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Because OFDM systems use orthogonal frequency(carrier),at the receiver the others copies from multipath has a different phases from the direct one, and by multiplying the generated carrier in the receiver with all received signal and integrated it over [-pi,+pi] only one the direct signal have (1) at the output and the others have(0) output.
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How you eliminate inter symbol interference in ofdm?
Inter symbol interference (ISI) in OFDM systems can be minimized by using a cyclic prefix. This involves adding a copy of the end of each OFDM symbol to the beginning before transmission. The cyclic prefix helps to mitigate the effects of multipath fading and reduces ISI by allowing the receiver to separate the OFDM symbols with a guard interval.
What is SISO-OFDM?
SISO-OFDM is an OFDM system with one transmit and one receive antenna.
What is a deck-stiffening truss?
it effectively eliminates the effects of torsion. :) =]
What are the advantages of mimo over siso and simo?
it remove the problem of multipath fadding. it remove the problem of multipath fadding.
What are the release dates for The Multipath Adventures of Superman - 1999 VG?
The Multipath Adventures of Superman - 1999 VG was released on: USA: 1999
Why was OFDM selected for WiMax?
OFDM (orthogonal frequency division multiplexing) is a technique for increasing the amount of information that can be carried over a wireless network. In frequency-division multiplexing, multiple signals, or carriers, are sent simultaneously over different frequencies between two points. However, FDM has an inherent problem: Wireless signals can travel multiple paths from transmitter to receiver (by bouncing off buildings, mountains and even passing airplanes); receivers can have trouble sorting all the resulting data out. Orthogonal FDM deals with this multipath problem by splitting carriers into smaller subcarriers, and then broadcasting those simultaneously. This reduces multipath distortion and reduces RF interference (a mathematical formula is used to ensure the subcarriers' specific frequencies are "orthogonal," or non-interfering, to each other), allowing for greater throughput.
How many sub channels does OFDM use for carrying data?
OFDM uses 48 subchannels for data and 4 are used as Pilot Carriers.
What is loss of orthogonality means in OFDM technology?
In OFDM, sub-carrier spacing is maintained in such a way that the maximum of one sub-carrier occurs at the minimum of the successive sub-carrier, a loss of orthogonality results if this pattern is not achieved in the sub-carriers of OFDM transmission. Loss of orthogonality is due to ISI, ICS, Frequency offset amongst the sub-carriers of OFDM.
Explain ICI in ofdm systems?
Multi Carrier systems like OFDM has the problem of Inter Carrier Interference(ICI), which results from the loss of Orthogonality between the sub carriers.This happens when the FFT is considered over duration where the subcarrier is non integer number of cycles, which would be the case when multipath is present and the guard time has amplitude is zero.This is reduced by use of cyclic prefix, where we transmit a copy the last part of the symbol followed by the symbol itself.This ensures Orthogonality over the FFT period in case of delayed multipath. yup...that's all from me. Regards Girish .V.V There are many methods to reduce ICI not only CP like Frequency domain equalization,Time domain windowing,Pulse shaping,Maximum likelihood estimation,Extended kalman filtering and ICI self cancellation.And any one have their own advantages. Naser
What is 'ofdm'?
Orthogonal frequency-division multiplexing
Which is not true about multipath signaling?
Multipath signaling refers to the use of multiple signal paths to transmit data, providing redundancy and reliability. It is not true that multipath signaling decreases data transfer speed; in fact, it can improve data transfer speed by utilizing the most efficient signal path available.
What encoding or modulation technology does 802.11 a use?
OFDM
