What is the difference between OFDMA and SC FDMA why OFDMA is not used in both the directions?
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What is the difference between OFDMA and SC FDMA why OFDMA is not used in both the directions?
The main difference between an OFDM and an OFDMA (Orthogonal Frequency Division Multiple Access) system if the fact that in the OFDM the user are allocated on the time domain only while using an OFDMA system the user would be allocated by both time and frequency. For the uplink SC-FDMA will be used.
What is the difference between OFDM and CDMA?
OFDM stands for Orthogonal Frequency Division Multiplexing and CDMA stands for Code Division Multiple Access. OFDM is a multiple carrier system where in multiple carriers are packed very densely and all are allocated with data bits based on complex modulation scheme. CDMA on the other end is a single carrier system.
What is the difference between TDMA FDMA and CDMA?
In CDMA, all the stations can transmit data simultaneously. It allows each station to transmit data over the entire frequency all the time….Difference between FDMA, CDMA and TDMA :
| FDMA | TDMA | CDMA |
|---|---|---|
| The rate of data is low. | The rate of data is medium. | The rate of data is high. |
Why we use SC-FDMA in uplink?
SC-FDMA is preferred for LTE uplink mainly due to its advantage of having low peak-to-average power ratio (PAPR) during signal transmission. It is found that by increasing spreading factor symbol error rate is reduced for SC-FDMA system and for spreading factor of 64 for SNR=20 dB, SER is of the order of 10 -4 .
Why Ofdma is better than CDMA?
OFDM CDMA comparison Both OFDM and CDMA have significant benefits. OFDM can combat multipath interference with greater robustness and less complexity. Equalisation can be undertaken on a carrier by carrier basis. OFDMA can achieve higher spectral efficiency with MIMO than CDMA using a RAKE receiver.
What are the advantages of TDMA?
Advantages of TDMA:
- TDMA can easily adapt to transmission of data as well as voice communication.
- TDMA has an ability to carry 64 kbps to 120 Mbps of data rates.
What are the advantages of TDMA over FDMA?
Benefits or advantages of TDMA As TDMA makes efficient use of the spectrum, more number of users can use same spectrum than FDMA system. ➨The operational costs of TDMA networks are lower compare to traditional FDMA network.