab. Hello Krishna, thanks for ur nice work on OFDM. i want to design an OFDM simulator using matlab GUI so that we can easily to find out the BER vs SNR when i change any parameter on the modulation.. can u give me some idea which part i need to change mybe on the sampling freq or mybe on the no of sample.. and lastly from ur code which part i must to do so...please teach me...-shah- im new in matlab.
Hello Krishna, thanks for ur nice work on OFDM.
i want to design an OFDM simulator using matlab GUI so that we can easily to find out the BER vs SNR when i change any parameter on the modulation..
can u give me some idea which part i need to change mybe on the sampling freq or mybe on the no of sample..
and lastly from ur code which part i must to do so…please teach me…-shah-

]]> By: Ahmwd http://www.dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/#comment-19699 Ahmwd Sat, 06 Feb 2010 06:11:44 +0000 http://www.dsplog.com/?p=225#comment-19699 Hallo, your code had helped me a lot. Thank you very much. Please can you help me if the channel became Nakagami-m multipath fading channel. I do not know how to simulate Nakagami-m channel, please help me Hallo,
your code had helped me a lot. Thank you very much.
Please can you help me if the channel became Nakagami-m multipath fading channel.
I do not know how to simulate Nakagami-m channel, please help me

]]> By: eng_dina http://www.dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/#comment-19100 eng_dina Wed, 03 Feb 2010 00:03:51 +0000 http://www.dsplog.com/?p=225#comment-19100 Idon’t try to simulte cfo for mimo system only but for mimo ofdm I propose a new scheme that targets MMIO OFDM systems which have unsynchronized oscillators such that CFO of individual paths have to be estimated separately. This scheme may also apply to OFDM systems with multi-user access. The new method, which is similar to Moose’s method, estimates the CFO by measuring the carrier phase difference between 2 identical successive training sequences embedded in the preambles. In order to make CFO estimates be more time efficient,I allow 2 transmitter antennas transmit their training sequence concurrently in every time period, except the first and the last period. I use Frank-Zadoff code with different phase shifts in the training sequences in different antennas. Due to the good correlation property of Frank-Zadoff code, it helps reduce the interference caused by the concurrent transmissions from other antennas. please helpppppppppppppppppppppppp please reply me it's urgent Ineed the code it's really important and thanks alot Idon’t try to simulte cfo for mimo system only but for mimo ofdm I propose a new scheme that targets MMIO OFDM systems which have unsynchronized oscillators such that CFO of individual paths have to be estimated separately. This scheme may also apply to OFDM systems with multi-user access. The new method, which is similar to Moose’s method, estimates the CFO by measuring the carrier phase difference between 2 identical successive training sequences embedded in the preambles. In order to make CFO estimates be more time efficient,I allow 2 transmitter antennas transmit their training sequence concurrently in every time period, except the first and the last period. I use Frank-Zadoff code with different phase shifts in the training sequences in different antennas. Due to the good correlation property of Frank-Zadoff code, it helps reduce the interference caused by the concurrent transmissions from other antennas.
please helpppppppppppppppppppppppp
please reply me it’s urgent Ineed the code it’s really important and thanks alot

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