Questions tagged [ofdm]

OFDM stands for Orthogonal Frequency Division Multiplexing. It is a communications transmission technique that breaks the carrier into multiple sub-carriers (hence, the multiplexing in frequency).

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What are the Smallest Actual 5G NR Transmit Burst Elements?

What is the smallest single entity that is actually transmitted over the air as an isolated burst in 5G NR?: One 2-OFDM-symbol Mini-Slot at 125 μs, (one slot has a 62.5 μs minimum duration) One 14-...
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Minimum data rate for OFDM?

I'm relatively new to electronics, so sorry for my awkward understanding of topics. I'm just trying to wrap my head around some basic concepts here. From my understanding, in OFDM, the information ...
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How are the neat sinc function shaped carriers produced in OFDM?

I am learning about OFDM and QAM. Every explanation I have read illustrates how the separate carriers are sinc functions that are arranged to overlap in a nice orthogonal way so as to cancel out ...
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Butler Matrix simulation in Sonnet software

I am trying to replicate a 4 X 4 butler matrix using Sonnet Here is the sonnet design file : butler_matrix.son With conformal meshing (metal fill type) and course meshing, it still requires 14 GB of ...
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Maximum transmit power allowed for 802.11g

I'm learning about the 802.11 regs. In a book I'm using, "CCNA Wireless 200-355 Official Cert Guide (Certification Guide) 1st Edition by, David Hucaby (Author). Page 53", it has the following clause ...
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OFDM symbol period and minimum burst durations

I have been reading about cognitive radio using OFDM and literature on technologies like LTE and 802.11 variants. A useful value in the system analysis is the OFDM symbol period \$T_u\$. Is it ...
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In actual OFDM trasmitter, is the stepwise waveform after IFFT put on the carrier as it is?

I simulated OFDM on MATLAB,though,the spectrum of it is not white(flat shape). Why? IFFT circuit of actual transmitter uses higher IFFT order than the count of subcarriers? P.S. I simulated with the ...
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Differences between OFDM, OFDMA and SC-FDMA?

I understand that - multiple user scenarios lead to OFDMA in SD-FDMA at any point of time, all subcarriers carry the same symbol. What I want is to understand on what exactly differentiates them.
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OFDM numerical example

Am I correct in this example? For example, I have data a data stream like this 101100011100...11001001 .... . Let say a symbol is 64 bits. I will use 16 qam-ofdm. For this, I separate a symbol to 16 ...
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what is the performance of an OFDM system in one-path channel (Flat response channel),with no multi path propagation?

i work on modelling a OFDM system in a indoor optical wireless channel (LOS channel), since my channel is LOS there is no multi -path propagation , so the delay spread of my channel is much smaller ...
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VLC - OFDM with RPI3 [closed]

Edited, We want to transfer data in high speed's. we are using RPI3 for all the mathematics calculation. As we know the RPI dose not support ADC with high sample rate so it irrelevant for us. We ...
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Wireless channel interpretation [closed]

Is there a way to estimate how fast a channel changes with respect to time in practical applications? While evaluating doppler effect for a user we use the frequency at which the channel changes. How ...
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Guard bands in OFDM

Consider the use of OFDM in 802.11a (5GHz band) as shown in this picture taken from NI's White Paper: For a 20MHz channel with a frequency spacing of 0.3125MHz between the subcarriers, there are a ...