What are the Advantages of OFDMA in Wimax ?

 OFDMA is essentially a hybrid of FDMA and TDMA: Users are dynamically assigned subcarriers (FDMA) in different time slots (TDMA) . The advantages of OFDMA start with the advantages of...
Article Topics :

access, cell, fdma, frequency diversity, ofdm, ofdma, subcarrier, tdma, telecom, uplink, user

How Reference signals Map in LTE?

For channel estimation different types of reference signals are in use: - Cell specific reference signals. - MBSFN reference signals. - UE specific reference signals CELL-SPECIFIC REFERENCE SIGNALS These signals...
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4 cell specific reference signal, cell, lte, lte reference signal, lte reference signal frequency shift, MBSFN, mbsfn reference signal mapping, Reference signals, subcarrier, subframe, telecom

SC-FDMA Receiver Benefits in LTE

DFT spreading of modulation symbols reduces PAPR In OFDM, each modulation symbols “sees” a single 15 kHz subcarrier (flat channel) In SC-FD-A, each modulation symbol “sees” a wider bandwidth (i.e....
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SC-FDMA Receiver, sc-fdmafdma, lte, ofdm, receiver, sc fdma, subcarrier, telecom, uplink

UL Allocation (SC-FDMA) in LTE

SC-FDMA utilizes single carrier modulation, DFT-spread orthogonal frequency multiplexing, and frequency domain equalization. LTE uses OFDMA on the DL. It allocates DL bandwidth to the user based on resource blocks,...
Article Topics :

ofdma, subcarriers, transmitted, symbol, spreadamplifier, amplitude, bandwidth, cell, dl, enodeb, fdma, ofdma, orthogonal, resource block, subcarrier

Ways to transmit training symbols: preamble or pilot tones in Wimax

There are two ways to transmit training symbols: preamble or pilot tones. Preambles entail sending a certain number of training symbols prior to the user data symbols. In the case...
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Ways to transmit training symbols: preamble or pilot tones in Wimax, pattern transmits training, symbols, preamble, interpolation, subcarriers, orthogonalcarrier, cdma channel frequency calculator, fft in wimax, mimo, ofdm, subcarrier, symbol

What is SC-FDMA and how it works in LTE?

One of the major drawbacks of an OFDMA system is, that the transformation of a complex symbol mapped sequence (e.g. BPSK, QPSK, etc.) onto a small set of subcarriers produces...
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fdma, lte, ofdma, sc-fdma lte, scfdma, subcarrier, symbol, telecom, transmitting carrier, uplink

Synchronization in LTE Mobile “Switch On”

Primary and Secondary Synchronization Signals occupy 2 blocks of symbols per 10 ms (central 72 subcarriers for all channel bandwidths). An example is shown below for 72 subcarrier- (1.4 MHz)...
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cell, lte, subcarrier, switch on LTE mobile, synchronization, telecom

Inter-Carrier Interference for OFDM

The price for the optimum subcarrier spacing is the sensitivity of OFDM to frequency errors. If the receiver’s frequency is some fractions of the subcarrier spacing (subcarrier bandwidth) then we...
Article Topics :

cost, frequency, interference, ofdma, ppm, receiver, signal, subcarrier, telecom, transmitter

Difference Between OFDM and FDM in LTE

Conventional multi-carrier operation as it is used for FDM works simply by selecting a number of center frequencies – one for each carrier to be used. The center frequencies must...
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aci, bandwidth, carrier, difference between conventional fdm and ofdm, difference between ofdm and fdm ppt, fdm, frequency, lte, ofdma, shaping filter, subcarrier, symbol, telecom

OFDM implementation in Detail

A typical OFDM transmitter is shown on the following figure. To reduce the amount of RF hardware required for OFDM the modulation process is split into two parts. A first...
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dac, filter, generator, hardware lte, lte, ofdm idft, ofdma, recevier, sampling, signal, spreading, subcarrier, symbol, telecom, transmitter, wave

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