Tag Archives: fdma

Resource Block & Physical Resource Block in LTE

What is Resource block in lte? :- A resource block is the smallest unit of resources which allocated to a user. The resource block is 1 slot long in time and 180 kHz wide in frequency. Resource Block Multiplex multiple…

What is the difference between 4G and 4G LTE?

Many people use the terms 4g and 4g interchangeably, but they are not the same. Lets find out the difference…. Features of 4g 4G is the next step above and a 3g replacement, offering faster speeds for users who stream…

BS Transmitting and Receiving Process in Wimax.

Transmitting:  After being processed at the MAC layer, the downlink data is sent to the physical layer inthe format of MAC PDU. The MAC PDU arranges the data block size according to the allocation results of radio resources at the…

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 single-user OFDM in terms of robust multipath suppression and frequency…

How Data Transmission in UL in LTE?

In UL, the UE has no dedicated resources to transmit directly when new data arrived in the buffer from higher layer.  It requests resources to transmit them.  It receives radio resources.  It transmits them.   The scheduling request is sent…

The Benefit of OFDM & OFDMA in Wimax

Less complex modulation. OFDM is a simpler modulation technique that is better suited to deployments that do not require support for mobility.  License-exempt bands. Mobile services require licensed spectrum to provide coverage in wide areas. Fixed deployments, however, have often…

Emergence of Standards-Based Technology

In 1998, the Institute of Electrical and Electronics Engineers (IEEE) formed a group called 802.16 to develop a standard for what was called a wireless metropolitan area network, or wireless MAN. Originally, this group focused on developing solutions in the…

OFDMA Parameter for LTE

How Many OFDMA Parameter for LTE? Which is OFDMA Parameter for LTE ? The width of a Sub-carrier is 15 kHz whatever the bandwidth The bandwidths are: 1.4, 3, 5, 10, 15 and 20 MHz Note that in LA1.1, only…

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. mx 180 KHz) Equalization is required in the SC-FDMA receiver…

Difference between DL and UL in LTE

what is main Difference between DL and UL in LTE ? OFDMA Advantages Robust against narrow-band co-channel interference Robust against Intersymbol interference (ISI) and fading High spectral efficiency Efficient implementation using FFT Drawbacks High Peak-to-Average Power Ratio The power limitation…

OFDMA Transmitter in LTE

How OFDMA Transmitter in LTE ? In the downlink, OFDM is selected to efficiently meet E-UTRA performance requirements. With OFDM,  it is straightforward to exploit frequency selectivity of the multi-path channel with lowcomplexity receivers.  This allows frequency selective in addition…

OFDMA Principles in LTE

There are several ways to transmit over the frequency band and to share the resource between several devices.   What is TDMA,CDMA & FDMA ?   1.TDMA • The users are separated by the the time • Used by the…